Dynamic modeling and simulation of a catalytic cracking unit

Zheng, Yong

doi:10.1016/0098-1354(94)85021-6

Cited by 25 publications

(15 citation statements)

References 3 publications

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“…In this model, the open-loop transient behavior was used to find the optimum operating conditions that give maximum gasoline yield in the open-loop mode. Zheng [18] presented another dynamic model for the riser-type FCCU. This model simulates the startup, shutdown and routine operation of the unit.…”

Section: Mcfarlane Et Almentioning

confidence: 99%

Dynamic modeling and simulation of a riser‐type fluid catalytic cracking unit

Ali

Rohani

1997

Chem Eng & Technol

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A dynamic model is developed for a fluid catalytic cracking (FCC) unit to describe the dynamic behavior of both the riser and the regenerator reactors and their interactions. The cracking reactions are simulated by the four-lumped kinetic model [l]. The reactions in the riser occur in a transported bed with the fluid and the solids in ideal plug flow. The twophase nature of the regenerator-fluidized bed is considered and the kinetic model for the coke combustion on the cracking catalyst [2,3] is incorporated. The proposed model is validated using steady-state plant data from an industrial unit and the results are found to be in good agreement. One of the main advantages of the model is that it does not include any partial differential equations. This facilitates the solution of the equations and makes the model particularly suitable for control studies. Simulation studies are performed to investigate the effect of changing various process variables, such as catalyst circulation rate, gas oil feed rate, and oxygen feed concentration.

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Section: Mcfarlane Et Almentioning

confidence: 99%

Dynamic modeling and simulation of a riser‐type fluid catalytic cracking unit

Ali

Rohani

1997

Chem Eng & Technol

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“…The modified model is validated using steady-state plant data from an industrial unit (Consumer's Co-operative Refineries Ltd., Regina, SK) and the results are found to be in good agreement.Le modele dynamique mis au point par Ali et Rohani (1997) Elnashaie and Elshishini, 1993; McFarlene et al, 1993;Zheng, 1994;Arbel et al, 1995; Ali and Rohani, 1997). We would limit the discussion to only three important models presented previously.…”

mentioning

confidence: 97%

“…Numerous articles relating to the FCC process can be found in literature. Nevertheless, very few dynamic models have been presented in the literature (Lee and Groves, 1985; Lopez-Isunza and Ruiz-Martinez, 199 1 ; Elnashaie and Elshishini, 1993;McFarlene et al, 1993;Zheng, 1994;Arbel et al, 1995;Ali and Rohani, 1997). We would limit the discussion to only three important models presented previously.…”

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confidence: 99%

The modified dynamic model of a riser type fluid catalytic cracking unit

1999

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The dynamic model developed by Ali and Rohani (1997) to describe the transient behavior of a fluid catalytic cracking (FCC) unit is modified (i) to incorporate the effect of volumetric expansion of the feed and product gases flowing in the riser reactor (ii) to consider the enhancement of mass and heat transfer coefficients due to high turbulence in the rcgenerator and (iii) to model the reactor and stripper as a continuous stirred tank. The modified model is validated using steady-state plant data from an industrial unit (Consumer's Co-operative Refineries Ltd., Regina, SK) and the results are found to be in good agreement.Le modele dynamique mis au point par Ali et Rohani (1997) Elnashaie and Elshishini, 1993; McFarlene et al., 1993;Zheng, 1994;Arbel et al., 1995; Ali and Rohani, 1997). We would limit the discussion to only three important models presented previously. McFarlene et al. (1993) published a dynamic model to describe a Model IV FCC Unit. Their model consists of a combination of empirical and semi-empirical correlations with limited predictive capability. Moreover, the modem refineries use the riser type FCC units and Model IV units are considered to be obsolete. The McFarlene et al. (1993) model is particularly valuable as it presents a detailed and realistic description of the fluid dynamic behavior of the regenerator, but the model lacks a vivid description of the cracking reactions.Arbel et ai. (1995) presented a dynamic model of the FCC unit and studied the stability and existence of multiple steady-states in the FCC operation. In this model, the riser is described as an ideal plug flow reactor under quasi-steadystate and adiabatic conditions with no slip velocity between the solids and the gases. They have used the ten-lumped kinetic model of Jacob et al. (1976) to describe the cracking kinetics. The stripper has been modeled as a well mixed stirred tank with a linear stripping function and a constant temperature drop. The regenerator model consists of dense and dilute phases. The dense bed is firther divided into emulsion phase, which is modeled as a CSTR, and bubble phase, which is modeled as three CSTRs in series. This *Author to whom all correspondence should be addressed. E-mail address: rohani@engr.usask.ca model also incorporates the effect of entrainment of the catalyst in the dilute phase. The combustion reactions take place in the dilute phase or freeboard region. The dilute phase is also modeled as a series of three CSTRs.Ali and Rohani (1997) presented a simple dynamic model without using any partial differential equations to describe the modem FCC units. The model is divided into two parts, the rise reactor and the regenerator. The riser is modeled as an ideal plug flow reactor under quasi-steady-state and adiabatic conditions with a constant superficial gas velocity and zero slip velocity between the gas and solid phase. They used a four-lumped kinetic scheme (Lee et at., 1989) to describe the cracking reactions. The regenerator is modcled as a combination of a dense ...

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“…The FCC plant also proves to be very suitable for the testing of model-based algorithms and for investigating the capabilities of models developed for process control experiments. This role of FCC plant is strongly emphasized in the literature (Grosididier [1], Hovd [2], Lee [3], McFarlane [4,5], Tatrai [7±9], Zheng [13]). …”

Section: Introductionmentioning

confidence: 98%

Coordinated Control of a Fluid Catalytic Cracking Unit

Kiss

Szeifert

1998

Chem. Eng. Technol.

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A new approach to coordinated control in the chemical industries is presented in this paper. A Multivariable Model Predictive Controller (MVPC) is applied at the coordinating control level. The design and application of the MVPC is introduced and demonstrated. A well structured, first principle dynamic model was developed for the regenerator/reactor section of a FCC plant. The control experiments are carried out on a dynamic simulator based on the dynamic model and written in Matlab/Simulink programming language.

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Dynamic modeling and simulation of a catalytic cracking unit

Cited by 25 publications

References 3 publications

Dynamic modeling and simulation of a riser‐type fluid catalytic cracking unit

Dynamic modeling and simulation of a riser‐type fluid catalytic cracking unit

The modified dynamic model of a riser type fluid catalytic cracking unit

Coordinated Control of a Fluid Catalytic Cracking Unit

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