FCC Riser Unit Operated in the Heat-Transfer Mode:  Kinetic Modeling

Blasetti, A.; Lasa, Hugo de

doi:10.1021/ie950704v

Cited by 16 publications

(11 citation statements)

References 4 publications

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“…The main advantage of this model is its ability to predict coke production. This four lump model was used for the development of correlations and carry out different parametric studies on various aspects of FCC modeling [5][6][7][8][9]. Five lump kinetic models developed by Ancheyta et al [10] and Bollas et al [11] included 7 and 9 rate constants respectively.…”

Section: Introductionmentioning

confidence: 99%

Parametric Sensitivity Studies in a Commercial FCC Unit

Dasila¹,

Choudhury²,

Saraf³

et al. 2012

ACES

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A steady state model was developed for simulating the performance of an industrial fluid catalytic cracking (FCC) unit which was subsequently used in parametric sensitivity studies. The simulator includes kinetic models for the riser reactor and the regeneration systems. Mass and energy balances were performed for each of these sections and simulation results were compared with the plant data available in the literature. Model predictions were found to be in close agreement with the reported data. Finally this validated model was used for studying the effects of independent variables such as feed preheat temperature (T feed ) and feed flow rate (F feed ) on the unit performance at either fixed regenerated catalyst temp/regenerator temp (T rgn ) or constant reactor outlet temperature (ROT). The catalyst circulation rate (CCR) was automatically adjusted to keep the ROT constant with varying the independent variables feed preheat temperature while the air rate adjusted for keeping the regenerator temperature constant which consequences the dependency of both dependent and independent variables on the unit performance. The air flow rate to the regenerator was also an independent variable during the parametric sensitivity analysis and its effect on FCC performance was investigated at constant T feed , F feed and CCR. Combining all the sensitivity analysis, it has been found to increase gas oil conversion and product yields by 5 to 6 percent with decrease of say, 10 K, in the feed preheat temperature (T feed ) and corresponding increase in air rate (F air ) and catalyst circulation rate (F rgc ) at constant reactor outlet temperature (ROT) and regenerated catalyst temperature (T rgc ).

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Section: Introductionmentioning

confidence: 99%

Parametric Sensitivity Studies in a Commercial FCC Unit

Dasila¹,

Choudhury²,

Saraf³

et al. 2012

ACES

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“…Three or more lumps are usually considered (Weekman and Nace, 1970, Nace et al, 1971, Jacob et al, 1976, Derouin et al 1997, Ali and Rohani, 1997, Blasetti and De Lasa,, 1997, Arandes et al 2000. Therefore, it is common practice to use a "lumping" technique to model the reaction kinetics.…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of a Reacting Gas/Solid Flow in the Riser Section of an Industrial Fluid Catalytic Cracking Unit

Benyahia¹,

Ortiz

Paredes

2003

International Journal of Chemical Reactor Engineering

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The Fluid Catalytic Cracking (FCC) is an important process in a refinery used mainly to produce higher value gasoline from heavy hydrocarbons. An FCC unit can crack different type of feeds and can use different types of catalysts during its lifetime, which makes this process very flexible and profitable. In this paper, an industrial unit located in Mexico was analyzed and the computational results were compared with available design data. The FCC process involves complex reaction kinetics along with multiphase flow hydrodynamics and heat transfer. This makes it nearly impossible to model every physical phenomenon that occurs in this process. However, an interesting model should be able to predict reasonably well the yields of the cracking reactions. Cracking reactions are catalytic, and the catalyst distribution in the riser needs to be known a priori. Therefore, we modeled the physical process as a gas/solid multiphase flow with reaction. A transient Eulerian approach plus a simple 3-lumps reaction kinetic scheme (Nace et al., 1971) describe the multiphase flow model. The gas density was assumed to follow an ideal gas law, and can, thus, change with the number of moles in the system. Conservation of mass, momentum, and species (heavy oil, gasoline and gas+coke) were solved. The gas/solid hydrodynamics and the yields of the reacting species were predicted in the 2-D Riser section of the FCC unit. The results showed a dramatic effect of the change in the number of moles of the chemical species on the hydrodynamics. The increase in the number of moles due to the cracking reactions resulted in a significant increase in the gas flow rate, which changed significantly the flow regime. The reaction yields compared reasonably well with the design data for this specific unit.

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“…The inclusion of the above discussed constants into the mathematical model implied the modification of Equations (9) and (11). Then, the two equations were rewritten, respectively, as follows:…”

Section: Inverse Methodology Of Parameter Estimationmentioning

confidence: 99%

“…It was also shown that the catalyst deactivation function is dependent on the feedstock type. On the other hand, simple kinetic models, with a small number of lumps, 5,11,12 require fewer kinetic constants to be determined and are simple to solve numerically.…”

Section: Introductionmentioning

confidence: 99%

The inverse methodology of parameter estimation for model adjustment, design, simulation, control and optimization of fluid catalytic cracking (FCC) risers

Souza

Vargas

Meien

et al. 2008

J of Chemical Tech & Biotech

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BACKGROUND: A simple model is required to produce a fast computational code that is sufficiently precise to be used for the design, simulation, control and optimization of fluid catalytic cracking (FCC) risers. This work experimentally validates and adjusts a simplified FCC riser model using available experimental data, and proposes utilization of the inverse problem of the parameter estimation method to fit any existing kinetic model to a specific feedstock/catalyst set for general application.

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FCC Riser Unit Operated in the Heat-Transfer Mode: Kinetic Modeling

Cited by 16 publications

References 4 publications

Parametric Sensitivity Studies in a Commercial FCC Unit

Parametric Sensitivity Studies in a Commercial FCC Unit

Numerical Analysis of a Reacting Gas/Solid Flow in the Riser Section of an Industrial Fluid Catalytic Cracking Unit

The inverse methodology of parameter estimation for model adjustment, design, simulation, control and optimization of fluid catalytic cracking (FCC) risers

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