碳五烷烃裂解制低碳烯烃反应性能的分析

doi:10.11949/0438-1157.20210488

摘要/Abstract

摘要：

考察了碳五烷烃的热裂解和催化裂解反应性能，发现正戊烷和异戊烷的裂解反应产物存在差异；进一步分析了正戊烷和异戊烷的裂解反应机理，以及裂解生成低碳烯烃和甲烷的区别。结果表明，在热裂解条件下，正戊烷的（乙烯+丙烯）选择性高于异戊烷，异戊烷的丁烯和甲烷选择性高于正戊烷；650℃时，正戊烷和异戊烷的热裂解产品中（乙烯+丙烯）、丁烯、甲烷的选择性分别为37.48%、7.23%、6.75%和19.57%、25.16%、9.36%。而在催化裂解条件下，异戊烷的（乙烯+丙烯）、丁烯、甲烷选择性均高于正戊烷；650℃时，正戊烷和异戊烷的催化裂解产品中（乙烯+丙烯）、丁烯、甲烷的选择性分别为37.16%、9.11%、7.80%和47.70%、14.45%、13.79%。此外，发现在高温裂解条件下异构烷烃比正构烷烃容易裂解生成丁烯和甲烷。

关键词: 烷烃, 催化裂解, 热解, 低碳烯烃, 甲烷

Abstract:

The thermal cracking and catalytic cracking reaction performance of C₅ alkanes were investigated, and the cracking reaction products of n-pentane and isopentane were found to be different. Furthermore, the pyrolysis mechanism of n-pentane and isopentane was analyzed, and the difference between the cracking of n-pentane and isopentane to produce light olefins and methane was revealed. The results showed that under thermal pyrolysis conditions, the selectivity of (ethylene + propylene) of n-pentane was higher than that of isopentane, the selectivities of isopentane thermal pyrolysis products butene and methane were higher than that of n-pentane. At 650℃, the selectivities of n-pentane and isopentane thermal pyrolysis products including (ethylene + propylene), butene, and methane were 37.48%, 7.23%, 6.75% and 19.57%, 25.16%, 9.36%, respectively. However, under catalytic pyrolysis conditions, the selectivities of isopentane catalytic pyrolysis products (ethylene + propylene), butene, and methane were higher than that of n-pentane. At 650℃, the selectivities of n-pentane and isopentane thermal pyrolysis products including (ethylene + propylene), butene, and methane were 37.16%, 9.11%, 7.80% and 47.70%, 14.45%, 13.79%, respectively. In addition, it was found that isoalkanes are easier to crack to butene and methane than n-alkanes under high temperature cracking conditions.

Key words: alkane, catalytic pyrolysis, pyrolysis, light olefins, methane

中图分类号:

TE 624.4

刘美佳,王刚,张忠东,许顺年,王皓,党法璐,何盛宝. 碳五烷烃裂解制低碳烯烃反应性能的分析[J]. 化工学报, 2021, 72(10): 5172-5182.

Meijia LIU,Gang WANG,Zhongdong ZHANG,Shunnian XU,Hao WANG,Falu DANG,Shengbao HE. Analysis of reaction performance of high efficient pyrolysis of C₅ alkanes to light olefins[J]. CIESC Journal, 2021, 72(10): 5172-5182.

图/表 13

表1 催化裂解反应使用的分子筛性质

Table 1 Properties of zeolites used in catalytic pyrolysis

拓扑结构	硅铝比	比表面积/(m²/g)	微孔体积/(cm³/g)	孔径 /nm	弱酸量/(mmol/g)	强酸量/(mmol/g)	总酸量/(mmol/g)
MFI	120	397.520	0.141	0.520	0.116	0.102	0.218

图1 微型固定床实验装置

Fig.1 Micro fixed bed experiment apparatus

图2 正戊烷和异戊烷的裂解反应转化率

Fig.2 Cracking conversion of n-pentane and isopentane

图3 正戊烷和异戊烷热裂解和催化裂解的产物分布

Fig.3 Product distribution of thermal pyrolysis and catalytic pyrolysis of n-pentane and isopentane

图4 正戊烷的自由基裂解反应机理

Fig.4 Mechanism of free radical pyrolysis of n-pentane

图5 正戊烷和异戊烷热裂解的产物分布

Fig.5 Product distribution of thermal pyrolysis of n-pentane and isopentane

图6 异戊烷的自由基裂解反应机理

Fig.6 Mechanism of free radical pyrolysis of isopentane

图7 正戊烷的正碳离子裂解反应机理

Fig.7 Pyrolysis mechanism of carbocation of n-pentane

图8 正戊烷和异戊烷催化裂解的产物分布

Fig.8 Product distribution of catalytic pyrolysis of n-pentane and isopentane

图9 异戊烷的正碳离子裂解反应机理

Fig.9 Pyrolysis mechanism of carbocation of isopentane

图10 C5烷烃热裂解与催化裂解反应中低碳烯烃的选择性

Fig.10 Selectivity of light olefins in thermal pyrolysis and catalytic pyrolysis of C5 alkanes

表2 正构烷烃和异构烷烃裂解反应结果对比

Table 2 Comparison of cracking reaction results of n-alkanes and isoalkanes

碳数		原料	转化率/%	甲烷选择性/%	乙烯选择性/%	丙烯选择性/%	丁烯选择性/%	文献
热裂解	C₅	正戊烷	77.90	11.94	43.13	23.88	10.14	[8]
	C₅	2-甲基丁烷	78.20	15.47	20.72	25.06	25.83	[8]
	C₇	正庚烷	87.80	8.09	54.44	19.70	11.16	[8]
		2-甲基己烷	91.50	12.02	30.27	25.25	18.36
		3-甲基己烷	94.30	12.94	31.81	22.27	15.38
	C₈	正辛烷	92.70	9.17	46.60	18.34	11.33	[8]
		3-甲基庚烷	94.70	10.67	38.54	20.17	15.42
		2,3-二甲基己烷	98.60	16.02	17.65	26.88	16.53
催化裂解	C₈	正辛烷	8.66	9.29	—	—	52.47	[11]
		3-甲基庚烷	7.23	23.25	—	—	61.36
		2,5-二甲基庚烷	6.04	33.93	—	—	72.34
	C₈	正辛烷	96.66	—	—	—	9.22	[9]
	C₈	异辛烷	61.15	—	—	—	15.14	[9]

图11 C5烷烃热裂解与催化裂解反应中甲烷选择性

Fig.11 Methane selectivity in thermal pyrolysis and catalytic pyrolysis of C5 alkanes

参考文献 30

1	孙丽丽. 新型炼油厂的技术集成与构建[J]. 石油学报(石油加工), 2020, 36(1): 1-10.
	Sun L L. Technology integration and construction of new refineries[J]. Acta Petrolei Sinica (Petroleum Processing Section), 2020, 36(1): 1-10.
2	Corma A, Corresa E, Mathieu Y, et al. Crude oil to chemicals: light olefins from crude oil[J]. Catalysis Science & Technology, 2017, 7(1): 12-46.
3	汪燮卿, 舒兴田. 重质油裂解制轻烯烃[M]. 北京: 中国石化出版社, 2015.
	Wang X Q, Shu X T. Heavy Oil Catalytic Cracking to Olefins[M]. Beijing: China Petrochemical Press, 2015.
4	Wang G, Xu C M, Gao J S. Study of cracking FCC naphtha in a secondary riser of the FCC unit for maximum propylene production[J]. Fuel Processing Technology, 2008, 89(9): 864-873.
5	Li C Y, Yang C H, Shan H H. Maximizing propylene yield by two-stage riser catalytic cracking of heavy oil[J]. Industrial & Engineering Chemistry Research, 2007, 46(14): 4914-4920.
6	Hou X, Qiu Y, Zhang X W, et al. Analysis of reaction pathways for n-pentane cracking over zeolites to produce light olefins[J]. Chemical Engineering Journal, 2017, 307: 372-381.
7	Thivasasith A, Maihom T, Pengpanich S, et al. Nanocavity effects of various zeolite frameworks on n-pentane cracking to light olefins: combination studies of DFT calculations and experiments[J]. Physical Chemistry Chemical Physics, 2019, 21(40): 22215-22223.
8	Zámostný P, Bělohlav Z, Starkbaumová L, et al. Experimental study of hydrocarbon structure effects on the composition of its pyrolysis products[J]. Journal of Analytical and Applied Pyrolysis, 2010, 87(2): 207-216.
9	张睿, 刘贵丽, 王亚东, 等. 轻烃催化裂解制低碳烯烃反应规律与原料特征化[J]. 化工学报, 2016, 67(8): 3387-3393.
	Zhang R, Liu G L, Wang Y D, et al. Reaction behaviors and feed characterization of light hydrocarbon catalytic pyrolysis for production of light olefins[J]. CIESC Journal, 2016, 67(8): 3387-3393.
10	Kissin Y V. Chemical mechanisms of catalytic cracking over solid acidic catalysts: alkanes and alkenes[J]. Catalysis Reviews, 2001, 43(1/2): 85-146.
11	李福超, 袁起民, 魏晓丽. 烃分子结构对其催化裂解反应性能的影响[J]. 石油学报(石油加工), 2020, 36(4): 661-666.
	Li F C, Yuan Q M, Wei X L. Effects of molecular structure on hydrocarbon catalytic cracking performance[J]. Acta Petrolei Sinica (Petroleum Processing Section), 2020, 36(4): 661-666.
12	魏晓丽, 张久顺, 毛安国, 等. 石脑油催化裂解生成甲烷的影响因素探析[J]. 石油炼制与化工, 2014, 45(3): 1-5.
	Wei X L, Zhang J S, Mao A G, et al. Investigation on influence factors of methane formation in naphtha catalytic cracking[J]. Petroleum Processing and Petrochemicals, 2014, 45(3): 1-5.
13	李福超, 张久顺, 袁起民. 正辛烷热裂化和催化裂化生成甲烷反应机理[J]. 燃料化学学报, 2014, 42(6): 697-703.
	Li F C, Zhang J S, Yuan Q M. Mechanism of methane formation in thermal and catalytic cracking of n-octane[J]. Journal of Fuel Chemistry and Technology, 2014, 42(6): 697-703.
14	李福超, 袁起民, 王亚敏, 等. 3-甲基庚烷热裂化和催化裂化甲烷生成机理[J]. 石油学报(石油加工), 2015, 31(4): 853-860.
	Li F C, Yuan Q M, Wang Y M, et al. Mechanism of methane formation in thermal and catalytic cracking of 3-methylheptane[J]. Acta Petrolei Sinica (Petroleum Processing Section), 2015, 31(4): 853-860.
15	李福超, 袁起民, 张久顺. 2,5-二甲基己烷热裂化和催化裂化生成甲烷的机理研究[J]. 石油炼制与化工, 2014, 45(12): 1-5.
	Li F C, Yuan Q M, Zhang J S. Study on methane formation in thermal and catalytic cracking of 2,5-dimethylhexane[J]. Petroleum Processing and Petrochemicals, 2014, 45(12): 1-5.
16	Tian Y J, Zhang B F, Liang H R, et al. Synthesis and performance of pillared HZSM-5 nanosheet zeolites for n-decane catalytic cracking to produce light olefins[J]. Applied Catalysis A: General, 2019, 572: 24-33.
17	Sundberg J, Standl S, von Aretin T, et al. Optimal process for catalytic cracking of higher olefins on ZSM-5[J]. Chemical Engineering Journal, 2018, 348: 84-94.
18	Bortnovsky O, Sazama P, Wichterlova B. Cracking of pentenes to C₂—C₄ light olefins over zeolites and zeotypes: role of topology and acid site strength and concentration[J]. Applied Catalysis A: General, 2005, 287(2): 203-213.
19	Altynkovich E O, Potapenko O V, Sorokina T P, et al. Butane-butylene fraction cracking over modified ZSM-5 zeolite[J]. Petroleum Chemistry, 2017, 57(3): 215-221.
20	马通, 耿祖豹, 李冰, 等. 不同模板制备ZSM-5分子筛的酸性特征及催化裂解性能差异[J]. 化工学报, 2016, 67(8): 3374-3379.
	Ma T, Geng Z B, Li B, et al. Difference of acid characters and catalytic cracking performance between ZSM-5 zeolites synthesized with various templates[J]. CIESC Journal, 2016, 67(8): 3374-3379.
21	Potapenko O V, Doronin V P, Sorokina T P, et al. A study of intermolecular hydrogen transfer from naphthenes to 1-hexene over zeolite catalysts[J]. Applied Catalysis A: General, 2016, 516: 153-159.
22	刘美佳, 王刚, 张忠东, 等. C₅烃催化裂解过程中氢转移反应的研究[J]. 燃料化学学报, 2021, 49(1): 104-112.
	Liu M J, Wang G, Zhang Z D, et al. Study on hydrogen transfer reaction in C₅ hydrocarbons catalytic pyrolysis[J]. Journal of Fuel Chemistry and Technology, 2021, 49(1): 104-112.
23	Corma A, González-Alfaro V, Orchillés A V. The role of pore topology on the behaviour of FCC zeolite additives [J]. Applied Catalysis: A General, 1999, 187(2): 245-254.
24	Hou X, Ni N, Wang Y, et al. Roles of the free radical and carbenium ion mechanisms in pentane cracking to produce light olefins[J]. Journal of Analytical and Applied Pyrolysis, 2019, 138: 270-280.
25	Zhang R, Wang Z X, Liu H Y, et al. Thermodynamic equilibrium distribution of light olefins in catalytic pyrolysis[J]. Applied Catalysis A: General, 2016, 522: 165-171.
26	Fu J, Feng X, Liu Y B, et al. Effect of pore confinement on the adsorption of mono-branched alkanes of naphtha in ZSM-5 and Y zeolites[J]. Applied Surface Science, 2017, 423: 131-138.
27	Haag W O, Dessau R M, Lago R M. Kinetics and mechanism of paraffin cracking with zeolite catalysts[J]. Studies in Surface Science and Catalysis, 1991, 60: 255-265.
28	Krannila H, Haag W O, Gates B C. Monomolecular and bimolecular mechanisms of paraffin cracking: n-butane cracking catalyzed by HZSM-5[J]. Journal of Catalysis, 1992, 135(1): 115-124.
29	Kubo K, Iida H, Namba S, et al. Selective formation of light olefin by n-heptane cracking over HZSM-5 at high temperatures[J]. Microporous and Mesoporous Materials, 2012, 149(1): 126-133.
30	罗渝然. 化学键能数据手册[M]. 北京: 科学出版社, 2005.
	Luo Y R. Handbook of Bond Dissociation Energies[M]. Beijing: Science Press, 2005.

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