Numerical Simulation of an Industrial Fluid Catalytic Cracking Regenerator

2013 ◽  
Author(s):  
Guangwu Tang ◽  
Armin Silaen ◽  
Bin Wu ◽  
Chenn Q. Zhou ◽  
Dwight Agnello-Dean ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Catalytic Cracking ◽  
Catalyst Surface ◽  
Solid Phase ◽  
Catalyst Activity ◽  
Cylindrical Vessel ◽  
Fluid Catalytic Cracking ◽  
Solid Catalyst ◽  
Momentum Exchange ◽  
Two Phases

Fluid catalytic cracking (FCC) is one of the most important conversion processes in petroleum refineries, and FCC regenerator is a key part of an FCC unit to recover the solid catalyst activity by burning off the deposited coke on the catalyst surface. In modern FCC units, regenerator is a cylindrical vessel. Carrier gas transports the solid catalyst from the stripper and feeds the catalyst into the regenerator through catalyst distributors. The catalyst is fluidized by the air that is injected into the regenerator through air rings in the bottom part of the cylindrical vessel. A three-dimensional multi-phase, multi-species reacting flow computational fluid dynamics (CFD) model was established to simulate the flow inside an FCC regenerator. The two phases involved in the flow are gas phase and solid phase. The Euler-Euler approach, where the two phases are considered to be continuous and fully inter-penetrating, is employed. The model includes gas-solid momentum exchange, gas-solid heat exchange, gas-solid mass exchange, and chemical reactions. Chemical reactions incorporated into the model simulate the combustion of coke which is present on the catalyst surface. The simulation results show a good agreement with plant data.

Numerical Simulation of an Industrial Fluid Catalytic Cracking Regenerator

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Guangwu Tang ◽  
Armin K. Silaen ◽  
Bin Wu ◽  
Chenn Q. Zhou ◽  
Dwight Agnello-Dean ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Catalytic Cracking ◽  
Catalyst Surface ◽  
Three Dimensional ◽  
Fluid Catalytic Cracking ◽  
Solid Catalyst ◽  
Reacting Flow ◽  
Momentum Exchange ◽  
Petroleum Refineries ◽  
Two Phases

Fluid catalytic cracking (FCC) is one of the most important conversion processes in petroleum refineries, and the FCC regenerator is a key part of an FCC unit utilized in the recovery of solid catalyst reactivity by burning off the deposited coke on the catalyst surface. A three-dimensional multiphase, multispecies reacting flow computational fluid dynamics (CFD) model was established to simulate the flow and reactions inside an FCC regenerator. The Euler–Euler approach, where the two phases (gas and solid) are considered to be continuous and fully interpenetrating, is employed. The model includes gas–solid momentum exchange, gas–solid heat exchange, gas–solid mass exchange, and chemical reactions. Chemical reactions incorporated into the model simulate the combustion of coke which is present on the catalyst surface. The simulation results were validated by plant data.

Effect of irradiation and of replacement of hydrogen by deuterium on the kinetics of hydrogenation of maleic acid on a nickel catalyst

1980 ◽  
Vol 45 (6) ◽  
pp. 1632-1638 ◽  
Author(s):  
Rostislav Kudláček ◽  
Růžena Jelínková
Keyword(s):  
Reaction Rate ◽  
Catalyst Surface ◽  
Catalyst Activity ◽  
Hydrogenation Reaction ◽  
Gamma Dose ◽  
Model Reaction ◽  
Solid Catalyst ◽  
Liquid Phase Hydrogenation ◽  
Kinetics Of ◽  
Preliminary Irradiation

Liquid phase hydrogenation reaction was studied on modifying the solid catalyst by preliminary irradiation and replacing the reacting hydrogen by deuterium; the changes in the reaction rate were measured and the phenomena on the catalyst surface, particularly the change in the catalyst activity, were investigated. For the model reaction, the dependences of the reaction rate on the temperature of reduction and of the successive activation of the catalyst on the absorbed gamma dose were followed, and the dependences of the reaction rate on the reaction temperature were compared for the hydrogenation and deuteration. Isotope effect was found in the influence of the reacting medium on the catalyst property. The activity of the nickel carrier catalyst is governed by its interaction with hydrogen after the reduction, particularly by the temperature of this process.

Sulphur reduction in fluid catalytic cracking using a kaolin in situ crystallization catalyst modified with vanadium

Clay Minerals ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 281-288 ◽  
Author(s):  
Ya-Li Dai ◽  
Shu-Qin Zheng ◽  
Dong Qian
Keyword(s):  
Catalytic Cracking ◽  
Comprehensive Evaluation ◽  
Catalyst Activity ◽  
Reduction Rate ◽  
Liquid Product ◽  
Fluid Catalytic Cracking ◽  
Lewis Acidity ◽  
Sulphur Reduction ◽  
In Situ Crystallization

AbstractSulphur reduction catalysts represent a viable option for S reduction in the fluid catalytic cracking (FCC) process. In this paper, a kaolin in situ crystallization catalyst was modified with vanadium and evaluated in a fixed fluid bed (FFB) reactor. The relation between the acidity of the catalyst, the S reduction rate and the catalyst activity is discussed. The results show that increasing weak Lewis acid acidity favours S reduction in the FCC process. Increasing the V content enhances the weak Lewis acidity, so causing the S reduction rate to increase. The kaolin in situ crystallization catalyst modified with 0.6 wt.% of V leads to a 34.5% reduction in the S content of the liquid product. Comprehensive evaluation of the FFB results and the S reduction ability indicates that the catalyst modified with 0.45 wt.% V provided the best performance.

Simulation of the Rheology of Semisolid Alloys by Using a Two-phase Flow Approach

2000 ◽  
Vol 652 ◽  
Author(s):  
A. Ludwig ◽  
M. Wu ◽  
T. Hofmeister
Keyword(s):  
Two Phase Flow ◽  
Solid Phase ◽  
Numerical Models ◽  
Flow Behavior ◽  
Phase Flow ◽  
Momentum Exchange ◽  
Two Phase ◽  
Semisolid Alloys ◽  
Dependent Flow ◽  
Two Phases

ABSTRACTSemisolid alloys exhibit a shear rate history dependent flow behavior. The increasing interest on numerical modeling of thixo-casting processes makes it quite important to understand the flow behavior of semisolids. Its apparent viscosity is the key parameter for the numerical models. In this paper a two phase approach is used to investigate the rheology of semisolid alloys. It is assumed that both, liquid and solid phase, can be regarded as inter-penetrating continua with its own viscosity. Thus, each phase is thought to behave as a Newtonian fluid. The simulation results show that the rheology of the two-phase flow is determined by the interaction between the solid and the liquid, i.e. the momentum exchange between the two phases. Non-Newtonian flow behavior of the solid-liquid mixture is predicted although both phases are considered as Newtonian fluids.

Modelling Catalyst Deactivation by External Coke Deposition during Fluid Catalytic Cracking

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Gladys Jiménez-García ◽  
Roberto Quintana-Solórzano ◽  
Ricardo Aguilar-López ◽  
Rafael Maya-Yescas
Keyword(s):  
Catalytic Cracking ◽  
Catalyst Deactivation ◽  
Catalyst Activity ◽  
Effective Diffusivity ◽  
Fluid Catalytic Cracking ◽  
Coke Deposition ◽  
Negative Exponential Function ◽  
Operating Variables ◽  
Laboratory Reactor ◽  
Negative Exponential

Although the Fluid Catalytic Cracking (FCC) is an economic important process, simulation of its kinetics is rather empirical—mainly it is a consequence of the complex interactions among operating variables and the complex kinetics that take place. A crucial issue is the inevitable catalyst reversible deactivation, consequence of both, coke (by-product) deposition on the catalyst surface (external) and inside the catalytic zeolite (internal). In order to tackle this problem, two main proposals to evaluate deactivation rate by coking have been extensively applied, both use a probability distribution function called "the negative exponential function"—one of them uses the time that catalyst has been in the reacting stream (named Time-on-Stream), and the other is related to the coke amount on/inside the catalyst (denoted as Coke-on-Catalyst). These two deactivation models can be unified by tracking catalyst activity as function of the decrease on effective diffusivity due to pore occlusion (external) by coke—this situation leads to an increase of Thiele modules and consequently a decrease of the effectiveness factor of each reaction. This tracking of catalyst activity incorporates, implicitly, rates of reaction and transport phenomena taking place in the catalyst pores and is therefore phenomenological rather than statistical. In this work, the activity profiles predicted previously are reproduced at MAT laboratory reactor. The same approach is used to model an industrial riser and the results are in agreement with previous reports.

Dependence of Fluid Catalytic Cracking Unit Performance on H‐Oil Severity, Catalyst Activity, and Coke Selectivity

2020 ◽  
Vol 43 (11) ◽  
pp. 2266-2276
Author(s):  
Dicho Stratiev ◽  
Ivelina Shishkova ◽  
Mihail Ivanov ◽  
Ivan Chavdarov ◽  
Dobromir Yordanov
Keyword(s):  
Catalytic Cracking ◽  
Catalyst Activity ◽  
Fluid Catalytic Cracking ◽  
Unit Performance

scholarly journals Research on Hazardous Waste Removal Management: Identification of the Hazardous Characteristics of Fluid Catalytic Cracking Spent Catalysts

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2289
Author(s):  
Haihui Fu ◽  
Yan Chen ◽  
Tingting Liu ◽  
Xuemei Zhu ◽  
Yufei Yang ◽  
...  
Keyword(s):  
Surface Water ◽  
Hazardous Waste ◽  
Environmental Quality ◽  
Catalytic Cracking ◽  
Petroleum Refining ◽  
Fluid Catalytic Cracking ◽  
Refining Industry ◽  
Spent Catalyst ◽  
Spent Catalysts ◽  
Petroleum Refining Industry

Fluid catalytic cracking (FCC) spent catalysts are the most common catalysts produced by the petroleum refining industry in China. The National Hazardous Waste List (2016 edition) lists FCC spent catalysts as hazardous waste, but this listing is very controversial in the petroleum refining industry. This study collects samples of waste catalysts from seven domestic catalytic cracking units without antimony-based passivation agents and identifies their hazardous characteristics. FCC spent catalysts do not have the characteristics of flammability, corrosiveness, reactivity, or infectivity. Based on our analysis of the components and production process of the FCC spent catalysts, we focused on the hazardous characteristic of toxicity. Our results show that the leaching toxicity of the heavy metal pollutants nickel, copper, lead, and zinc in the FCC spent catalyst samples did not exceed the hazardous waste identification standards. Assuming that the standards for antimony and vanadium leachate are 100 times higher than that of the surface water and groundwater environmental quality standards, the leaching concentration of antimony and vanadium in the FCC spent catalyst of the G set of installations exceeds the standard, which may affect the environmental quality of surface water or groundwater. The quantities of toxic substances in all spent FCC catalysts, except those from G2, does not exceed the standard. The acute toxicity of FCC spent catalysts in all installations does not exceed the standard. Therefore, we exclude “waste catalysts from catalytic cracking units without antimony-based passivating agent passivation nickel agent” from the “National Hazardous Waste List.”

Combined mild hydrocracking and fluid catalytic cracking process for efficient conversion of light cycle oil into high-quality gasoline

Fuel ◽  
2021 ◽  
Vol 292 ◽  
pp. 120364
Author(s):  
Peipei Miao ◽  
Xiaolin Zhu ◽  
Yangling Guo ◽  
Jie Miao ◽  
Mengyun Yu ◽  
...  
Keyword(s):  
Catalytic Cracking ◽  
Fluid Catalytic Cracking ◽  
Light Cycle ◽  
High Quality ◽  
Light Cycle Oil ◽  
Efficient Conversion ◽  
Cycle Oil ◽  
Cracking Process
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