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Insight into reaction path and mechanism of catalytic cracking of n-hexane in HZSM-5 zeolites

ZHAI Peng ZHENG Jian ZHANG Jin-yan WANG Huan QIN Yu-cai LIU Hong-hai SONG Li-juan

翟鹏, 郑健, 张锦研, 王焕, 秦玉才, 刘宏海, 宋丽娟. HZSM-5上正己烷酸催化裂解反应路径及机理的探讨[J]. 燃料化学学报. doi: 10.1016/S1872-5813(21)60158-5
引用本文: 翟鹏, 郑健, 张锦研, 王焕, 秦玉才, 刘宏海, 宋丽娟. HZSM-5上正己烷酸催化裂解反应路径及机理的探讨[J]. 燃料化学学报. doi: 10.1016/S1872-5813(21)60158-5
ZHAI Peng, ZHENG Jian, ZHANG Jin-yan, WANG Huan, QIN Yu-cai, LIU Hong-hai, SONG Li-juan. Insight into reaction path and mechanism of catalytic cracking of n-hexane in HZSM-5 zeolites[J]. Journal of Fuel Chemistry and Technology. doi: 10.1016/S1872-5813(21)60158-5
Citation: ZHAI Peng, ZHENG Jian, ZHANG Jin-yan, WANG Huan, QIN Yu-cai, LIU Hong-hai, SONG Li-juan. Insight into reaction path and mechanism of catalytic cracking of n-hexane in HZSM-5 zeolites[J]. Journal of Fuel Chemistry and Technology. doi: 10.1016/S1872-5813(21)60158-5

HZSM-5上正己烷酸催化裂解反应路径及机理的探讨

doi: 10.1016/S1872-5813(21)60158-5
详细信息
  • 中图分类号: O643

Insight into reaction path and mechanism of catalytic cracking of n-hexane in HZSM-5 zeolites

Funds: The project was supported by National Natural Science Foundation of China(No. 21902068, U20A20120), the Sponsored by CNPC Innovation Found (2020D-5007-0401), Scientific Research Project of Education Department of Liaoning Province (L2019035)
More Information
  • 摘要: 以正己烷为模型化合物,通过产物分布分析,探讨HZSM-5分子筛上烷烃酸催化裂解反应路径及机理。研究结果表明:反应温度为300 ℃,不存在热裂解过程的条件下,只有基于碳正离子机理的酸催化反应。催化剂裂化活性与B 酸(Brönsted acid)量成正相关。由裂解产物的分布特点,其中丙烯的选择性与催化剂硅铝比和剂油比正相关,而乙烷、乙烯和丙烷的选择性呈负相关性,证实了低酸密度有利于单分子裂解路径的进行。值得注意的是,正己烷直接裂解所得C4产物的总选择性远高于C2产物,结合量化计算,证实正己烷裂解生成的${{\rm{C}}_2}{\rm{H}}_5^ + $碳正离子难以通过氢转移反应生成乙烯和乙烷,而是更倾向于与正己烷分子形成新的碳鎓离子(${{\rm{C}}_8}{\rm{H}}_{19}^ + $),继续发生裂解反应生成更多C4产物,揭示了轻烃催化裂解产物中乙烯选择性低的理论本质。综上可知,通过改变催化剂酸密度和剂油比,可实现反应路径的控制,从而调控轻烃酸催化裂解产物的选择性。本研究结果可为石脑油催化裂解催化剂和工艺开发提供重要的理论支撑。
  • Figure  1  XRD patterns of HZSM-5 zeolites with different Si/Al ratio

    Figure  2  N2 adsorption-desorption isotherms of HZSM-5 zeolites with different Si/Al ratio

    Figure  3  NH3-TPD profiles of HZSM-5 zeolites with different Si/Al ratios

    Figure  4  Py-FTIR spectra of HZSM-5 zeolites with different Si/Al ratios (A: desorption at 150 ℃ B: desorption at 400 ℃)

    Figure  6  The change of the distribution of typical products of n-hexane catalytic cracking at 300 ℃ as a function of Si/Al ratios and catalyst to oil ratio (A: ethane, B: ethylene, C: propane, D: propylene)

    Figure  5  Products Distribution of n-hexane catalytic cracking at 300 ℃ for different catalyst to oil ratios on HZSM-5 zeolites with different Si/Al ratios (A: HZSM-5(C) B: HZSM-5(B) C: HZSM-5(A); the bar graph shows the molar product selectivity, and the line graph shows the n-hexane conversion)

    Figure  7  Structure diagram of model process of adsorption and protonation of ethylene and propylene on B acidic site of HZSM-5 zeolite (top) and process energy barrier diagram (bottom)

    Table  1  Structure properties of HZSM-5 zeolites with Si/Al ratios

    SampleSBET (m2·g−1)Smicro m2·g−1Sexter m2·g−1Vtotal cm3·g−1Vmicro cm3·g−1(Vtotal-Vmicro) cm3·g−1
    HZSM-5(A)3302201100.190.120.08
    HZSM-5(B)3122051070.210.110.11
    HZSM-5(C)3122041080.220.120.10
    下载: 导出CSV

    Table  2  Acidic properties of HZSM-5 zeolites with different Si/Al ratios

    SampleSi/AlaLCb (mmol·g−1)HCb (mmol·g−1)T acid sites (mmol·g−1)L acidc (mmol·g−1)B acidc (mmol·g−1)B/L
    HZSM-5(A)28.81.556.618.160.965.886.13
    HZSM-5(B)86.40.492.032.520.561.803.21
    HZSM-5(C)151.60.151.401.550.320.672.09
    [a] Zeolite Si/Al ratio measured by XRF. [b] Zeolite acid amounts were derived from NH3-TPD, with the low temperature part corresponding to weak acid sites and the high temperature part ascribed to strong acid sites. [c] Amount of L-acid site and B-acid site were derived from Py-IR.
    下载: 导出CSV
  • [1] WANG P Z, ZHANG W F, ZHU H B, YUAN P, YANG C H, LI C Y, BAO X J. Insights into the reaction pathway of n-butane conversion over HZSM-5 zeolite at low temperature[J]. Appl Catal, A,2019,584:117−135.
    [2] RAHIMI N, KARIMZADEH R. Catalytic cracking of hydrocarbons over modified ZSM-5 zeolites to produce light olefins: A review[J]. Appl. Catal, A,2011,398(1-2):1−17. doi: 10.1016/j.apcata.2011.03.009
    [3] JIANG J L, YANG Y, SONG C, MU D, XU Y, FENG L D. Preparation of hollow ZSM-5 crystals in the presence of polyacrylamide[J]. Microporous Mesoporous Mater,2012,163:11−20. doi: 10.1016/j.micromeso.2012.06.048
    [4] DIAO Z H, WANG L, ZHANG X W, LIU G Z. Catalytic cracking of supercritical n-dodecane over meso-HZSM-5@Al-MCM-41 zeolites[J]. Chem Eng Sci,2015,452−460.
    [5] ZHU X C, WU L L, MAGUSIN P C M M, HENSEN B M E J M. On the synthesis of highly acidic nanolayered ZSM-5[J]. J Catal,2015,327:10−21. doi: 10.1016/j.jcat.2015.04.011
    [6] WANG X N, ZHAO Z, XU C M, DUAN A J, ZHANG L, JIANG G Y. Effects of Light Rare Earth on Acidity and Catalytic Performance of HZSM-5 Zeolite for Catalytic Cracking of Butane to Light Olefins[J]. J Rare Earths,2007,25(3):321−328. doi: 10.1016/S1002-0721(07)60430-X
    [7] SAVAGE P E. Mechanisms and kinetics models for hydrocarbon pyrolysis[J]. J Anal Appl Pyrolysis,2000,54:109−126. doi: 10.1016/S0165-2370(99)00084-4
    [8] YUAN T, ZHANG L D, ZHOU Z Y, XIE M F, YE L L, QI F. Pyrolysis of n-heptane: Experimental and theoretical study[J]. J Phys Chem A,2011,115(9):1593. doi: 10.1021/jp109640z
    [9] MIER D, AGUAYO A T, GAMERO M, GAYUBO A G, BILBAO J. Kinetic Modeling of n-Butane Cracking on HZSM-5 Zeolite Catalyst[J]. Ind Eng Chem Res,2010,49(18):8415−8423. doi: 10.1021/ie1006245
    [10] LIU Mei-jia, WANG Gang, ZHANG Zhong-dong, TIAN Ai-zhen. Study on hydrogen transfer reaction in catalytic cracking of C5 hydrocarbon[J]. J Fuel Chem Technol,2021,49(1):104−112. )
    [11] JANDA A, VLAISAVLJEVICH B, LIN L C, SMIT B, BELL A T. Effects of Zeolite Structural Confinement on Adsorption Thermodynamics and Reaction Kinetics for Monomolecular Cracking and Dehydrogenation of n-Butane[J]. J Amer Chem Soc,2016,138(14):4739−4756. doi: 10.1021/jacs.5b11355
    [12] ZHANG W, WANG P, YANG C, LI C. A Comparative Study of n -Butane Isomerization over H-Beta and H-ZSM-5 Zeolites at Low Temperatures: Effects of Acid Properties and Pore Structures[J]. Catal Lett,2019,149:1017−1025. doi: 10.1007/s10562-019-02683-0
    [13] NIENMIEN V. Kinetic Study of n-Butane Isomerization over Pt-H-Mordenite[C] Aps March Meeting. American Physical Society, 2005.
    [14] CORMA A, ORCHILLES A V. Current views on the mechanism of catalytic cracking[J]. Microporous Mesoporous Mater,2000,35:21−30.
    [15] HOU X, NI N, WANG Y, ZHU W, QIU Y, LIU G Z, ZHAGN X. Roles of the free radical and carbenium ion mechanisms in pentane cracking to produce light olefins[J]. J. Anal. Appl. Pyrolysis,2019,138(MAR.):270−280.
    [16] AFROUKHTEH L N, TARIGHI S, KHONAKDARA H A. Catalytic Cracking of n-Hexane and n-Heptane over ZSM-5 Zeolite: Influence of SiO2/Al2O3 Ratio[J]. Petro Chem,2018,58(5):457−463. doi: 10.1134/S096554411805002X
    [17] SANG Y, LI H. Effect of phosphorus and mesopore modification on the HZSM-5 zeolites for n-decane cracking[J]. J Solid State Chem,2019,271:326−333. doi: 10.1016/j.jssc.2019.01.016
    [18] QAMAR M, AHMED M I, QAMARUDDIN M, ASIF M, SANHOOB M, MURAZA O, KHAN M Y. A Mesopore-Dependent Catalytic Cracking of n-Hexane Over Mesoporous Nanostructured ZSM-5[J]. J Neurosci,2018,18(8):5711.
    [19] SUN Y, MA T, ZHANG L M, SONG Y, SHANG Y S, ZHAI Y L, GONG Y J, DUAN A J. The influence of zoned Al distribution of ZSM-5 zeolite on the reactivity of hexane cracking[J]. Mol Catal,2020,484:110770. doi: 10.1016/j.mcat.2020.110770
    [20] WANG P Z, WANG S Q, YUE Y Y, WANG T H, BAO X J. Effects of acidity and topology of zeolites on the n-alkane conversion at low reaction temperatures[J]. Microporous Mesoporous Mater,2020,292:109748. doi: 10.1016/j.micromeso.2019.109748
    [21] SADRAMELI S M. Thermal/catalytic cracking of liquid hydrocarbons for the production of olefins: A state-of-the-art review II: Catalytic cracking review[J]. Fuel,2016,173:285−297. doi: 10.1016/j.fuel.2016.01.047
    [22] HOU X, QIU Y, ZHANG X J, LIU G J. Analysis of reaction pathways for n-pentane cracking over zeolites to produce light olefins[J]. Chem Eng J,2017,307:372−381. doi: 10.1016/j.cej.2016.08.047
    [23] QIN Y C, GAO X H, PEI T T, ZHENG L G, WANG L, MO Z S, SONG L J. Adsorption and catalytic conversion of thiophene on Y-type zeolites modified with rare-earth metal ions[J]. J Fuel Chem Technol,2013,41(7):90−96.
    [24] JIA W M, QIN Y C, ZHANG L, MO Z S, SONG L J, SUN Z L. Study on accessibility and catalytic activity of Y zeolite modified by Ce-species[J]. Pet Process Petrochem,2017,48(6):14−19.
    [25] ZHENG A, HUANG S J, LIU S B, DENG F. Acid properties of solid acid catalysts characterized by solid-state 31P NMR of adsorbed phosphorous probe molecules[J]. Phys Chem Chem Phys,2011,13(33):14889−14901. doi: 10.1039/c1cp20417c
    [26] XUE Z, ZHANG T, MA J, MIAO H, FAN W, ZHANG Y, LI R. Accessibility and catalysis of acidic sites in hierarchical ZSM-5 prepared by silanization[J]. Microporous Mesoporous Mater,2012,151:271−276. doi: 10.1016/j.micromeso.2011.10.026
    [27] NA J, LIU G, ZHOU T, DING G, HU S, WANG L. Synthesis and catalytic performance of ZSM-5/MCM-41 zeolites with varying mesopore size by surfactant-directed recrystallization[J]. Catal Lett,2013,143:267−275. doi: 10.1007/s10562-013-0963-0
    [28] JI Y J, YANG H H, YAN W. Catalytic cracking of n-hexane to light alkene over ZSM-5 zeolite: Influence of hierarchical porosity and acid property[J]. Mol Catal,2018,448:91−99. doi: 10.1016/j.mcat.2018.01.027
    [29] TRANCA D C, ZIMMERMAN P M, GOMES J, LAMBRECHT D, KEIL F J, HEAD G, M, BELL A T. Hexane Cracking on ZSM-5 and Faujasite Zeolites: a QM/MM/QCT Study[J]. J Phys Chem,2015,119(52):28836−28853.
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出版历程
  • 收稿日期:  2021-03-15
  • 修回日期:  2021-04-10
  • 网络出版日期:  2021-09-13

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