Influence of Feed Injection on Hydrodynamic Behavior in FCC Riser

Abstract

Abstract: This paper studies the influence of feed injection on the hydrodynamic behavior of fluid
catalytic cracking riser reactors. Experiments were conducted in a cold model of 186 mm ID
with two oppositely inclined secondary air feed nozzles. The flow structure was determined
by means of the axial static pressure measurements and local radial optic fiber probe
measurements on different levels with emphasis on the sections downstream of the secondary
injection. The measurements reveal that the secondary injection plays a crucial role on
riser hydrodynamics. Just above the secondary injection, the flow and mixing are strongly
affected, while below the secondary injection the effect is weak. The radial profile just
downstream of secondary injection demonstrates wavy features. The effective region of
secondary injection could be estimated by the axial pressure gradient profiles and/or the
radial profiles of local solids velocity and density.

Key words: fluid catalytic cracking, riser reactor, feed injection region, flow structure

摘要： This paper studies the influence of feed injection on the hydrodynamic behavior of fluid
catalytic cracking riser reactors. Experiments were conducted in a cold model of 186 mm ID
with two oppositely inclined secondary air feed nozzles. The flow structure was determined
by means of the axial static pressure measurements and local radial optic fiber probe
measurements on different levels with emphasis on the sections downstream of the secondary
injection. The measurements reveal that the secondary injection plays a crucial role on
riser hydrodynamics. Just above the secondary injection, the flow and mixing are strongly
affected, while below the secondary injection the effect is weak. The radial profile just
downstream of secondary injection demonstrates wavy features. The effective region of
secondary injection could be estimated by the axial pressure gradient profiles and/or the
radial profiles of local solids velocity and density.

关键词: fluid catalytic cracking;riser reactor;feed injection region;flow structure

SUN Guogang, SHI Mingxian. Influence of Feed Injection on Hydrodynamic Behavior in FCC Riser[J]. .

孙国刚, 时铭显. 喷嘴进料对催化裂化提升管流动行为的影响[J]. CIESC Journal.

References

[1] Wang, X.S., Gibbs, B.M., "Hydrodynamics of a circulating fiuidized bed with secondary
air injection", In: Circulating Fluidized Bed Technology Ⅲ, Basu, P., Horio, M.,
Hasatani,M., Eds., Pergamon Press, Oxford, 225-230 (1991).
[2] Arena, U., Marzocchella, A., Bruzzi, V., Massimilla, L.,"Mixing between a gas-solid
suspension flowing in a riser and a lateral gas stream", In: Circulating Fluidized Bed
Technology Ⅳ, Avidan, A., Ed., AIChE , New York, 545-550 (1993).
[3] Marzocchella, A., Arena, U., "Hydrodynamics of a circulating fluidized bed operated
with different secondary air injection devices", Powder Technol., 87, 185-191 (1996).
[4] Cho, Y.J., Namkung, W., Kim, S.D., Park, S., "Effect of secondary air injection on
axial solid holdup distribution in a circulating fiuidized bed", J. Chem. Eng. Japan, 27
(2),158-164 (1994).
[5] Aguillon, J., Shakourzadeh, K., Guigon, P., Large, J.F.,"Hydrodynamic behaviour of
circulating fiuidized bed with secondary air injection", In:Circulating Fluidized Bed
Technology V, Beijing, DGS4 (1996).
[6] Zijlma, G.J., Gerritsen, A.W., Van Bleek, C.M., "Influence of secondary air injection
on solids distribution and circulation rate in a CFB", In:Circulating Fluidized Bed
Technology Ⅵ, Werther, J., Ed., DECHEMA e.V., 27-32 (1999).
[7] 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): Turbulent gas-solid flow
reaction model", Chinese J. Chem. Eng., 6 (1), 12-20 (1998).
[8] Gao, J.S., Xu, C.M., Lin, S.X., 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", Chinese J. Chem.Eng., 6 (1), 21-28 (199S).
[9] Gao, J.S., "Numerical simulation on the flow, heat-transfer and reaction in the
catalytic cracking riser reactors", Ph.D. Thesis, University of Petroleum, Beijing (1997).
(in Chinese)
[10] Fan, Y.P., "Gas-solid two-phase flow in FCC riser", Ph. D.Thesis, University of
Petroleum, Beijing (2000). (in Chinese)
[11] Fan, Y.P., Ye, S., Lu, C.X., Sun, G., G., Shi, M.X., "Gassolid two-phase flow in FCC
riser", AIChE J., 48 (9),1869-1887 (2002).
[12] Sun, G.G., Chao, Z.X., Fan, Y.P., Shi, M.X., "Hydrodynamic behavior in the bottom
region of a cold FCC riser",In: Circulating Fluidized Bed Technology Ⅵ, Werther, J.,Ed,
DECHEMA e.V., 179-184 (1999).
[13] Li, Y., Kwauk, M., "The dynamics of fast fiuidization", In:Fluidization, Grace, J. R.,
Matsen, J. M., Eds., Plenum Press, Oxford, 537-544 (1980).

[1]	Sheng CHEN, Mengke WANG, Bona LU, Xiufeng LI, Cenfan LIU, Mengxi LIU, Yiping FAN, Chunxi LU. CFD investigation of effects of feedstock oil vaporization on FCC cracking reaction and coking [J]. CIESC Journal, 2022, 73(7): 2982-2995.
[2]	Xiaogang SHI, Chengxiu WANG, Jinsen GAO, Xingying LAN. Numerical simulation study on influence of mesoscale structure in riser reactor [J]. CIESC Journal, 2022, 73(6): 2708-2721.
[3]	Jun XU, Zhifeng WANG, Kaijun HOU, Yongfu GAO, Yiping FAN, Chunxi LU. Experimental and theoretical study on gas-solid flow characteristics in feedstock injection zone of FCC riser with double-layer nozzles [J]. CIESC Journal, 2021, 72(8): 4019-4029.
[4]	Jun XU, Yiping FAN, Xiaojie QIAN, Zihan YAN, Chunxi LU. Theoretical analysis of motion-diffusion characteristics in feed injection zone of FCC riser [J]. CIESC Journal, 2020, 71(4): 1450-1459.
[5]	FAN Yiping, LU Chunxi. Multiphase flow characteristics and structural optimization in feed injection zone of FCC riser [J]. CIESC Journal, 2018, 69(1): 249-258.
[6]	BAI Dehong, ZONG Yuan, ZHAO Ling. Computational fluid dynamics assisted design of cracking coils [J]. CIESC Journal, 2017, 68(2): 660-669.
[7]	LIU Yingjie, YANG Jihe, LAN Xingying, GAO Jinsen. Numerical study on RFCC chemical stripping process [J]. CIESC Journal, 2016, 67(8): 3244-3250.
[8]	WANG Min, WU Yingya, LAN Xingying, GAO Jinsen. Effect of terminator injection on catalytic cracking reactions in FCC riser [J]. CIESC Journal, 2016, 67(8): 3191-3201.
[9]	CHEN Sheng, FAN Yiping, YAN Zihan, LI Fei, WANG Wei, LU Chunxi. CFD simulation of novel fluidizer technology in feedstock injection zone of FCC riser [J]. CIESC Journal, 2016, 67(8): 3179-3190.
[10]	FAN Chunling, JIN Ningde, CHEN Xiuting, DOU Fuxiang, GAO Zhongke. Two-phase flow structure in multi-scale complexity entropy causality plane [J]. CIESC Journal, 2015, 66(4): 1301-1309.
[11]	LI Jun, LUO Guohua, WEI Fei. A novel multi-layer and multi-zone redox FCC regenerator design for removing NO_x gas system [J]. CIESC Journal, 2014, 65(7): 2426-2436.
[12]	JIN Nan, WANG Gang, XU Chunming, GAO Jinsen. Predicting vaporization of feedstock in zoning catalytic cracking by UNIFAC model [J]. CIESC Journal, 2014, 65(7): 2710-2716.
[13]	WANG Jiangang, ZHANG Yanhong, BAI Zhaoyuan, HUANG Cong, WANG Hualin. Effects of inlet size on separation flow field inside hydrocyclone [J]. CIESC Journal, 2014, 65(1): 205-212.
[14]	SUI Shuhui1，2. Development and commercial application of SOx transfer addictive in FCC flue gas [J]. Chemical Industry and Engineering Progree, 2013, 32(05): 1194-1199.
[15]	XU Qiaoqi, JI Zhongli, YANG Liang. Performance assessment of high temperature flue gas on-line particle size analyzer [J]. CIESC Journal, 2012, 63(11): 3506-3512.