http://air.eng.ui.ac.id/api.php?action=feedcontributions&user=Agus.nuryadi&feedformat=atomccitonlinewiki - User contributions [en]2022-05-27T16:43:26ZUser contributionsMediaWiki 1.30.0http://air.eng.ui.ac.id/index.php?title=AIR_Students_Turbulence_Research&diff=57288AIR Students Turbulence Research2021-02-09T02:48:28Z<p>Agus.nuryadi: </p>
<hr />
<div><br />
{| class="wikitable" style="text-align: center; width: 500px; height: 500px;"<br />
<br />
!colspan="3"|Daftar Mahasiswa S3<br />
|-<br />
|'''No'''<br />
|'''Foto'''<br />
|'''Nama'''<br />
|-<br />
! 1<br />
| [[File:Gun Gun.png|80px|thumb|center]] || [[[[Gun Gun Ramdlan Gunadi]]]] <br />
|-<br />
! 2<br />
| [[File:Hariyotejo.jpg|80px|thumb|center]] || [[[[Hariyotejo Pujowidodo]]]]<br />
|-<br />
! 3<br />
| [[File:Candamis.jpg|80px|thumb|center]] || [[[[Candra Damis Widyawati]]]]<br />
|-<br />
! 4<br />
| [[File:Adi.jpg|80px|thumb|center]] || [[[[Adi Syuriadi]]]]<br />
|-<br />
! 5<br />
| [[File:Edo.jpg|80px|thumb|center]] || [[[[Muhammad Hilman Gumelar Syafei]]]]<br />
|}</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Agus_Prasetyo_Nuryadi&diff=57287Agus Prasetyo Nuryadi2021-02-09T02:47:38Z<p>Agus.nuryadi: Blanked the page</p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Paper&diff=53893Paper2021-01-07T02:08:09Z<p>Agus.nuryadi: </p>
<hr />
<div><br />
[[File:0001.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0002.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0003.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0004.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0005.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0006.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0007.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0008.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0009.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0010.jpg|1000px|thumb|left|alt text]]</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Paper&diff=53892Paper2021-01-07T02:07:16Z<p>Agus.nuryadi: </p>
<hr />
<div><br />
[[File:0001.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0002.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0003.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0004.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0005.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0006.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0007.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0008.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:0009.jpg|1000px|thumb|left|alt text]]<br />
<br />
[[File:00010.jpg|1000px|thumb|left|alt text]]</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:0010.jpg&diff=53891File:0010.jpg2021-01-07T02:06:22Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:0009.jpg&diff=53890File:0009.jpg2021-01-07T02:06:01Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:0008.jpg&diff=53889File:0008.jpg2021-01-07T02:05:19Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:0007.jpg&diff=53888File:0007.jpg2021-01-07T02:04:42Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:0006.jpg&diff=53887File:0006.jpg2021-01-07T02:04:09Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:0005.jpg&diff=53886File:0005.jpg2021-01-07T02:03:09Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:0004.jpg&diff=53885File:0004.jpg2021-01-07T02:02:32Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:0003.jpg&diff=53884File:0003.jpg2021-01-07T02:02:10Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:0002.jpg&diff=53883File:0002.jpg2021-01-07T02:01:44Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Paper&diff=53882Paper2021-01-07T02:00:54Z<p>Agus.nuryadi: Replaced content with " alt text"</p>
<hr />
<div><br />
[[File:0001.jpg|1000px|thumb|left|alt text]]</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:0001.jpg&diff=53881File:0001.jpg2021-01-07T02:00:34Z<p>Agus.nuryadi: alt text</p>
<hr />
<div>[[File:0001.jpg|1000px|thumb|left|alt text]]</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Paper&diff=53879Paper2021-01-07T01:55:20Z<p>Agus.nuryadi: </p>
<hr />
<div> '''The application of loop-seals for the catalyst transfer to the Riser on pilot-plant FCC applying gas-particle simulation using MMPIC method''' <br />
<br />
=='''Abstract'''==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement sliding valve as a regulator of the catalyst distribution to the Riser in a pilot-scale fluid catalytic cracking (FCC). Pilot-plant FCC is not possible to use a sliding valve because the pipe diameter is small and catalyst often clogged in the sliding valve wall. Therefore, the study depicts loop-seal as replacing the sliding valve for the control catalyst to the Riser. Furthermore, the paper describes particle catalyst distribution as employing loop-seal adopting the hydrodynamic approach with the Multiphase Particle-in-cell method (MP-PIC). This method applied three different drag models, the interphase drag model, Wen-Yu Drag Model, and Wen-Yu / Ergun Blend Drag Model, regarding the catalyst drops from the regenerator and the air blow to adjust the catalyst the Riser, which is the catalyst based on Region A 'Miyauchi. The result describes the difference in particle distribution using the three drag models.<br />
<br />
Keywords: Computational Fluid Dynamics, CFD-MPPIC, Loop-seal, catalyst, FCC.<br />
<br />
==1. Introduction==<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method (FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) is the numerical methods for predicting dense gas-solids flow. The gas-phase is treated as a continuum in the Eulerian reference frame. The solids are modelled in the Lagrangian reference frame tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows. The method employs a fixed Eulerian grid, and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the particles' interactions are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
'''1.1 Mathematical model MPPIC'''<br />
<br />
Mathematical models of separated particulate multiphase flow have used either a continuum approach for all phases [1, 2] or a continuum for the fluid and a Lagrangian model for particles [3]. The continuum–continuum model readily allows modeling of particle–particle stresses in dense particle flows using spatial gradients of particle volume fractions [2, 4]. However, modeling a distribution of types and sizes of particles complicates the continuum formulation because separate continuity and momentum equations must be solved for each size and type [4, 5]. Using a continuum model for the fluid phase and a Lagrangian model for the particle phase allows economical solution for flows with a wide range of particle types, sizes, shapes, and velocities [4, 6]. However, the collision frequency is high for volume fractions above 5% and cannot be realistically resolved by current Lagrangian collision calculations [6].<br />
<br />
Particle-in-cell (PIC) methods have been used since the 1960s [7]. Fluids are represented by discrete mass points. The differential conservation equations of mass, momentum, and energy govern the flow, although the conservation of mass is satisfied by the summation of mass points in a computational cell. Nontransport terms are calculated from the differential equations, and the transport terms are calculated from mass points moving by a velocity weighting procedure. The initial motivation for PIC methods was probably the accuracy in following interfaces.<br />
<br />
'''A. Continuum Phase.'''<br />
The continuity equation for the fluid with no interphase mass transfer is:<br />
<br />
[[File:1pic.JPG|800px|thumb|centre|alt text]]<br />
<br />
The fluid phase is incompressible and fluid and particle phases are isothermal. The momentum equation presented here neglects viscous molecular diffusion in the fluid but retains the viscous drag between particles and fluid through the interphase drag force, F. Neglecting the laminar fluid viscous terms generally has negligible effect on dense particle flow, and laminar terms can be easily included in the fluid equation set. The discrete particle to fluid momentum transfer (which is a turbulent closure model for subgrid momentum transfer between particles and fluid) generally produces low Reynolds numbers (based on particle diameter) and provides an excellent prediction of dense particle flows over a wide range of gas flow.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Paper&diff=53878Paper2021-01-07T01:54:51Z<p>Agus.nuryadi: </p>
<hr />
<div> '''The application of loop-seals for the catalyst transfer to the Riser on pilot-plant FCC applying gas-particle simulation using MMPIC method''' <br />
<br />
=='''Abstract'''==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement sliding valve as a regulator of the catalyst distribution to the Riser in a pilot-scale fluid catalytic cracking (FCC). Pilot-plant FCC is not possible to use a sliding valve because the pipe diameter is small and catalyst often clogged in the sliding valve wall. Therefore, the study depicts loop-seal as replacing the sliding valve for the control catalyst to the Riser. Furthermore, the paper describes particle catalyst distribution as employing loop-seal adopting the hydrodynamic approach with the Multiphase Particle-in-cell method (MP-PIC). This method applied three different drag models, the interphase drag model, Wen-Yu Drag Model, and Wen-Yu / Ergun Blend Drag Model, regarding the catalyst drops from the regenerator and the air blow to adjust the catalyst the Riser, which is the catalyst based on Region A 'Miyauchi. The result describes the difference in particle distribution using the three drag models.<br />
<br />
Keywords: Computational Fluid Dynamics, CFD-MPPIC, Loop-seal, catalyst, FCC.<br />
<br />
==1. Introduction==<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method (FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) is the numerical methods for predicting dense gas-solids flow. The gas-phase is treated as a continuum in the Eulerian reference frame. The solids are modelled in the Lagrangian reference frame tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows. The method employs a fixed Eulerian grid, and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the particles' interactions are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
'''1.1 Mathematical model MPPIC'''<br />
<br />
Mathematical models of separated particulate multiphase flow have used either a continuum approach for all phases [1, 2] or a continuum for the fluid and a Lagrangian model for particles [3]. The continuum–continuum model readily allows modeling of particle–particle stresses in dense particle flows using spatial gradients of particle volume fractions [2, 4]. However, modeling a distribution of types and sizes of particles complicates the continuum formulation because separate continuity and momentum equations must be solved for each size and type [4, 5]. Using a continuum model for the fluid phase and a Lagrangian model for the particle phase allows economical solution for flows with a wide range of particle types, sizes, shapes, and velocities [4, 6]. However, the collision frequency is high for volume fractions above 5% and cannot be realistically resolved by current Lagrangian collision calculations [6].<br />
<br />
Particle-in-cell (PIC) methods have been used since the 1960s [7]. Fluids are represented by discrete mass points. The differential conservation equations of mass, momentum, and energy govern the flow, although the conservation of mass is satisfied by the summation of mass points in a computational cell. Nontransport terms are calculated from the differential equations, and the transport terms are calculated from mass points moving by a velocity weighting procedure. The initial motivation for PIC methods was probably the accuracy in following interfaces.<br />
<br />
'''A. Continuum Phase.'''<br />
The continuity equation for the fluid with no interphase mass transfer is:<br />
<br />
[[File:1pic.JPG|700px|thumb|centre|alt text]]<br />
<br />
The fluid phase is incompressible and fluid and particle phases are isothermal. The momentum equation presented here neglects viscous molecular diffusion in the fluid but retains the viscous drag between particles and fluid through the interphase drag force, F. Neglecting the laminar fluid viscous terms generally has negligible effect on dense particle flow, and laminar terms can be easily included in the fluid equation set. The discrete particle to fluid momentum transfer (which is a turbulent closure model for subgrid momentum transfer between particles and fluid) generally produces low Reynolds numbers (based on particle diameter) and provides an excellent prediction of dense particle flows over a wide range of gas flow.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:1pic.JPG&diff=53877File:1pic.JPG2021-01-07T01:54:03Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Paper&diff=53875Paper2021-01-07T01:52:07Z<p>Agus.nuryadi: Created page with " '''The application of loop-seals for the catalyst transfer to the Riser on pilot-plant FCC applying gas-particle simulation using MMPIC method''' =='''Abstract''..."</p>
<hr />
<div> '''The application of loop-seals for the catalyst transfer to the Riser on pilot-plant FCC applying gas-particle simulation using MMPIC method''' <br />
<br />
=='''Abstract'''==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement sliding valve as a regulator of the catalyst distribution to the Riser in a pilot-scale fluid catalytic cracking (FCC). Pilot-plant FCC is not possible to use a sliding valve because the pipe diameter is small and catalyst often clogged in the sliding valve wall. Therefore, the study depicts loop-seal as replacing the sliding valve for the control catalyst to the Riser. Furthermore, the paper describes particle catalyst distribution as employing loop-seal adopting the hydrodynamic approach with the Multiphase Particle-in-cell method (MP-PIC). This method applied three different drag models, the interphase drag model, Wen-Yu Drag Model, and Wen-Yu / Ergun Blend Drag Model, regarding the catalyst drops from the regenerator and the air blow to adjust the catalyst the Riser, which is the catalyst based on Region A 'Miyauchi. The result describes the difference in particle distribution using the three drag models.<br />
<br />
Keywords: Computational Fluid Dynamics, CFD-MPPIC, Loop-seal, catalyst, FCC.<br />
<br />
==1. Introduction==<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method (FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) is the numerical methods for predicting dense gas-solids flow. The gas-phase is treated as a continuum in the Eulerian reference frame. The solids are modelled in the Lagrangian reference frame tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows. The method employs a fixed Eulerian grid, and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the particles' interactions are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
'''1.1 Mathematical model MPPIC'''<br />
<br />
Mathematical models of separated particulate multiphase flow have used either a continuum approach for all phases [1, 2] or a continuum for the fluid and a Lagrangian model for particles [3]. The continuum–continuum model readily allows modeling of particle–particle stresses in dense particle flows using spatial gradients of particle volume fractions [2, 4]. However, modeling a distribution of types and sizes of particles complicates the continuum formulation because separate continuity and momentum equations must be solved for each size and type [4, 5]. Using a continuum model for the fluid phase and a Lagrangian model for the particle phase allows economical solution for flows with a wide range of particle types, sizes, shapes, and velocities [4, 6]. However, the collision frequency is high for volume fractions above 5% and cannot be realistically resolved by current Lagrangian collision calculations [6].<br />
<br />
Particle-in-cell (PIC) methods have been used since the 1960s [7]. Fluids are represented by discrete mass points. The differential conservation equations of mass, momentum, and energy govern the flow, although the conservation of mass is satisfied by the summation of mass points in a computational cell. Nontransport terms are calculated from the differential equations, and the transport terms are calculated from mass points moving by a velocity weighting procedure. The initial motivation for PIC methods was probably the accuracy in following interfaces.<br />
<br />
'''A. Continuum Phase.'''<br />
The continuity equation for the fluid with no interphase mass transfer is:</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Agus_Nuryadi&diff=53873Agus Nuryadi2021-01-07T01:48:21Z<p>Agus.nuryadi: </p>
<hr />
<div>[[File:Agusnuryadi.jpeg|200px|thumb|right|Agus.nuryadi]]<br />
<br />
== Kuliah Aplikasi CFD ==<br />
<br />
[[Persamaan atur]]<br />
<br />
[[Six degrees of freedom]]<br />
<br />
[[Hopper PLTU]]<br />
<br />
[[Cyclone]]<br />
<br />
[[Paper]]</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Agus_Nuryadi&diff=53872Agus Nuryadi2021-01-07T01:47:47Z<p>Agus.nuryadi: </p>
<hr />
<div>[[File:Agusnuryadi.jpeg|200px|thumb|right|Agus.nuryadi]]<br />
<br />
== Kuliah Aplikasi CFD ==<br />
<br />
[[Persamaan atur]]<br />
<br />
[[Six degrees of freedom]]<br />
<br />
[[Hopper PLTU]]<br />
<br />
[[Cyclone]]<br />
<br />
[[Tugas Besar]]</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Paper_for_UAS&diff=50972Paper for UAS2021-01-01T07:33:19Z<p>Agus.nuryadi: Blanked the page</p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Paper_for_UAS&diff=50971Paper for UAS2021-01-01T07:33:03Z<p>Agus.nuryadi: </p>
<hr />
<div>[[Synopsis]]</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Paper_for_UAS&diff=50801Paper for UAS2020-12-28T07:09:59Z<p>Agus.nuryadi: </p>
<hr />
<div>[[Synopsis]]<br />
<br />
[[ Research Question ]]<br />
<br />
[[ Draft1 ]]</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50796FInal-Draft2020-12-28T06:02:58Z<p>Agus.nuryadi: /* 2. Simulation conditions */</p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
=='''Abstract'''==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is loop-seal pipe by flowing the air below to regulate the catalyst and solve the Riser nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
=='''1. Introduction'''==<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) is one of the numerical methods for predicting dense gas-solids flow. The gas-phase is treated as a continuum in the Eulerian reference frame. The solids are modelled in the Lagrangian reference frame tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows. The method employs a fixed Eulerian grid, and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the particles' interactions are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
''Mathematical model MPPIC''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
''Conservation of Mass''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the statistical particle weight, Wp, and considering its mass change, dm/dt, under a chemical effects reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Rpn is the production/consumption rate of the n th chemical species, and Np is the number of chemical species. Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
''Conservation of Species Mass''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Xpn is the n th chemical species mass fraction, and Rpn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
''Conservation of Translational Momentum''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃g i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section Interparticle Stress below.<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where E cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation. B is a practical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
''Conservation of Internal Energy''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is present in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Cp and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction or phase change (h pn is the n the species-specific enthalpy). The last term, S p is a general source term. By using the MMPIC approaches can explain the process phenomena on the catalyst. A sliding valve controls transferring the catalyst from the regenerator to the riser in FCC plant. However, on FCC pilot-plant with a transfer pipe diameter, only 2 inches is impossible to use a sliding valve. The valve gets stuck during the opening and closing process to adjust the volume of the catalyst to the riser and the abrasion properties of the gas and catalyst that make the valve easily damaged. For this reason, this study describes the application of seal loops to regulate catalysts on a pilot plant scale FCC.<br />
<br />
=='''2. Simulation conditions'''==<br />
<br />
Transferring the catalyst from the regenerator to the riser is one of the crucial steps in the fluid catalytic cracking(FCC) process. Because the catalyst and crude oil (RPDPO) ratio determine the product's quality, the catalyst supply process must be considered, especially on the pilot-plant scale FCC plan. Figure 1 shows the FCC process diagram, in which in this paper, the sliding valve will be replaced with a loop-seal for pilot-plant scale FCC.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50795FInal-Draft2020-12-28T05:48:49Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
=='''Abstract'''==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is loop-seal pipe by flowing the air below to regulate the catalyst and solve the Riser nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
=='''1. Introduction'''==<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) is one of the numerical methods for predicting dense gas-solids flow. The gas-phase is treated as a continuum in the Eulerian reference frame. The solids are modelled in the Lagrangian reference frame tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows. The method employs a fixed Eulerian grid, and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the particles' interactions are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
''Mathematical model MPPIC''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
''Conservation of Mass''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the statistical particle weight, Wp, and considering its mass change, dm/dt, under a chemical effects reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Rpn is the production/consumption rate of the n th chemical species, and Np is the number of chemical species. Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
''Conservation of Species Mass''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Xpn is the n th chemical species mass fraction, and Rpn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
''Conservation of Translational Momentum''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃g i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section Interparticle Stress below.<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where E cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation. B is a practical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
''Conservation of Internal Energy''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is present in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Cp and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction or phase change (h pn is the n the species-specific enthalpy). The last term, S p is a general source term. By using the MMPIC approaches can explain the process phenomena on the catalyst. A sliding valve controls transferring the catalyst from the regenerator to the riser in FCC plant. However, on FCC pilot-plant with a transfer pipe diameter, only 2 inches is impossible to use a sliding valve. The valve gets stuck during the opening and closing process to adjust the volume of the catalyst to the riser and the abrasion properties of the gas and catalyst that make the valve easily damaged. For this reason, this study describes the application of seal loops to regulate catalysts on a pilot plant scale FCC.<br />
<br />
=='''2. Simulation conditions'''==</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50794FInal-Draft2020-12-28T05:48:18Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is loop-seal pipe by flowing the air below to regulate the catalyst and solve the Riser nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
=='''1. Introduction'''==<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) is one of the numerical methods for predicting dense gas-solids flow. The gas-phase is treated as a continuum in the Eulerian reference frame. The solids are modelled in the Lagrangian reference frame tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows. The method employs a fixed Eulerian grid, and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the particles' interactions are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
''Mathematical model MPPIC''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
''Conservation of Mass''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the statistical particle weight, Wp, and considering its mass change, dm/dt, under a chemical effects reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Rpn is the production/consumption rate of the n th chemical species, and Np is the number of chemical species. Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
''Conservation of Species Mass''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Xpn is the n th chemical species mass fraction, and Rpn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
''Conservation of Translational Momentum''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃g i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section Interparticle Stress below.<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where E cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation. B is a practical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
''Conservation of Internal Energy''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is present in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Cp and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction or phase change (h pn is the n the species-specific enthalpy). The last term, S p is a general source term. By using the MMPIC approaches can explain the process phenomena on the catalyst. A sliding valve controls transferring the catalyst from the regenerator to the riser in FCC plant. However, on FCC pilot-plant with a transfer pipe diameter, only 2 inches is impossible to use a sliding valve. The valve gets stuck during the opening and closing process to adjust the volume of the catalyst to the riser and the abrasion properties of the gas and catalyst that make the valve easily damaged. For this reason, this study describes the application of seal loops to regulate catalysts on a pilot plant scale FCC.<br />
<br />
=='''2. Simulation conditions'''==</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50793FInal-Draft2020-12-28T05:45:39Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is loop-seal pipe by flowing the air below to regulate the catalyst and solve the Riser nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
'''1. Introduction'''<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) is one of the numerical methods for predicting dense gas-solids flow. The gas-phase is treated as a continuum in the Eulerian reference frame. The solids are modelled in the Lagrangian reference frame tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows. The method employs a fixed Eulerian grid, and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the particles' interactions are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
''Mathematical model MPPIC''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
''Conservation of Mass''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the statistical particle weight, Wp, and considering its mass change, dm/dt, under a chemical effects reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Rpn is the production/consumption rate of the n th chemical species, and Np is the number of chemical species. Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
''Conservation of Species Mass''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Xpn is the n th chemical species mass fraction, and Rpn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
''Conservation of Translational Momentum''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃g i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section Interparticle Stress below.<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where E cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation. B is a practical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
''Conservation of Internal Energy''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is present in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Cp and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction or phase change (h pn is the n the species-specific enthalpy). The last term, S p is a general source term. By using the MMPIC approaches can explain the process phenomena on the catalyst. A sliding valve controls transferring the catalyst from the regenerator to the riser in FCC plant. However, on FCC pilot-plant with a transfer pipe diameter, only 2 inches is impossible to use a sliding valve. The valve gets stuck during the opening and closing process to adjust the volume of the catalyst to the riser and the abrasion properties of the gas and catalyst that make the valve easily damaged. For this reason, this study describes the application of seal loops to regulate catalysts on a pilot plant scale FCC.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50792FInal-Draft2020-12-28T05:35:23Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is loop-seal pipe by flowing the air below to regulate the catalyst and solve the Riser nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
'''1. Introduction'''<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) is one of the numerical methods for predicting dense gas-solids flow. The gas-phase is treated as a continuum in the Eulerian reference frame. The solids are modelled in the Lagrangian reference frame tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows. The method employs a fixed Eulerian grid, and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the particles' interactions are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
''Mathematical model MPPIC''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
''Conservation of Mass''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the statistical particle weight, Wp, and considering its mass change, dm/dt, under a chemical effects reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Rpn is the production/consumption rate of the n th chemical species, and Np is the number of chemical species. Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
''Conservation of Species Mass''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Xpn is the n th chemical species mass fraction, and Rpn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
''Conservation of Translational Momentum''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃g i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section Interparticle Stress below.<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where E cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation. B is a practical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
''Conservation of Internal Energy''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is present in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Cp and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction or phase change (h pn is the n the species-specific enthalpy). The last term, S p is a general source term.<br />
<br />
By using the MMPIC approaches can explain the process phenomena on the catalyst. A sliding valve controls transferring the catalyst from the regenerator to the riser in FCC plant. However, on FCC pilot-plant with a transfer pipe diameter, only 2 inches is impossible to use a sliding valve. The valve gets stuck during the opening and closing process to adjust the volume of the catalyst to the riser and the abrasion properties of the gas and catalyst that make the valve easily damaged. For this reason, this study describes the application of seal loops to regulate catalysts on a pilot plant scale FCC.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50791FInal-Draft2020-12-28T05:30:29Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is loop-seal pipe by flowing the air below to regulate the catalyst and solve the Riser nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
'''1. Introduction'''<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) is one of the numerical methods for predicting dense gas-solids flow. The gas-phase is treated as a continuum in the Eulerian reference frame. The solids are modelled in the Lagrangian reference frame tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows. The method employs a fixed Eulerian grid, and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the particles' interactions are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
''Mathematical model MPPIC''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
<br />
<br />
''Conservation of Mass''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the statistical particle weight, Wp, and considering its mass change, dm/dt, under a chemical effects reaction.<br />
<br />
eq<br />
<br />
Rpn is the production/consumption rate of the n th chemical species, and Np is the number of chemical species. Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
''Conservation of Species Mass''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
Xpn is the n th chemical species mass fraction, and Rpn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
Conservation of Translational Momentum<br />
The general conservation of translation momentum for the p th MMPIC parcel in i th coordinate direction is given by:<br />
<br />
where ܷU i is the parcel velocity, and ݃g i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section Interparticle Stress below.<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
where E cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation. B is a practical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
''Conservation of Internal Energy''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is present in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
where Cp and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction or phase change (h pn is the n the species-specific enthalpy). The last term, S p is a general source term.<br />
<br />
By using the MMPIC approaches can explain the process phenomena on the catalyst. A sliding valve controls transferring the catalyst from the regenerator to the riser in FCC plant. However, on FCC pilot-plant with a transfer pipe diameter, only 2 inches is impossible to use a sliding valve. The valve gets stuck during the opening and closing process to adjust the volume of the catalyst to the riser and the abrasion properties of the gas and catalyst that make the valve easily damaged. For this reason, this study describes the application of seal loops to regulate catalysts on a pilot plant scale FCC.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50790FInal-Draft2020-12-28T03:12:04Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is loop-seal pipe by flowing the air below to regulate the catalyst and solve the Riser nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
'''1. Introduction'''<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) is one of the numerical methods for predicting dense gas-solids flow. The gas-phase is treated as a continuum in the Eulerian reference frame. The solids are modelled in the Lagrangian reference frame tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows. The method employs a fixed Eulerian grid, and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the particles' interactions are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50785FInal-Draft2020-12-28T02:23:36Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is loop-seal pipe by flowing the air below to regulate the catalyst and solve the Riser nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
'''1. Introduction'''<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is the best an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50784FInal-Draft2020-12-28T02:15:22Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is loop-seal pipe by flowing the air below to regulate the catalyst and solve the Riser nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
'''1. Introduction'''<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.<br />
<br />
Hydrodynamics through the Computational Fluid Dynamics (CFD) depicts the phenomenon of catalysts in the FCC. There are several types of gas and particle simulation approaches Eulerian, MPPIC, and DEM. Each type of method has its characteristics in solving gas-particle problems. MPPIC is an approach with the parcel in cell where the solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). Different diameter particles of the same material must be defined as separate solid phases in the present formulation, each with its statistical classification. This paper applies CFDSOF as a tool to calculate the catalyst phenomenon in the FCC.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50783FInal-Draft2020-12-28T02:10:59Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is loop-seal pipe by flowing the air below to regulate the catalyst and solve the Riser nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
'''1. Introduction'''<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50782FInal-Draft2020-12-28T02:08:56Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is chiffon or layered U pipe by flowing the air below to regulate the catalyst and solve the Riser's nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
'''1. Introduction'''<br />
<br />
During 2019 Indonesia reached 51.8 million tons of CPO. From this source, it is processed into green fuel. Before becoming Green Fuel, CPO is processed first to become Refined Bleached Deodorized Palm Oil (RBDPO) next processed utilising the Fluid Catalytic Cracking method ( FCC). The FCC unit process consists of the feed injection system, Riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. The main processing products for RBDPO using the FCC are Gasoline, LCO (light cycle oil) and LPG.<br />
<br />
The FCC process is a hydrocarbon reaction between crude oil (RBDPO) and a catalyst based on Particles' Geldart Classification. The proper selection of catalyst is essential to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earth content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator and Riser are equipment that determines the FCC's product yield. This paper describes the transport of catalysts from the regenerator to the Riser.</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50781FInal-Draft2020-12-28T02:01:27Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows using of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is chiffon or layered U pipe by flowing the air below to regulate the catalyst and solve the Riser's nitrogen leakage. This study uses the CFD approach, specifically the MMPIC applying CFDSOF, including the preliminary validation with catalyst dimension based on the Geldart group A and A ' Miyauchi.<br />
<br />
<br />
'''Introduction'''</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50780FInal-Draft2020-12-28T01:58:11Z<p>Agus.nuryadi: </p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
<br />
<br />
'''Abstract'''</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=FInal-Draft&diff=50779FInal-Draft2020-12-28T01:57:55Z<p>Agus.nuryadi: Created page with "'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation ''' '''Abstract'''"</p>
<hr />
<div>'''The application of loop-seals for the catalyst transfer from the Regenerator to the Riser on pilot-plant scale FCC applying gas-particle simulation<br />
'''<br />
<br />
'''Abstract'''</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Paper_for_UAS&diff=50778Paper for UAS2020-12-28T01:55:58Z<p>Agus.nuryadi: </p>
<hr />
<div>[[Synopsis]]<br />
<br />
[[ Research Question ]]<br />
<br />
[[ Draft1 ]]<br />
<br />
[[ FInal-Draft]]</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Draft1&diff=50338Draft12020-12-22T08:41:25Z<p>Agus.nuryadi: </p>
<hr />
<div>'''penngunaan loop-seal pada proses transfer katalis dari regenerator ke riser pada FCC skala pilotplant dengan menggunakan simulasi gas-particle<br />
'''<br />
==abstract==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows to use of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is chiffon or layered U pipe by flowing the air below to regulate the catalyst and solve the Riser's nitrogen leakage. This study uses the CFD approach, specifically the MMPIC and DEM models, including the preliminary validation with catalyst dimension based on the Geldart group '''A''' and '''A '''' Miyauchi.<br />
<br />
==Introduction==<br />
<br />
Indonesia sepanjang 2019 mencapai 51,8 juta ton CPO, dari sumber tersebut dapat di olah menjadi green fuel, sebelum menjadi Green Fuel, CPO di olah dahulu menjadi Bleached and Deodorized Palm Oil (RBDPO) 100% kemudian di proses dengan metode Fluid Catalytic Cracking (FCC). The process of the FCC unit consists of the feed injection system, riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. Product pengolahan RBDPO dengan menggunakkan FCC yang utama adalah Gasoline, LCO (light cycle oil) dan LPG.<br />
<br />
Proses FCC adalah reaksi hydrocarbon antara crude oil (RBDPO) dengan catalyst, berdasarkan The Geldart Classification of Particles katalist pada FCC di golongkan pada group A dan Region A', Miyauchi menggolongkan katalis berdasarkan group A’ dengan properties diameter 50-70 Micron. The proper selection of catalyst is very important to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earths content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator dan riser adalah peralatan yang menentukan hasil product dari FCC sehingga pada paper ini menjelaskan transport katalis dari regenerator ke riser.<br />
<br />
Untuk mempelajari fenomena katalis pada FCC menggunakan hydrodynamics melalui pendekatan Computational Fluid Dynamics (CFD), pada pendekatan simulasi gas dan particle terdapat beberapa jenis metode yaitu, Eulerian, MPPIC, DEM. Setiap jenis metode memiliki karakteristik masing pada penyelesain masalah gas-particle, pada MPPIC adalah pendekatan dengan parcel in cell di mana solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). In the present formulation, different diameter particles of the same material must be defined as separate solid phases, each with its own statistical classification, pada paper ini mengnakan CFDSOF sebagai device untuk menghitung fenomena katalist pada FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) numerical method for predicting dense gas-solids flow. The MP-PIC method is a hybrid method such as IBM method, where the gas-phase is treated as a continuum in the Eulerian reference frame and the solids are modeled in the Lagrangian reference frame by tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows and the method employs a fixed Eulerian grid and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the interactions between the particles are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
[[File:1PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where X is particle position, ܷUm is particle velocity, ''p'' m is particle density, ܸ Vm is particle volume, and t is time. The subscript ݉m is indicative of nodding to solids phase ݉, which in this case would indicate a unique solids class of particles.<br />
<br />
[[File:2PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Here ∇ um is the divergence operator with respect to the velocity, ܷUm and A m is the discrete particle-phase acceleration. The particle distribution function integrated over velocity and mass will yield the likely number of particles per unit volume at the position, X, at time t, for small intervals of (Vm + dVm, ''p''m + dpm, Um + dUm). The solids volume fraction, ''E''s, can then by represented through the distribution function using a volume integral.<br />
<br />
[[File:3PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
The solids phase is coupled to the Eulerian governing equations through the interphase momentum transfer term. Allowing Igm to be the contribution due to interphase momentum transfer between the gas and the m th solid phase, Where Dm is drag coefficient and ∇ p is pressure gradient.<br />
<br />
[[File:4PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
'''1.1 Mathematical model MPPIC'''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
'''Conservation of Mass'''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the particle’s statistical weight, Wp, and considering its mass change, dm/dt, under the effects of a chemical reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where R pn is the rate of production/consumption of the n th chemical species, and Np is the number of chemical species. This is not unlike the conservation of mass equation defined in Musser and Carney (2020). Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
'''Conservation of Species Mass'''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Where X pn is the n th chemical species mass fraction, and R pn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
'''Conservation of Translational Momentum'''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in the i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃'''g''' i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section '''Interparticle Stress''' below.<br />
<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:9PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ''E'' cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation, and ''B'' is an empirical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
'''Conservation of Internal Energy'''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is presented in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where C p and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction and/or phase change (h pn is the n the species-specific enthalpy) The last term, S p is a general source term. Note that S p might represent particle-particle heat transfer (currently 0 in PIC; there is no conduction model), fluid-particle heat transfer (convection), or radiative heat transfer (currently 0 in PIC; radiation model is pending).<br />
<br />
Pada studi ini juga melalakukan pemodelan dengan menggunkan metode DEM, Pemodelan dengan Computational Fluid Dynamics (CFD) coupling dengan DEM (Discrete element method), In such an approach, the trajectories of and the forces acting on individual particles are tracked directly. It offers a sound theoretical base to generally model the interactions between particles as well as with the surrounding fluid and screen wall. This cannot be achieved by widely used continuum methods such as two-fluid models, which have not, to date, been applied to simulate particle screen. In recent years, the CFD-DEM approach has been widely accepted as an effective tool to study various particle-fluid systems, as reviewed by different investigators. Despite the broad applications, only a few efforts have been reported to use the CFD-DEM method to study particle retention. Recently, Shaffee et al. used a CFD-DEM model to study the effect of adhesion on particle filtration by a screen and demonstrated that an increase in particle adhesion reduces the porosity and pressure drop across the sand pack covering the screen. These CFD-DEM studies have demonstrated the feasibility of this method in modeling sand screen, to some degree. However, to date, CFD-DEM studies on the influences of slot width-particle size ratios and wetting fluids on screen retention performance have not been reported in the literature. Besides, none of the previous CFD-DEM studies have attempted to analyze particle-fluid flow characteristics and force structures to understand the screen retention performance and identify the underlying mechanisms.<br />
<br />
'''1.2 Mathematical model CFD-DEM'''<br />
<br />
The current CFD-DEM model is based on the model used to simulate hydraulic conveying. For brevity, only the key features of the model are outlined below. However, detailed modeling and numerical treatments can be found elsewhere. <br />
<br />
'''Particle motion'''<br />
<br />
In the DEM model, the translational and rotational motion of a particle is governed by Newton's second law of motion, formulated as follows:<br />
<br />
[[File:DEM1.JPG|400px|thumb|centre|alt text]]<br />
<br />
where mi is the particle mass, Ii is the moment of inertia, vi is the particle translational velocity, ωi is the particle angular velocity, and ki is the number of particle/wall in contact with particle i. The translational motion of a particle is caused by the particle-fluid interaction forces including the drag force, fd, i. The pressure gradient force, f∇p, i and the viscous force, f∇. τ, i, the gravitational force, mig and the inter-particle contact forces such as the elastic force, fc, ij and the viscous damping force, fd, ij. The rotational motion is caused by the inter-particle contact forces due to particle/wall j which generate torques, Tij causing particle I to rotate. The particle motions are calculated based on a soft-sphere contact model proposed originally by Cundall and Strack, and the inter-particle contact forces are calculated according to the Hertzian contact theory. The equations used to calculate the interparticle contact forces and particle-fluid interaction forces involved in Eq. 1 are listed in Table 1.<br />
<br />
'''Fluid flow'''<br />
<br />
In the CFD model, the fluid flow is modeled in a similar way as those in the two-fluid model in the form of model A, in which the pressure is shared by both the liquid and solid phases [29,36]. The governing equations include the continuity equation and the Navier-Stokes equations:<br />
<br />
[[File:DEM2.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ρf is the fluid density, uf is the fluid velocity and p is the pressure, τ is the divergence of stress tensor that includes viscous and Reynolds<br />
<br />
Table 1<br />
The contact forces and particle-fluid interaction forces considered in the current model.<br />
<br />
[[File:DEM3.JPG|400px|thumb|centre|alt text]]<br />
<br />
Dengan menggunakan pendekatan MMPIC dan DEM mampu menjelaskan proses fenomena pada katalis. Pada skala besar FCC proses transfer katalis dari regenerator ke riser di atur oleh sliding valve atau dengan pluge valve dapat di lihat pada gambar di bawah. Akan tetapi pada skala pilot plant dengan diameter pipa transfer adalah 2 inch tidak di munggkinkan dengan menggunakan sliding valve karena sering terjadi stuck pada saat proses buka dan tutup untuk mengatur volume katalis menuju riser, selaintu sifat abrasi dari gas dan katalis memudahkan valve mudah rusak. Untuk itu dalam studi ini menjelaskan aplikasi seal loop untuk mengatur katalis pada FCC skala pilot plant. <br />
<br />
[[File:FCC_Pic.gif|1000px|thumb|centre|alt text]]<br />
<br />
The subject plan on this paper is a Replacement valve<br />
<br />
Pada gambar di bawah ini menjelaskan geometry pada loop-seal untuk mengatur laju aliran massa katalis ke riser. Dengan boundary kondisi batas katalis jatuh dari regenerator kemudian memenuhi loop-seal sampai ketinggian yang di tentukan kemudian air mendorong masuk dari sisi bawah untuk mengatur katalis keluar menuju riser. Pada gambar di bawah ini juga menjelaskan bahwa geometri pada saat pembentukan mesh pada CFDSOF di bagi menjadi 5 body dimana untuk mempermudah saat pembentukan mesh yang baik.<br />
<br />
[[File:intro1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
<br />
Hasil simulasi dengan PIC-CFDSOF dengan 1000 parcell di dapat sebagai berikut<br />
<br />
[[File:PIC1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
[[File:PIC2.JPG|1000px|thumb|centre|alt text]]<br />
<br />
Hasil simulasi dengan DEM-MFIX dengan 1000 parcell di dapat sebagai berikut:<br />
<br />
[[File:DEM-1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
[[File:DEM-2.JPG|1000px|thumb|centre|alt text]]<br />
<br />
Pada simulasi diatas masih menggunakan diameter particle 0.0001 mm belum menggunkaan katalis 50-70 micron<br />
<br />
==Simulation conditions==</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Draft1&diff=50336Draft12020-12-22T08:22:51Z<p>Agus.nuryadi: </p>
<hr />
<div>'''penngunaan loop-seal pada proses transfer kalalis dari regenerator ke riser pada FCC skala pilotplant dengan menggunakan simulasi gas-particle<br />
'''<br />
==abstract==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows to use of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is chiffon or layered U pipe by flowing the air below to regulate the catalyst and solve the Riser's nitrogen leakage. This study uses the CFD approach, specifically the MMPIC and DEM models, including the preliminary validation with catalyst dimension based on the Geldart group '''A''' and '''A '''' Miyauchi.<br />
<br />
==Introduction==<br />
<br />
Indonesia sepanjang 2019 mencapai 51,8 juta ton CPO, dari sumber tersebut dapat di olah menjadi green fuel, sebelum menjadi Green Fuel, CPO di olah dahulu menjadi Bleached and Deodorized Palm Oil (RBDPO) 100% kemudian di proses dengan metode Fluid Catalytic Cracking (FCC). The process of the FCC unit consists of the feed injection system, riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. Product pengolahan RBDPO dengan menggunakkan FCC yang utama adalah Gasoline, LCO (light cycle oil) dan LPG.<br />
<br />
Proses FCC adalah reaksi hydrocarbon antara crude oil (RBDPO) dengan catalyst, berdasarkan The Geldart Classification of Particles katalist pada FCC di golongkan pada group A dan Region A', Miyauchi menggolongkan katalis berdasarkan group A’ dengan properties diameter 50-70 Micron. The proper selection of catalyst is very important to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earths content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator dan riser adalah peralatan yang menentukan hasil product dari FCC sehingga pada paper ini menjelaskan transport katalis dari regenerator ke riser.<br />
<br />
Untuk mempelajari fenomena katalis pada FCC menggunakan hydrodynamics melalui pendekatan Computational Fluid Dynamics (CFD), pada pendekatan simulasi gas dan particle terdapat beberapa jenis metode yaitu, Eulerian, MPPIC, DEM. Setiap jenis metode memiliki karakteristik masing pada penyelesain masalah gas-particle, pada MPPIC adalah pendekatan dengan parcel in cell di mana solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). In the present formulation, different diameter particles of the same material must be defined as separate solid phases, each with its own statistical classification, pada paper ini mengnakan CFDSOF sebagai device untuk menghitung fenomena katalist pada FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) numerical method for predicting dense gas-solids flow. The MP-PIC method is a hybrid method such as IBM method, where the gas-phase is treated as a continuum in the Eulerian reference frame and the solids are modeled in the Lagrangian reference frame by tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows and the method employs a fixed Eulerian grid and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the interactions between the particles are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
[[File:1PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where X is particle position, ܷUm is particle velocity, ''p'' m is particle density, ܸ Vm is particle volume, and t is time. The subscript ݉m is indicative of nodding to solids phase ݉, which in this case would indicate a unique solids class of particles.<br />
<br />
[[File:2PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Here ∇ um is the divergence operator with respect to the velocity, ܷUm and A m is the discrete particle-phase acceleration. The particle distribution function integrated over velocity and mass will yield the likely number of particles per unit volume at the position, X, at time t, for small intervals of (Vm + dVm, ''p''m + dpm, Um + dUm). The solids volume fraction, ''E''s, can then by represented through the distribution function using a volume integral.<br />
<br />
[[File:3PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
The solids phase is coupled to the Eulerian governing equations through the interphase momentum transfer term. Allowing Igm to be the contribution due to interphase momentum transfer between the gas and the m th solid phase, Where Dm is drag coefficient and ∇ p is pressure gradient.<br />
<br />
[[File:4PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
'''1.1 Mathematical model MPPIC'''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
'''Conservation of Mass'''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the particle’s statistical weight, Wp, and considering its mass change, dm/dt, under the effects of a chemical reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where R pn is the rate of production/consumption of the n th chemical species, and Np is the number of chemical species. This is not unlike the conservation of mass equation defined in Musser and Carney (2020). Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
'''Conservation of Species Mass'''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Where X pn is the n th chemical species mass fraction, and R pn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
'''Conservation of Translational Momentum'''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in the i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃'''g''' i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section '''Interparticle Stress''' below.<br />
<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:9PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ''E'' cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation, and ''B'' is an empirical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
'''Conservation of Internal Energy'''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is presented in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where C p and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction and/or phase change (h pn is the n the species-specific enthalpy) The last term, S p is a general source term. Note that S p might represent particle-particle heat transfer (currently 0 in PIC; there is no conduction model), fluid-particle heat transfer (convection), or radiative heat transfer (currently 0 in PIC; radiation model is pending).<br />
<br />
Pada studi ini juga melalakukan pemodelan dengan menggunkan metode DEM, Pemodelan dengan Computational Fluid Dynamics (CFD) coupling dengan DEM (Discrete element method), In such an approach, the trajectories of and the forces acting on individual particles are tracked directly. It offers a sound theoretical base to generally model the interactions between particles as well as with the surrounding fluid and screen wall. This cannot be achieved by widely used continuum methods such as two-fluid models, which have not, to date, been applied to simulate particle screen. In recent years, the CFD-DEM approach has been widely accepted as an effective tool to study various particle-fluid systems, as reviewed by different investigators. Despite the broad applications, only a few efforts have been reported to use the CFD-DEM method to study particle retention. Recently, Shaffee et al. used a CFD-DEM model to study the effect of adhesion on particle filtration by a screen and demonstrated that an increase in particle adhesion reduces the porosity and pressure drop across the sand pack covering the screen. These CFD-DEM studies have demonstrated the feasibility of this method in modeling sand screen, to some degree. However, to date, CFD-DEM studies on the influences of slot width-particle size ratios and wetting fluids on screen retention performance have not been reported in the literature. Besides, none of the previous CFD-DEM studies have attempted to analyze particle-fluid flow characteristics and force structures to understand the screen retention performance and identify the underlying mechanisms.<br />
<br />
'''1.2 Mathematical model CFD-DEM'''<br />
<br />
The current CFD-DEM model is based on the model used to simulate hydraulic conveying. For brevity, only the key features of the model are outlined below. However, detailed modeling and numerical treatments can be found elsewhere. <br />
<br />
'''Particle motion'''<br />
<br />
In the DEM model, the translational and rotational motion of a particle is governed by Newton's second law of motion, formulated as follows:<br />
<br />
[[File:DEM1.JPG|400px|thumb|centre|alt text]]<br />
<br />
where mi is the particle mass, Ii is the moment of inertia, vi is the particle translational velocity, ωi is the particle angular velocity, and ki is the number of particle/wall in contact with particle i. The translational motion of a particle is caused by the particle-fluid interaction forces including the drag force, fd, i. The pressure gradient force, f∇p, i and the viscous force, f∇. τ, i, the gravitational force, mig and the inter-particle contact forces such as the elastic force, fc, ij and the viscous damping force, fd, ij. The rotational motion is caused by the inter-particle contact forces due to particle/wall j which generate torques, Tij causing particle I to rotate. The particle motions are calculated based on a soft-sphere contact model proposed originally by Cundall and Strack, and the inter-particle contact forces are calculated according to the Hertzian contact theory. The equations used to calculate the interparticle contact forces and particle-fluid interaction forces involved in Eq. 1 are listed in Table 1.<br />
<br />
'''Fluid flow'''<br />
<br />
In the CFD model, the fluid flow is modeled in a similar way as those in the two-fluid model in the form of model A, in which the pressure is shared by both the liquid and solid phases [29,36]. The governing equations include the continuity equation and the Navier-Stokes equations:<br />
<br />
[[File:DEM2.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ρf is the fluid density, uf is the fluid velocity and p is the pressure, τ is the divergence of stress tensor that includes viscous and Reynolds<br />
<br />
Table 1<br />
The contact forces and particle-fluid interaction forces considered in the current model.<br />
<br />
[[File:DEM3.JPG|400px|thumb|centre|alt text]]<br />
<br />
Dengan menggunakan pendekatan MMPIC dan DEM mampu menjelaskan proses fenomena pada katalis. Pada skala besar FCC proses transfer katalis dari regenerator ke riser di atur oleh sliding valve atau dengan pluge valve dapat di lihat pada gambar di bawah. Akan tetapi pada skala pilot plant dengan diameter pipa transfer adalah 2 inch tidak di munggkinkan dengan menggunakan sliding valve karena sering terjadi stuck pada saat proses buka dan tutup untuk mengatur volume katalis menuju riser, selaintu sifat abrasi dari gas dan katalis memudahkan valve mudah rusak. Untuk itu dalam studi ini menjelaskan aplikasi seal loop untuk mengatur katalis pada FCC skala pilot plant. <br />
<br />
[[File:FCC_Pic.gif|1000px|thumb|centre|alt text]]<br />
<br />
The subject plan on this paper is a Replacement valve<br />
<br />
Pada gambar di bawah ini menjelaskan geometry pada loop-seal untuk mengatur laju aliran massa katalis ke riser. Dengan boundary kondisi batas katalis jatuh dari regenerator kemudian memenuhi loop-seal sampai ketinggian yang di tentukan kemudian air mendorong masuk dari sisi bawah untuk mengatur katalis keluar menuju riser. Pada gambar di bawah ini juga menjelaskan bahwa geometri pada saat pembentukan mesh pada CFDSOF di bagi menjadi 5 body dimana untuk mempermudah saat pembentukan mesh yang baik.<br />
<br />
[[File:intro1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
<br />
Hasil simulasi dengan PIC-CFDSOF dengan 1000 parcell di dapat sebagai berikut<br />
<br />
[[File:PIC1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
[[File:PIC2.JPG|1000px|thumb|centre|alt text]]<br />
<br />
Hasil simulasi dengan DEM-MFIX dengan 1000 parcell di dapat sebagai berikut:<br />
<br />
[[File:DEM-1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
[[File:DEM-2.JPG|1000px|thumb|centre|alt text]]<br />
<br />
Pada simulasi diatas masih menggunakan diameter particle 0.0001 mm belum menggunkaan katalis 50-70 micron<br />
<br />
==Simulation conditions==</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Draft1&diff=50334Draft12020-12-22T07:48:15Z<p>Agus.nuryadi: /* Introduction */</p>
<hr />
<div>'''penngunaan loop-seal pada proses transfer kalalis dari regenerator ke riser pada FCC skala pilotplant dengan menggunakan simulasi gas-particle<br />
'''<br />
==abstract==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows to use of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is chiffon or layered U pipe by flowing the air below to regulate the catalyst and solve the Riser's nitrogen leakage. This study uses the CFD approach, specifically the MMPIC and DEM models, including the preliminary validation with catalyst dimension based on the Geldart group '''A''' and '''A '''' Miyauchi.<br />
<br />
==Introduction==<br />
<br />
Indonesia sepanjang 2019 mencapai 51,8 juta ton CPO, dari sumber tersebut dapat di olah menjadi green fuel, sebelum menjadi Green Fuel, CPO di olah dahulu menjadi Bleached and Deodorized Palm Oil (RBDPO) 100% kemudian di proses dengan metode Fluid Catalytic Cracking (FCC). The process of the FCC unit consists of the feed injection system, riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. Product pengolahan RBDPO dengan menggunakkan FCC yang utama adalah Gasoline, LCO (light cycle oil) dan LPG.<br />
<br />
Proses FCC adalah reaksi hydrocarbon antara crude oil (RBDPO) dengan catalyst, berdasarkan The Geldart Classification of Particles katalist pada FCC di golongkan pada group A dan Region A', Miyauchi menggolongkan katalis berdasarkan group A’ dengan properties diameter 50-70 Micron. The proper selection of catalyst is very important to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earths content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator dan riser adalah peralatan yang menentukan hasil product dari FCC sehingga pada paper ini menjelaskan transport katalis dari regenerator ke riser.<br />
<br />
Untuk mempelajari fenomena katalis pada FCC menggunakan hydrodynamics melalui pendekatan Computational Fluid Dynamics (CFD), pada pendekatan simulasi gas dan particle terdapat beberapa jenis metode yaitu, Eulerian, MPPIC, DEM. Setiap jenis metode memiliki karakteristik masing pada penyelesain masalah gas-particle, pada MPPIC adalah pendekatan dengan parcel in cell di mana solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). In the present formulation, different diameter particles of the same material must be defined as separate solid phases, each with its own statistical classification, pada paper ini mengnakan CFDSOFT sebagai device untuk menghitung fenomena katalist pada FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) numerical method for predicting dense gas-solids flow. The MP-PIC method is a hybrid method such as IBM method, where the gas-phase is treated as a continuum in the Eulerian reference frame and the solids are modeled in the Lagrangian reference frame by tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows and the method employs a fixed Eulerian grid and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the interactions between the particles are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
[[File:1PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where X is particle position, ܷUm is particle velocity, ''p'' m is particle density, ܸ Vm is particle volume, and t is time. The subscript ݉m is indicative of nodding to solids phase ݉, which in this case would indicate a unique solids class of particles.<br />
<br />
[[File:2PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Here ∇ um is the divergence operator with respect to the velocity, ܷUm and A m is the discrete particle-phase acceleration. The particle distribution function integrated over velocity and mass will yield the likely number of particles per unit volume at the position, X, at time t, for small intervals of (Vm + dVm, ''p''m + dpm, Um + dUm). The solids volume fraction, ''E''s, can then by represented through the distribution function using a volume integral.<br />
<br />
[[File:3PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
The solids phase is coupled to the Eulerian governing equations through the interphase momentum transfer term. Allowing Igm to be the contribution due to interphase momentum transfer between the gas and the m th solid phase, Where Dm is drag coefficient and ∇ p is pressure gradient.<br />
<br />
[[File:4PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
'''1.1 Mathematical model MPPIC'''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
'''Conservation of Mass'''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the particle’s statistical weight, Wp, and considering its mass change, dm/dt, under the effects of a chemical reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where R pn is the rate of production/consumption of the n th chemical species, and Np is the number of chemical species. This is not unlike the conservation of mass equation defined in Musser and Carney (2020). Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
'''Conservation of Species Mass'''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Where X pn is the n th chemical species mass fraction, and R pn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
'''Conservation of Translational Momentum'''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in the i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃'''g''' i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section '''Interparticle Stress''' below.<br />
<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:9PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ''E'' cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation, and ''B'' is an empirical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
'''Conservation of Internal Energy'''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is presented in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where C p and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction and/or phase change (h pn is the n the species-specific enthalpy) The last term, S p is a general source term. Note that S p might represent particle-particle heat transfer (currently 0 in PIC; there is no conduction model), fluid-particle heat transfer (convection), or radiative heat transfer (currently 0 in PIC; radiation model is pending).<br />
<br />
Pada studi ini juga melalakukan pemodelan dengan menggunkan metode DEM, Pemodelan dengan Computational Fluid Dynamics (CFD) coupling dengan DEM (Discrete element method), In such an approach, the trajectories of and the forces acting on individual particles are tracked directly. It offers a sound theoretical base to generally model the interactions between particles as well as with the surrounding fluid and screen wall. This cannot be achieved by widely used continuum methods such as two-fluid models, which have not, to date, been applied to simulate particle screen. In recent years, the CFD-DEM approach has been widely accepted as an effective tool to study various particle-fluid systems, as reviewed by different investigators. Despite the broad applications, only a few efforts have been reported to use the CFD-DEM method to study particle retention. Recently, Shaffee et al. used a CFD-DEM model to study the effect of adhesion on particle filtration by a screen and demonstrated that an increase in particle adhesion reduces the porosity and pressure drop across the sand pack covering the screen. These CFD-DEM studies have demonstrated the feasibility of this method in modeling sand screen, to some degree. However, to date, CFD-DEM studies on the influences of slot width-particle size ratios and wetting fluids on screen retention performance have not been reported in the literature. Besides, none of the previous CFD-DEM studies have attempted to analyze particle-fluid flow characteristics and force structures to understand the screen retention performance and identify the underlying mechanisms.<br />
<br />
'''1.2 Mathematical model CFD-DEM'''<br />
<br />
The current CFD-DEM model is based on the model used to simulate hydraulic conveying. For brevity, only the key features of the model are outlined below. However, detailed modeling and numerical treatments can be found elsewhere. <br />
<br />
'''Particle motion'''<br />
<br />
In the DEM model, the translational and rotational motion of a particle is governed by Newton's second law of motion, formulated as follows:<br />
<br />
[[File:DEM1.JPG|400px|thumb|centre|alt text]]<br />
<br />
where mi is the particle mass, Ii is the moment of inertia, vi is the particle translational velocity, ωi is the particle angular velocity, and ki is the number of particle/wall in contact with particle i. The translational motion of a particle is caused by the particle-fluid interaction forces including the drag force, fd, i. The pressure gradient force, f∇p, i and the viscous force, f∇. τ, i, the gravitational force, mig and the inter-particle contact forces such as the elastic force, fc, ij and the viscous damping force, fd, ij. The rotational motion is caused by the inter-particle contact forces due to particle/wall j which generate torques, Tij causing particle I to rotate. The particle motions are calculated based on a soft-sphere contact model proposed originally by Cundall and Strack, and the inter-particle contact forces are calculated according to the Hertzian contact theory. The equations used to calculate the interparticle contact forces and particle-fluid interaction forces involved in Eq. 1 are listed in Table 1.<br />
<br />
'''Fluid flow'''<br />
<br />
In the CFD model, the fluid flow is modeled in a similar way as those in the two-fluid model in the form of model A, in which the pressure is shared by both the liquid and solid phases [29,36]. The governing equations include the continuity equation and the Navier-Stokes equations:<br />
<br />
[[File:DEM2.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ρf is the fluid density, uf is the fluid velocity and p is the pressure, τ is the divergence of stress tensor that includes viscous and Reynolds<br />
<br />
Table 1<br />
The contact forces and particle-fluid interaction forces considered in the current model.<br />
<br />
[[File:DEM3.JPG|400px|thumb|centre|alt text]]<br />
<br />
Dengan menggunakan pendekatan MMPIC dan DEM mampu menjelaskan proses fenomena pada katalis. Pada skala besar FCC proses transfer katalis dari regenerator ke riser di atur oleh sliding valve atau dengan pluge valve dapat di lihat pada gambar di bawah. Akan tetapi pada skala pilot plant dengan diameter pipa transfer adalah 2 inch tidak di munggkinkan dengan menggunakan sliding valve karena sering terjadi stuck pada saat proses buka dan tutup untuk mengatur volume katalis menuju riser, selaintu sifat abrasi dari gas dan katalis memudahkan valve mudah rusak. Untuk itu dalam studi ini menjelaskan aplikasi seal loop untuk mengatur katalis pada FCC skala pilot plant. <br />
<br />
[[File:FCC_Pic.gif|1000px|thumb|centre|alt text]]<br />
<br />
The subject plan on this paper is a Replacement valve<br />
<br />
Pada gambar di bawah ini menjelaskan geometry pada loop-seal untuk mengatur laju aliran massa katalis ke riser. Dengan boundary kondisi batas katalis jatuh dari regenerator kemudian memenuhi loop-seal sampai ketinggian yang di tentukan kemudian air mendorong masuk dari sisi bawah untuk mengatur katalis keluar menuju riser. Pada gambar di bawah ini juga menjelaskan bahwa geometri pada saat pembentukan mesh pada CFDSOFT di bagi menjadi 5 body dimana untuk mempermudah saat pembentukan mesh yang baik.<br />
<br />
[[File:intro1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
<br />
Hasil simulasi dengan PIC-CFDSOFT dengan 1000 parcell di dapat sebagai berikut<br />
<br />
[[File:PIC1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
[[File:PIC2.JPG|1000px|thumb|centre|alt text]]<br />
<br />
Hasil simulasi dengan DEM-MFIX dengan 1000 parcell di dapat sebagai berikut:<br />
<br />
[[File:DEM-1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
[[File:DEM-2.JPG|1000px|thumb|centre|alt text]]<br />
<br />
Pada simulasi diatas masih menggunakan diameter particle 0.0001 mm belum menggunkaan katalis 50-70 micron<br />
<br />
==Simulation conditions==</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Draft1&diff=50326Draft12020-12-22T07:34:38Z<p>Agus.nuryadi: /* Introduction */</p>
<hr />
<div>'''penngunaan loop-seal pada proses transfer kalalis dari regenerator ke riser pada FCC skala pilotplant dengan menggunakan simulasi gas-particle<br />
'''<br />
==abstract==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows to use of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is chiffon or layered U pipe by flowing the air below to regulate the catalyst and solve the Riser's nitrogen leakage. This study uses the CFD approach, specifically the MMPIC and DEM models, including the preliminary validation with catalyst dimension based on the Geldart group '''A''' and '''A '''' Miyauchi.<br />
<br />
==Introduction==<br />
<br />
Indonesia sepanjang 2019 mencapai 51,8 juta ton CPO, dari sumber tersebut dapat di olah menjadi green fuel, sebelum menjadi Green Fuel, CPO di olah dahulu menjadi Bleached and Deodorized Palm Oil (RBDPO) 100% kemudian di proses dengan metode Fluid Catalytic Cracking (FCC). The process of the FCC unit consists of the feed injection system, riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. Product pengolahan RBDPO dengan menggunakkan FCC yang utama adalah Gasoline, LCO (light cycle oil) dan LPG.<br />
<br />
Proses FCC adalah reaksi hydrocarbon antara crude oil (RBDPO) dengan catalyst, berdasarkan The Geldart Classification of Particles katalist pada FCC di golongkan pada group A dan Region A', Miyauchi menggolongkan katalis berdasarkan group A’ dengan properties diameter 50-70 Micron. The proper selection of catalyst is very important to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earths content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator dan riser adalah peralatan yang menentukan hasil product dari FCC sehingga pada paper ini menjelaskan transport katalis dari regenerator ke riser.<br />
<br />
Untuk mempelajari fenomena katalis pada FCC menggunakan hydrodynamics melalui pendekatan Computational Fluid Dynamics (CFD), pada pendekatan simulasi gas dan particle terdapat beberapa jenis metode yaitu, Eulerian, MPPIC, DEM. Setiap jenis metode memiliki karakteristik masing pada penyelesain masalah gas-particle, pada MPPIC adalah pendekatan dengan parcel in cell di mana solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). In the present formulation, different diameter particles of the same material must be defined as separate solid phases, each with its own statistical classification, pada paper ini mengnakan CFDSOFT sebagai device untuk menghitung fenomena katalist pada FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) numerical method for predicting dense gas-solids flow. The MP-PIC method is a hybrid method such as IBM method, where the gas-phase is treated as a continuum in the Eulerian reference frame and the solids are modeled in the Lagrangian reference frame by tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows and the method employs a fixed Eulerian grid and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the interactions between the particles are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
[[File:1PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where X is particle position, ܷUm is particle velocity, ''p'' m is particle density, ܸ Vm is particle volume, and t is time. The subscript ݉m is indicative of nodding to solids phase ݉, which in this case would indicate a unique solids class of particles.<br />
<br />
[[File:2PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Here ∇ um is the divergence operator with respect to the velocity, ܷUm and A m is the discrete particle-phase acceleration. The particle distribution function integrated over velocity and mass will yield the likely number of particles per unit volume at the position, X, at time t, for small intervals of (Vm + dVm, ''p''m + dpm, Um + dUm). The solids volume fraction, ''E''s, can then by represented through the distribution function using a volume integral.<br />
<br />
[[File:3PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
The solids phase is coupled to the Eulerian governing equations through the interphase momentum transfer term. Allowing Igm to be the contribution due to interphase momentum transfer between the gas and the m th solid phase, Where Dm is drag coefficient and ∇ p is pressure gradient.<br />
<br />
[[File:4PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
'''1.1 Mathematical model MPPIC'''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
'''Conservation of Mass'''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the particle’s statistical weight, Wp, and considering its mass change, dm/dt, under the effects of a chemical reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where R pn is the rate of production/consumption of the n th chemical species, and Np is the number of chemical species. This is not unlike the conservation of mass equation defined in Musser and Carney (2020). Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
'''Conservation of Species Mass'''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Where X pn is the n th chemical species mass fraction, and R pn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
'''Conservation of Translational Momentum'''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in the i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃'''g''' i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section '''Interparticle Stress''' below.<br />
<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:9PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ''E'' cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation, and ''B'' is an empirical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
'''Conservation of Internal Energy'''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is presented in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where C p and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction and/or phase change (h pn is the n the species-specific enthalpy) The last term, S p is a general source term. Note that S p might represent particle-particle heat transfer (currently 0 in PIC; there is no conduction model), fluid-particle heat transfer (convection), or radiative heat transfer (currently 0 in PIC; radiation model is pending).<br />
<br />
Pada studi ini juga melalakukan pemodelan dengan menggunkan metode DEM, Pemodelan dengan Computational Fluid Dynamics (CFD) coupling dengan DEM (Discrete element method), In such an approach, the trajectories of and the forces acting on individual particles are tracked directly. It offers a sound theoretical base to generally model the interactions between particles as well as with the surrounding fluid and screen wall. This cannot be achieved by widely used continuum methods such as two-fluid models, which have not, to date, been applied to simulate particle screen. In recent years, the CFD-DEM approach has been widely accepted as an effective tool to study various particle-fluid systems, as reviewed by different investigators. Despite the broad applications, only a few efforts have been reported to use the CFD-DEM method to study particle retention. Recently, Shaffee et al. used a CFD-DEM model to study the effect of adhesion on particle filtration by a screen and demonstrated that an increase in particle adhesion reduces the porosity and pressure drop across the sand pack covering the screen. These CFD-DEM studies have demonstrated the feasibility of this method in modeling sand screen, to some degree. However, to date, CFD-DEM studies on the influences of slot width-particle size ratios and wetting fluids on screen retention performance have not been reported in the literature. Besides, none of the previous CFD-DEM studies have attempted to analyze particle-fluid flow characteristics and force structures to understand the screen retention performance and identify the underlying mechanisms.<br />
<br />
'''1.2 Mathematical model CFD-DEM'''<br />
<br />
The current CFD-DEM model is based on the model used to simulate hydraulic conveying. For brevity, only the key features of the model are outlined below. However, detailed modeling and numerical treatments can be found elsewhere. <br />
<br />
'''Particle motion'''<br />
<br />
In the DEM model, the translational and rotational motion of a particle is governed by Newton's second law of motion, formulated as follows:<br />
<br />
[[File:DEM1.JPG|400px|thumb|centre|alt text]]<br />
<br />
where mi is the particle mass, Ii is the moment of inertia, vi is the particle translational velocity, ωi is the particle angular velocity, and ki is the number of particle/wall in contact with particle i. The translational motion of a particle is caused by the particle-fluid interaction forces including the drag force, fd, i. The pressure gradient force, f∇p, i and the viscous force, f∇. τ, i, the gravitational force, mig and the inter-particle contact forces such as the elastic force, fc, ij and the viscous damping force, fd, ij. The rotational motion is caused by the inter-particle contact forces due to particle/wall j which generate torques, Tij causing particle I to rotate. The particle motions are calculated based on a soft-sphere contact model proposed originally by Cundall and Strack, and the inter-particle contact forces are calculated according to the Hertzian contact theory. The equations used to calculate the interparticle contact forces and particle-fluid interaction forces involved in Eq. 1 are listed in Table 1.<br />
<br />
'''Fluid flow'''<br />
<br />
In the CFD model, the fluid flow is modeled in a similar way as those in the two-fluid model in the form of model A, in which the pressure is shared by both the liquid and solid phases [29,36]. The governing equations include the continuity equation and the Navier-Stokes equations:<br />
<br />
[[File:DEM2.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ρf is the fluid density, uf is the fluid velocity and p is the pressure, τ is the divergence of stress tensor that includes viscous and Reynolds<br />
<br />
Table 1<br />
The contact forces and particle-fluid interaction forces considered in the current model.<br />
<br />
[[File:DEM3.JPG|400px|thumb|centre|alt text]]<br />
<br />
Dengan menggunakan pendekatan MMPIC dan DEM mampu menjelaskan proses fenomena pada katalis. Pada skala besar FCC proses transfer katalis dari regenerator ke riser di atur oleh sliding valve atau dengan pluge valve dapat di lihat pada gambar di bawah. Akan tetapi pada skala pilot plant dengan diameter pipa transfer adalah 2 inch tidak di munggkinkan dengan menggunakan sliding valve karena sering terjadi stuck pada saat proses buka dan tutup untuk mengatur volume katalis menuju riser, selaintu sifat abrasi dari gas dan katalis memudahkan valve mudah rusak. Untuk itu dalam studi ini menjelaskan aplikasi seal loop untuk mengatur katalis pada FCC skala pilot plant. <br />
<br />
[[File:FCC_Pic.gif|1000px|thumb|centre|alt text]]<br />
<br />
The subject plan on this paper is a Replacement valve<br />
<br />
Pada gambar di bawah ini menjelaskan geometry pada loop-seal untuk mengatur laju aliran massa katalis ke riser. Dengan boundary kondisi batas katalis jatuh dari regenerator kemudian memenuhi loop-seal sampai ketinggian yang di tentukan kemudian air mendorong masuk dari sisi bawah untuk mengatur katalis keluar menuju riser. Pada gambar di bawah ini juga menjelaskan bahwa geometri pada saat pembentukan mesh pada CFDSOFT di bagi menjadi 5 body dimana untuk mempermudah saat pembentukan mesh yang baik.<br />
<br />
[[File:intro1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
<br />
Hasil simulasi dengan PIC-CFDSOFT dengan 1000 parcell di dapat sebagai berikut<br />
<br />
[[File:PIC1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
[[File:PIC2.JPG|1000px|thumb|centre|alt text]]<br />
<br />
Hasil simulasi dengan DEM-MFIX dengan 1000 parcell di dapat sebagai berikut:<br />
<br />
[[File:DEM-1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
[[File:DEM-2.JPG|1000px|thumb|centre|alt text]]<br />
<br />
==Simulation conditions==</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Draft1&diff=50325Draft12020-12-22T07:34:00Z<p>Agus.nuryadi: /* Introduction */</p>
<hr />
<div>'''penngunaan loop-seal pada proses transfer kalalis dari regenerator ke riser pada FCC skala pilotplant dengan menggunakan simulasi gas-particle<br />
'''<br />
==abstract==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows to use of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is chiffon or layered U pipe by flowing the air below to regulate the catalyst and solve the Riser's nitrogen leakage. This study uses the CFD approach, specifically the MMPIC and DEM models, including the preliminary validation with catalyst dimension based on the Geldart group '''A''' and '''A '''' Miyauchi.<br />
<br />
==Introduction==<br />
<br />
Indonesia sepanjang 2019 mencapai 51,8 juta ton CPO, dari sumber tersebut dapat di olah menjadi green fuel, sebelum menjadi Green Fuel, CPO di olah dahulu menjadi Bleached and Deodorized Palm Oil (RBDPO) 100% kemudian di proses dengan metode Fluid Catalytic Cracking (FCC). The process of the FCC unit consists of the feed injection system, riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. Product pengolahan RBDPO dengan menggunakkan FCC yang utama adalah Gasoline, LCO (light cycle oil) dan LPG.<br />
<br />
Proses FCC adalah reaksi hydrocarbon antara crude oil (RBDPO) dengan catalyst, berdasarkan The Geldart Classification of Particles katalist pada FCC di golongkan pada group A dan Region A', Miyauchi menggolongkan katalis berdasarkan group A’ dengan properties diameter 50-70 Micron. The proper selection of catalyst is very important to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earths content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator dan riser adalah peralatan yang menentukan hasil product dari FCC sehingga pada paper ini menjelaskan transport katalis dari regenerator ke riser.<br />
<br />
Untuk mempelajari fenomena katalis pada FCC menggunakan hydrodynamics melalui pendekatan Computational Fluid Dynamics (CFD), pada pendekatan simulasi gas dan particle terdapat beberapa jenis metode yaitu, Eulerian, MPPIC, DEM. Setiap jenis metode memiliki karakteristik masing pada penyelesain masalah gas-particle, pada MPPIC adalah pendekatan dengan parcel in cell di mana solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). In the present formulation, different diameter particles of the same material must be defined as separate solid phases, each with its own statistical classification, pada paper ini mengnakan CFDSOFT sebagai device untuk menghitung fenomena katalist pada FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) numerical method for predicting dense gas-solids flow. The MP-PIC method is a hybrid method such as IBM method, where the gas-phase is treated as a continuum in the Eulerian reference frame and the solids are modeled in the Lagrangian reference frame by tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows and the method employs a fixed Eulerian grid and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the interactions between the particles are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
[[File:1PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where X is particle position, ܷUm is particle velocity, ''p'' m is particle density, ܸ Vm is particle volume, and t is time. The subscript ݉m is indicative of nodding to solids phase ݉, which in this case would indicate a unique solids class of particles.<br />
<br />
[[File:2PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Here ∇ um is the divergence operator with respect to the velocity, ܷUm and A m is the discrete particle-phase acceleration. The particle distribution function integrated over velocity and mass will yield the likely number of particles per unit volume at the position, X, at time t, for small intervals of (Vm + dVm, ''p''m + dpm, Um + dUm). The solids volume fraction, ''E''s, can then by represented through the distribution function using a volume integral.<br />
<br />
[[File:3PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
The solids phase is coupled to the Eulerian governing equations through the interphase momentum transfer term. Allowing Igm to be the contribution due to interphase momentum transfer between the gas and the m th solid phase, Where Dm is drag coefficient and ∇ p is pressure gradient.<br />
<br />
[[File:4PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
'''1.1 Mathematical model MPPIC'''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
'''Conservation of Mass'''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the particle’s statistical weight, Wp, and considering its mass change, dm/dt, under the effects of a chemical reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where R pn is the rate of production/consumption of the n th chemical species, and Np is the number of chemical species. This is not unlike the conservation of mass equation defined in Musser and Carney (2020). Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
'''Conservation of Species Mass'''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Where X pn is the n th chemical species mass fraction, and R pn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
'''Conservation of Translational Momentum'''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in the i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃'''g''' i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section '''Interparticle Stress''' below.<br />
<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:9PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ''E'' cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation, and ''B'' is an empirical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
'''Conservation of Internal Energy'''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is presented in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where C p and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction and/or phase change (h pn is the n the species-specific enthalpy) The last term, S p is a general source term. Note that S p might represent particle-particle heat transfer (currently 0 in PIC; there is no conduction model), fluid-particle heat transfer (convection), or radiative heat transfer (currently 0 in PIC; radiation model is pending).<br />
<br />
Pada studi ini juga melalakukan pemodelan dengan menggunkan metode DEM, Pemodelan dengan Computational Fluid Dynamics (CFD) coupling dengan DEM (Discrete element method), In such an approach, the trajectories of and the forces acting on individual particles are tracked directly. It offers a sound theoretical base to generally model the interactions between particles as well as with the surrounding fluid and screen wall. This cannot be achieved by widely used continuum methods such as two-fluid models, which have not, to date, been applied to simulate particle screen. In recent years, the CFD-DEM approach has been widely accepted as an effective tool to study various particle-fluid systems, as reviewed by different investigators. Despite the broad applications, only a few efforts have been reported to use the CFD-DEM method to study particle retention. Recently, Shaffee et al. used a CFD-DEM model to study the effect of adhesion on particle filtration by a screen and demonstrated that an increase in particle adhesion reduces the porosity and pressure drop across the sand pack covering the screen. These CFD-DEM studies have demonstrated the feasibility of this method in modeling sand screen, to some degree. However, to date, CFD-DEM studies on the influences of slot width-particle size ratios and wetting fluids on screen retention performance have not been reported in the literature. Besides, none of the previous CFD-DEM studies have attempted to analyze particle-fluid flow characteristics and force structures to understand the screen retention performance and identify the underlying mechanisms.<br />
<br />
'''1.2 Mathematical model CFD-DEM'''<br />
<br />
The current CFD-DEM model is based on the model used to simulate hydraulic conveying. For brevity, only the key features of the model are outlined below. However, detailed modeling and numerical treatments can be found elsewhere. <br />
<br />
'''Particle motion'''<br />
<br />
In the DEM model, the translational and rotational motion of a particle is governed by Newton's second law of motion, formulated as follows:<br />
<br />
[[File:DEM1.JPG|400px|thumb|centre|alt text]]<br />
<br />
where mi is the particle mass, Ii is the moment of inertia, vi is the particle translational velocity, ωi is the particle angular velocity, and ki is the number of particle/wall in contact with particle i. The translational motion of a particle is caused by the particle-fluid interaction forces including the drag force, fd, i. The pressure gradient force, f∇p, i and the viscous force, f∇. τ, i, the gravitational force, mig and the inter-particle contact forces such as the elastic force, fc, ij and the viscous damping force, fd, ij. The rotational motion is caused by the inter-particle contact forces due to particle/wall j which generate torques, Tij causing particle I to rotate. The particle motions are calculated based on a soft-sphere contact model proposed originally by Cundall and Strack, and the inter-particle contact forces are calculated according to the Hertzian contact theory. The equations used to calculate the interparticle contact forces and particle-fluid interaction forces involved in Eq. 1 are listed in Table 1.<br />
<br />
'''Fluid flow'''<br />
<br />
In the CFD model, the fluid flow is modeled in a similar way as those in the two-fluid model in the form of model A, in which the pressure is shared by both the liquid and solid phases [29,36]. The governing equations include the continuity equation and the Navier-Stokes equations:<br />
<br />
[[File:DEM2.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ρf is the fluid density, uf is the fluid velocity and p is the pressure, τ is the divergence of stress tensor that includes viscous and Reynolds<br />
<br />
Table 1<br />
The contact forces and particle-fluid interaction forces considered in the current model.<br />
<br />
[[File:DEM3.JPG|400px|thumb|centre|alt text]]<br />
<br />
Dengan menggunakan pendekatan MMPIC dan DEM mampu menjelaskan proses fenomena pada katalis. Pada skala besar FCC proses transfer katalis dari regenerator ke riser di atur oleh sliding valve atau dengan pluge valve dapat di lihat pada gambar di bawah. Akan tetapi pada skala pilot plant dengan diameter pipa transfer adalah 2 inch tidak di munggkinkan dengan menggunakan sliding valve karena sering terjadi stuck pada saat proses buka dan tutup untuk mengatur volume katalis menuju riser, selaintu sifat abrasi dari gas dan katalis memudahkan valve mudah rusak. Untuk itu dalam studi ini menjelaskan aplikasi seal loop untuk mengatur katalis pada FCC skala pilot plant. <br />
<br />
[[File:FCC_Pic.gif|1000px|thumb|centre|alt text]]<br />
<br />
The subject plan on this paper is a Replacement valve<br />
<br />
Pada gambar di bawah ini menjelaskan geometry pada loop-seal untuk mengatur laju aliran massa katalis ke riser. Dengan boundary kondisi batas katalis jatuh dari regenerator kemudian memenuhi loop-seal sampai ketinggian yang di tentukan kemudian air mendorong masuk dari sisi bawah untuk mengatur katalis keluar menuju riser. Pada gambar di bawah ini juga menjelaskan bahwa geometri pada saat pembentukan mesh pada CFDSOFT di bagi menjadi 5 body dimana untuk mempermudah saat pembentukan mesh yang baik.<br />
<br />
[[File:intro1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
<br />
Hasil simulasi dengan PIC-CFDSOFT dengan 1000 parcell di dapat sebagai berikut<br />
<br />
[[File:PIC1.JPG.JPG|1000px|thumb|centre|alt text]]<br />
<br />
[[File:PIC2.JPG|1000px|thumb|centre|alt text]]<br />
<br />
Hasil simulasi dengan DEM-MFIX dengan 1000 parcell di dapat sebagai berikut:<br />
<br />
[[File:DEM-1.JPG.JPG|1000px|thumb|centre|alt text]]<br />
<br />
[[File:DEM-2.JPG|1000px|thumb|centre|alt text]]<br />
<br />
==Simulation conditions==</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:DEM-2.JPG&diff=50324File:DEM-2.JPG2020-12-22T07:33:43Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:DEM-1.JPG&diff=50323File:DEM-1.JPG2020-12-22T07:33:28Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:PIC2.JPG&diff=50322File:PIC2.JPG2020-12-22T07:31:07Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:PIC1.JPG&diff=50321File:PIC1.JPG2020-12-22T07:30:35Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=Draft1&diff=50292Draft12020-12-22T06:36:19Z<p>Agus.nuryadi: /* Introduction */</p>
<hr />
<div>'''penngunaan loop-seal pada proses transfer kalalis dari regenerator ke riser pada FCC skala pilotplant dengan menggunakan simulasi gas-particle<br />
'''<br />
==abstract==<br />
<br />
Computational fluid dynamics (CFD) is robust in predicting and analyzing complex multiphase flow hydrodynamics, especially on fluid catalytic cracking (FCC) phenomena in fluid-solid reaction. This study presented the replacement valve as a regulator of the catalyst's distribution from the Regenerator to the Riser in a pilot-scale fluid catalytic cracking (FCC). On a large scale, FCC applies Slide valves/plug valves as a regulator of the catalyst rate from the Regenerator to the Riser also stops nitrogen flow Riser. However, Slide valves are carefully designed with abrasion-resistant protection for improving the reliability of the valve. Internal insulation allows to use of carbon steel for the body of the valves. It is impossible on a pilot plant scale because the dimeter pipe is small, making the catalyst often stuck in the valve and nitrogen escapes to the Riser. The solution is chiffon or layered U pipe by flowing the air below to regulate the catalyst and solve the Riser's nitrogen leakage. This study uses the CFD approach, specifically the MMPIC and DEM models, including the preliminary validation with catalyst dimension based on the Geldart group '''A''' and '''A '''' Miyauchi.<br />
<br />
==Introduction==<br />
<br />
Indonesia sepanjang 2019 mencapai 51,8 juta ton CPO, dari sumber tersebut dapat di olah menjadi green fuel, sebelum menjadi Green Fuel, CPO di olah dahulu menjadi Bleached and Deodorized Palm Oil (RBDPO) 100% kemudian di proses dengan metode Fluid Catalytic Cracking (FCC). The process of the FCC unit consists of the feed injection system, riser, riser outlet separator system, disengager/stripper, regenerator, catalyst cooler (optional), catalyst withdrawal well, catalyst transfer lines, and control systems. Product pengolahan RBDPO dengan menggunakkan FCC yang utama adalah Gasoline, LCO (light cycle oil) dan LPG.<br />
<br />
Proses FCC adalah reaksi hydrocarbon antara crude oil (RBDPO) dengan catalyst, berdasarkan The Geldart Classification of Particles katalist pada FCC di golongkan pada group A dan Region A', Miyauchi menggolongkan katalis berdasarkan group A’ dengan properties diameter 50-70 Micron. The proper selection of catalyst is very important to successful residue cracking operations. The importance of magnifies as the percentage of residual oil increases in the feedstock. Several properties of the catalyst should be examined for a particular feed. The properties are, Zeolite content, Micro-activity, Rare earths content, Unit cell size, Coke selectivity, Particle size distribution, Bulk density, Thermal stability, Surface area, Pore volume and pore distribution (strippability), Attrition resistance, Metals resistance, Gasoline octane properties. Regenerator dan riser adalah peralatan yang menentukan hasil product dari FCC sehingga pada paper ini menjelaskan transport katalis dari regenerator ke riser.<br />
<br />
Untuk mempelajari fenomena katalis pada FCC menggunakan hydrodynamics melalui pendekatan Computational Fluid Dynamics (CFD), pada pendekatan simulasi gas dan particle terdapat beberapa jenis metode yaitu, Eulerian, MPPIC, DEM. Setiap jenis metode memiliki karakteristik masing pada penyelesain masalah gas-particle, pada MPPIC adalah pendekatan dengan parcel in cell di mana solids model tracks the position and trajectory of computational parcels, statistical groups of particles that share the same physical characteristics (e.g. diameter and density). In the present formulation, different diameter particles of the same material must be defined as separate solid phases, each with its own statistical classification, pada paper ini mengnakan CFDSOFT sebagai device untuk menghitung fenomena katalist pada FCC.<br />
<br />
The multiphase particle-in-cell (MP-PIC) numerical method for predicting dense gas-solids flow. The MP-PIC method is a hybrid method such as IBM method, where the gas-phase is treated as a continuum in the Eulerian reference frame and the solids are modeled in the Lagrangian reference frame by tracking computational particles. The MPPIC is a derivative of the Particle-in-Cell (PIC) method for multiphase flows and the method employs a fixed Eulerian grid and Lagrangian parcels are used to transport mass, momentum, and energy through this grid in a way that preserves the identities of the different materials associated with the particles. The main distinction with traditional Eulerian-Lagrangian methods is that the interactions between the particles are calculated on the Eulerian grid. The Eulerian-Lagrangian method and the multiphase particle in cell (MPPIC) method have been used in this study. The model of the MPPIC is a Model Collision in CFDSOF, first of all, PIC models are derived from a Liouville equation describing the time evolution of a particle distribution function.<br />
<br />
[[File:1PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where X is particle position, ܷUm is particle velocity, ''p'' m is particle density, ܸ Vm is particle volume, and t is time. The subscript ݉m is indicative of nodding to solids phase ݉, which in this case would indicate a unique solids class of particles.<br />
<br />
[[File:2PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Here ∇ um is the divergence operator with respect to the velocity, ܷUm and A m is the discrete particle-phase acceleration. The particle distribution function integrated over velocity and mass will yield the likely number of particles per unit volume at the position, X, at time t, for small intervals of (Vm + dVm, ''p''m + dpm, Um + dUm). The solids volume fraction, ''E''s, can then by represented through the distribution function using a volume integral.<br />
<br />
[[File:3PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
The solids phase is coupled to the Eulerian governing equations through the interphase momentum transfer term. Allowing Igm to be the contribution due to interphase momentum transfer between the gas and the m th solid phase, Where Dm is drag coefficient and ∇ p is pressure gradient.<br />
<br />
[[File:4PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
'''1.1 Mathematical model MPPIC'''<br />
<br />
The word particle, a single piece of material, spherical in nature, having physical characteristics that can be uniquely defined (like density, chemical composition, etc.); the word parcel indicates a statistical collection of particles of similar physical characteristics.<br />
<br />
'''Conservation of Mass'''<br />
<br />
The conservation of mass (or continuity equation) for the p th MPPIC parcel is given by managing the particle’s statistical weight, Wp, and considering its mass change, dm/dt, under the effects of a chemical reaction.<br />
<br />
[[File:5PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where R pn is the rate of production/consumption of the n th chemical species, and Np is the number of chemical species. This is not unlike the conservation of mass equation defined in Musser and Carney (2020). Specifically, the right-hand side of (eq above) accounts for interphase mass transfer because of heterogeneous chemical reactions or physical processes, like evaporation. In non-chemically reactive simulations (or those without phase change), the right side of Equation (eq above) equals zero.<br />
<br />
'''Conservation of Species Mass'''<br />
<br />
The n th species mass conservation equation for the MMPIC parcel is given by:<br />
<br />
[[File:6PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
Where X pn is the n th chemical species mass fraction, and R pn is the rate of formation of species mass attributed to chemical reactions or physical processes. In non-chemically reactive simulations (or those without phase change), the right side of Equation (above) equals zero.<br />
<br />
'''Conservation of Translational Momentum'''<br />
<br />
The general conservation of translation momentum for the p th MMPIC parcel in the i th coordinate direction is given by:<br />
<br />
[[File:7PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ܷU i is the parcel velocity, and ݃'''g''' i is the gravity body force. The first term on the right-hand side is the gravitational body force. The second term is a PIC-specific term derived from interparticle stress, described in detail in the section '''Interparticle Stress''' below.<br />
<br />
As expected, the position of a parcel is related to its velocity through:<br />
<br />
[[File:8PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where Xi is the parcel position in the ݅i th coordinate direction.<br />
<br />
'''Interparticle Stress'''<br />
<br />
The interparticle stress variable follows the form suggested by Snider (2001). Specifically,<br />
<br />
[[File:9PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ''E'' cp indicates a pre-determined, problem-specific, close-pack volume fraction for the solids phase. P s is an empirical pressure constant relatable to the scale and unit of the problem under evaluation, and ''B'' is an empirical unitless exponent, usually between 2 and 5. alpha is a tiny constant (e.g. 1e-7) to assure a non-zero denominator in calculations.<br />
<br />
'''Conservation of Internal Energy'''<br />
<br />
The general conservation of internal energy for the p th MMPIC parcel follows the same theoretical underpinnings as DEM. The internal energy is presented in terms of temperature. For an isothermal parcel (a PIC assumption),<br />
<br />
[[File:10PIC.JPG|400px|thumb|centre|alt text]]<br />
<br />
where C p and ܶT are parcel specific heat and temperature (same as particle values). The first term on the right-hand side represents changes in internal energy accompanying species formation or destruction from a chemical reaction and/or phase change (h pn is the n the species-specific enthalpy) The last term, S p is a general source term. Note that S p might represent particle-particle heat transfer (currently 0 in PIC; there is no conduction model), fluid-particle heat transfer (convection), or radiative heat transfer (currently 0 in PIC; radiation model is pending).<br />
<br />
Pada studi ini juga melalakukan pemodelan dengan menggunkan metode DEM, Pemodelan dengan Computational Fluid Dynamics (CFD) coupling dengan DEM (Discrete element method), In such an approach, the trajectories of and the forces acting on individual particles are tracked directly. It offers a sound theoretical base to generally model the interactions between particles as well as with the surrounding fluid and screen wall. This cannot be achieved by widely used continuum methods such as two-fluid models, which have not, to date, been applied to simulate particle screen. In recent years, the CFD-DEM approach has been widely accepted as an effective tool to study various particle-fluid systems, as reviewed by different investigators. Despite the broad applications, only a few efforts have been reported to use the CFD-DEM method to study particle retention. Recently, Shaffee et al. used a CFD-DEM model to study the effect of adhesion on particle filtration by a screen and demonstrated that an increase in particle adhesion reduces the porosity and pressure drop across the sand pack covering the screen. These CFD-DEM studies have demonstrated the feasibility of this method in modeling sand screen, to some degree. However, to date, CFD-DEM studies on the influences of slot width-particle size ratios and wetting fluids on screen retention performance have not been reported in the literature. Besides, none of the previous CFD-DEM studies have attempted to analyze particle-fluid flow characteristics and force structures to understand the screen retention performance and identify the underlying mechanisms.<br />
<br />
'''1.2 Mathematical model CFD-DEM'''<br />
<br />
The current CFD-DEM model is based on the model used to simulate hydraulic conveying. For brevity, only the key features of the model are outlined below. However, detailed modeling and numerical treatments can be found elsewhere. <br />
<br />
'''Particle motion'''<br />
<br />
In the DEM model, the translational and rotational motion of a particle is governed by Newton's second law of motion, formulated as follows:<br />
<br />
[[File:DEM1.JPG|400px|thumb|centre|alt text]]<br />
<br />
where mi is the particle mass, Ii is the moment of inertia, vi is the particle translational velocity, ωi is the particle angular velocity, and ki is the number of particle/wall in contact with particle i. The translational motion of a particle is caused by the particle-fluid interaction forces including the drag force, fd, i. The pressure gradient force, f∇p, i and the viscous force, f∇. τ, i, the gravitational force, mig and the inter-particle contact forces such as the elastic force, fc, ij and the viscous damping force, fd, ij. The rotational motion is caused by the inter-particle contact forces due to particle/wall j which generate torques, Tij causing particle I to rotate. The particle motions are calculated based on a soft-sphere contact model proposed originally by Cundall and Strack, and the inter-particle contact forces are calculated according to the Hertzian contact theory. The equations used to calculate the interparticle contact forces and particle-fluid interaction forces involved in Eq. 1 are listed in Table 1.<br />
<br />
'''Fluid flow'''<br />
<br />
In the CFD model, the fluid flow is modeled in a similar way as those in the two-fluid model in the form of model A, in which the pressure is shared by both the liquid and solid phases [29,36]. The governing equations include the continuity equation and the Navier-Stokes equations:<br />
<br />
[[File:DEM2.JPG|400px|thumb|centre|alt text]]<br />
<br />
where ρf is the fluid density, uf is the fluid velocity and p is the pressure, τ is the divergence of stress tensor that includes viscous and Reynolds<br />
<br />
Table 1<br />
The contact forces and particle-fluid interaction forces considered in the current model.<br />
<br />
[[File:DEM3.JPG|400px|thumb|centre|alt text]]<br />
<br />
Dengan menggunakan pendekatan MMPIC dan DEM mampu menjelaskan proses fenomena pada katalis. Pada skala besar FCC proses transfer katalis dari regenerator ke riser di atur oleh sliding valve atau dengan pluge valve dapat di lihat pada gambar di bawah. Akan tetapi pada skala pilot plant dengan diameter pipa transfer adalah 2 inch tidak di munggkinkan dengan menggunakan sliding valve karena sering terjadi stuck pada saat proses buka dan tutup untuk mengatur volume katalis menuju riser, selaintu sifat abrasi dari gas dan katalis memudahkan valve mudah rusak. Untuk itu dalam studi ini menjelaskan aplikasi seal loop untuk mengatur katalis pada FCC skala pilot plant. <br />
<br />
[[File:FCC_Pic.gif|1000px|thumb|centre|alt text]]<br />
<br />
The subject plan on this paper is a Replacement valve<br />
<br />
Pada gambar di bawah ini menjelaskan geometry pada loop-seal untuk mengatur laju aliran massa katalis ke riser. Dengan boundary kondisi batas katalis jatuh dari regenerator kemudian memenuhi loop-seal sampai ketinggian yang di tentukan kemudian air mendorong masuk dari sisi bawah untuk mengatur katalis keluar menuju riser. Pada gambar di bawah ini juga menjelaskan bahwa geometri pada saat pembentukan mesh pada CFDSOFT di bagi menjadi 5 body dimana untuk mempermudah saat pembentukan mesh yang baik.<br />
<br />
[[File:intro1.JPG|1000px|thumb|centre|alt text]]<br />
<br />
==Simulation conditions==</div>Agus.nuryadihttp://air.eng.ui.ac.id/index.php?title=File:Intro1.JPG&diff=50291File:Intro1.JPG2020-12-22T06:36:05Z<p>Agus.nuryadi: </p>
<hr />
<div></div>Agus.nuryadi