Opening of naphthenic ring in decalin cracking over zeolite catalysts
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摘要: 在小型固定流化床(FFB)装置中研究了Y分子筛与ZSM-5分子筛催化剂上的十氢萘裂化开环反应性能,考察了温度和剂油比对Y分子筛开环反应催化性能的影响。结果表明,十氢萘在分子筛催化剂上通过环烷环开环反应生成丙烷、丙烯、丁烷、丁烯、甲基戊烷和环戊烷、环己烷等非芳烃以及苯、C1~4烷基取代苯等单环芳烃,并通过脱氢缩合反应生成四氢萘、萘、甲基萘和菲、芘等多环芳烃甚至焦炭等。由于扩散和吸附性能的影响,ZSM-5分子筛催化剂的裂化开环反应选择性比Y分子筛催化剂的高,因此,十氢萘环烷环开环与脱氢缩合反应的相对比例(NRO/DHC)在ZSM-5分子筛催化剂上较高。在Y分子筛催化剂上,温度为450~550 ℃、剂油比为3~9,反应温度升高或者剂油比增加,双分子氢转移以及脱氢缩合反应增强,从而导致环烷环开环产物选择性降低。Abstract: Decalin cracking over Y and ZSM-5 zeolites were conducted in a small fixed fluidised bed (FFB) reactor; the effect of temperature and catalyst/oil ratio on the opening of naphthenic ring in decalin cracking over Y zeolite was investigated. The results showed that the products of decalin cracking over zeolite catalysts by naphthenic ring opening involve non-aromatics (propane, propylene, butane, butylenes, methylpenptane, cyclopentane, cyclohexane, etc.) and monocyclic aromatics (benzene, and C1~4 alkyl benzene); polycyclic aromatics (tetrahydronaphthalene, naphthalene, alkyl naphthalene, phenanthrenes, pyrenes, etc.) and even coke may also be formed through dehydrogenation condensation reactions. The selectivity for naphthenic ring opening over ZSM-5 catalyst is higher than that over Y catalyst, due to difference in the diffusion and adsorption of naphthenic hydrocarbon on two catalysts. The relative ratio of naphthenic ring opening to dehydrogenation condensation reactions (NRO/DHC) is higher over ZSM-5 catalyst than that over Y catalyst. Under the conditions of 450~550 ℃, weight hourly space velocity of 10 h-1, and catalyst/oil mass ratio of 3~9, with the increase of the reaction temperature or the catalyst/oil ratio, the bimolecular hydrogen transfer and dehydrogenation condensation are enhanced and as a result, the selectivity to the products from naphthenic ring opening is decreased.
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Key words:
- polycyclic naphthene /
- zeolite catalysts /
- catalytic cracking /
- decalin /
- naphthenic ring opening
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DEWACHTERE N V, SANTAELLA F, FROMENT G F. Application of a single-event kinetic model in the simulation of an industrial riser reactor for the catalytic cracking of vacuum gas oil [J]. Chem Eng Sci, 1999, 54(15/16): 3653-3660. CORMA A, GONZALEZ-ALFARO V, ORCHILLES AV. Decalin and tetralin as probe molecules for cracking and hydrotreating the light cycle oil[J]. J Catal, 2001, 200(1): 34-44. AL-SABAWI M, de LASA H. Modeling thermal and catalytic conversion of decalin under industrial FCC operating conditions[J]. Chem Eng Sci, 2010, 65(2): 626-644. 唐津莲, 许友好, 汪燮卿. 全氢菲在分子筛催化剂上环烷环开环反应的研究[J]. 燃料化学学报, 2012, 40(6): 721-726. (TANG Jin-lian, XU You-hao, WANG Xie-qing. Naphthenic ring opening of perhydrophenanthrene over zeolite catalysts [J]. Journal of Fuel Chemistry and Technology, 2012, 40(6): 721-726.) AL-KHATTAF S, de LASA H. Catalytic cracking of cumene in a riser simulator: A catalyst activity decay model[J]. Ind Eng Chem Res, 2001, 40(23): 5398-5404. BURRIESCI N, VALENTE S, OTTANR, CIMINO G, ZIPELLI C. Utilization of zeolites in spinach growing[J]. Zeolites, 1984, 4(1): 5-8.
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