Effect of CO Combustion Promoters on Combustion Air Partition in FCC under Nearly Complete Combustion

doi:10.1016/S1004-9541(14)60078-1

Abstract

Abstract: With CO combustion promoters, the role of combustion air flow rate for concerns of economics and control is important. The combustion air is conceptually divided to three parts: the air consumed by coke burning, the air consumed by CO combustion and the air unreacted. A mathematical model of a fluid catalytic cracking (FCC) unit, which includes a quantitative correlation of CO heterogeneous combustion and the amount of CO combustion promoters, is introduced to investigate the effects of promoters on the three parts of combustion air. The results show that the air consumed by coke burning is almost linear to combustion air flow rate, while the air consumed by CO combustion promoters tends to saturate as combustion air flow rate increases, indicating that higher air flow rate can only be used as a manipulated variable to control the oxygen content for an economic concern.

Key words: fluid catalytic cracking unit, CO combustion promoters, combustion air partition

摘要： With CO combustion promoters, the role of combustion air flow rate for concerns of economics and control is important. The combustion air is conceptually divided to three parts: the air consumed by coke burning, the air consumed by CO combustion and the air unreacted. A mathematical model of a fluid catalytic cracking (FCC) unit, which includes a quantitative correlation of CO heterogeneous combustion and the amount of CO combustion promoters, is introduced to investigate the effects of promoters on the three parts of combustion air. The results show that the air consumed by coke burning is almost linear to combustion air flow rate, while the air consumed by CO combustion promoters tends to saturate as combustion air flow rate increases, indicating that higher air flow rate can only be used as a manipulated variable to control the oxygen content for an economic concern.

关键词: fluid catalytic cracking unit, CO combustion promoters, combustion air partition

WANG Rui, LUO Xionglin, XU Feng. Effect of CO Combustion Promoters on Combustion Air Partition in FCC under Nearly Complete Combustion[J]. Chin.J.Chem.Eng., 2014, 22(5): 531-537.

王锐, 罗雄麟, 许锋. Effect of CO Combustion Promoters on Combustion Air Partition in FCC under Nearly Complete Combustion[J]. Chinese Journal of Chemical Engineering, 2014, 22(5): 531-537.

References

1 McFarlane, R.C., Reineman, R.C., Bartee, J.F., Georgakis, C., "Dynamic simulator for a model IV fluid catalytic cracking unit", Computers & Chemical Engineering, 17 (3), 275-300 (1993).

2 Lee, E., Groves, Jr.F.R., "Mathematical model of the fluidized bed catalytic cracking plant", Transactions, 2 (3), 219-236 (1985).

3 Arbel, A., Huang, Z., Rinard, I.H., Shinnar, R., Sapre, A.V., "Dynamic and control of fluidized catalytic crackers. 1. Modeling of the current generation of FCC’s", Industrial & Engineering Chemistry Research, 34 (4), 1228-1243 (1995).

4 Ali, H., Rohani, S., Corriou, J.P., "Modelling and control of a riser type fluid catalytic cracking (FCC) unit", Chem. Eng. Res. Des., 75 (4), 401-412 (1997).

5 Ellis, R.C., Li, X., Riggs, J.B., "Modeling and optimization of a model IV fluidized catalytic cracking unit", AIChE Journal, 44 (9), 2068-2079 (1998).

6 Arandes, J.M., Azkoiti, M.J., Bilbao, J., de Lasa, H.I., "Modelling FCC units under steady and unsteady state conditions", The Canadian Journal of Chemical Engineering, 78 (1), 111-123 (2000).

7 Han, I.S., Chung, C.B., "Dynamic modeling and simulation of a fluidized catalytic cracking process. Part i: Process modeling", Chemical Engineering Science, 56 (5), 1951-1971 (2001).

8 Secchi, A.R., Santos, M.G., Neumann, G.A., Trierweiler, J.O., "A dynamic model for a FCC UOP stacked converter unit", Computers & Chemical Engineering, 25 (4-6), 851-858 (2001).

9 Fernandes, J.L., Verstraete, J.J., Pinheiro, C.I.C., Oliveira, N.M.C., Ribeiro, F.R., "Dynamic modelling of an industrial R2R FCC unit", Chemical Engineering Science, 62 (4), 1184-1198 (2007).

10 Fernandes, J.L., Pinheiro, C.I.C., Oliveira, N.M.C., Inverno, J., Ribeiro, F.R., "Model development and validation of an industrial UOP fluid catalytic cracking unit with a high-efficiency regenerator", Industrial & Engineering Chemistry Research, 47 (3), 850-866 (2008).

11 Gao, J.S., Xu, C.M., Yang, G.H., Guo, Y.C., Lin, W.Y., "Numerical simulation on gas-solid two-phase turbulent flow in FCC riser reactors (I) Tubulent gas-solid flow-reaction model", Chin. J. Chem. Eng., 6 (1), 12-20 (1998).

12 Gao, J.S., Xu, C.M., Yang, G.H., Guo, Y.C., Wang, X.L., "Numerical simulation on gas-solid two-phase turbulent flow in FCC riser reactors (II) Numerical simulation on the gas-solid two-phase turbulent flow", Chin. J. Chem. Eng., 6 (1), 21-28 (1998).

13 Cristea, M.V., Agachi, S.P., Marinoiu, V., "Simulation and model predictive control of a UOP fluid catalytic cracking unit", Chemical Engineering and Processing: Process Intensification, 42 (2), 67-91 (2003).

14 Grosdidier, P., Mason, A., Aitolahti, A., Heinonen, P., Vanhamäki, V., "FCC unit reactor-regenerator control", Computers & Chemical Engineering, 17 (2), 165-179 (1993).

15 Hovd, M., Skogestad, S., "Procedure for regulatory control structure selection with application to the FCC process", AIChE Journal, 39 (12), 1938-1953 (1993).

16 Arbel, A., Rinard, I.H., Shinnar, R., "Dynamics and control of fluidized catalytic crackers. 3. Designing the control system: Choice of manipulated and measured variables for partial control", Industrial & Engineering Chemistry Research, 35 (7), 2215-2233 (1996).

17 Alvarez-Ramirez, J., Valencia, J., Puebla, H., "Multivariable control configurations for composition regulation in a fluid catalytic cracking unit", Chemical Engineering Journal, 99 (3), 187-201 (2004).

18 Loeblein, C., Perkins, J., "Structural design for on-line process optimization: II. Application to a simulated FCC", AIChE Journal, 45 (5), 1030-1040 (1999).

19 Han, I.S., Riggs, J.B., Chung, C.B., "Modeling and optimization of a fluidized catalytic cracking process under full and partial combustion modes", Chemical Engineering and Processing: Process Intensification, 43 (8), 1063-1084 (2004).

20 Zanin, A.C., de Gouvea, M.T., Odloak, D., "Integrating real-time optimization into the model predictive controller of the FCC system", Control Engineering Practice, 10 (8), 819-831 (2002).

21 Pinheiro, C.I.C., Fernandes, J.L., Domingues, L., Chambel, A.J.S., Graca, I., Oliveira, N.M.C., Cerqueira, H.S., Ribeiro, F.R., "Fluid catalytic cracking (FCC) process modeling, simulation, and control", Industrial & Engineering Chemistry Research, 51 (1), 1-29 (2012).

22 Morley, K., de Lasa, H.I., "On the determination of kinetic parameters for the regeneration of cracking catalyst", The Canadian Journal of Chemical Engineering, 65 (5), 773-777 (1987).

23 Morley, K., de Lasa, H. I., "Regeneration of cracking catalyst influence of the homogeneous CO postcombustion reaction", The Canadian Journal of Chemical Engineering, 66 (3), 428-432 (1988).

24 Fernandes, J.L., Pinheiro, C.I.C., Oliveira, N.M.C., Inverno, J., Ribeiro, F.R., "Closed-loop dynamic behavior of an industrial high-efficiency FCC unit", In: 16th Mediterranean Conference on Control Automation, Sauter, D., ed., Institute of Electrical and Electronics Engineers, Ajaccio, France, 1829-1834 (2008).

25 Luo, X.L., "Dynamic modeling and operation analysis of FCCU with high efficiency regenerator", Ph. D. Thesis，China University of Petroleum, Beijing (1997). (in Chinese)

26 Wang, R., Luo, X.L., Xu, F., "Multiple steady states of FCCU with varying CO concentration", CIESC Journal, 64 (8), 2930-2937 (2013). (in Chinese)

27 Xu, C.M., Lin, S.X., Yang, G.H., "Determination of CO₂/CO in dense bed during cracking catalyst regeneration", Journal of the University of Petroleum, China: Natural Science Edition, 14 (6), 84-93(1990). (in Chinese)

28 Lin, S.X., Petroleum Refining Engineering, 2nd edition, Petroleum Industry Press, Beijing (1988). (in Chinese)

29 Wei, F., Lin, S.X., Yang, G.H., "Kinetic study of gas-phase CO slow oxidation", Journal of the University of Petroleum, China: Natural Science Edition, 12 (4-5), 110-116(1988). (in Chinese)

30 Liu, D., Sun, P., Liu, X., Wang, J., Ma, F., Zhao, J., "The activity determination of Pt/Al₂O₃ CO-promoted catalyst used in regenerator of catalytic cracking (I) The kinetics of CO oxidation over new Pt/Al₂O₃ promoter", Chemical Engineering (China), 25 (3), 18-22 (1997). (in Chinese)

31 Liu, D., Liu, X., Wang, J., Sun, P., He, W., Zhao, J., "The activity determination of Pt/Al₂O₃ CO-promoted catalyst used in regenerator of catalytic cracking (II) The determination and simulation of equilibrium activity", Chemical Engineering (China), 25 (3), 23-26 (1997). (in Chinese)

32 Chen, J.W., Catalytic Cracking Technology and Engineering, 2nd edition, SINOPEC Press, Beijing (2005). (in Chinese)

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