留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名
邮箱
手机号码
标题
留言内容
验证码

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研究[J]. 燃料化学学报(中英文), 2021, 49(10): 1522-1530. 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研究[J]. 燃料化学学报(中英文), 2021, 49(10): 1522-1530. 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, 2021, 49(10): 1522-1530. 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, 2021, 49(10): 1522-1530. 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研究

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 (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产物的总选择性明显高于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。
  • FIG. 971.  FIG. 971.

    FIG. 971. 

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

    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−1)Sexter/(m2·g−1)vtotal/(cm3·g−1)vmicro/(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-FTIR
    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: Gen,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: Gen,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,2015,135:452−460.
    [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,2019,138:270−280.
    [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] ARMAROLI T, TROMBETTA M, GUTIÈRREZ ALEJANDRE A, RAMIREZ SOLIS J, BUSCA G. FTIR study of the interaction of some branched aliphatic molecules with the external and internal sites of H-ZSM5 zeolite[J]. Phys Chem Chem Phys,2000,2(14):3341−3348. 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.
  • 加载中
图(8) / 表(2)
计量
  • 文章访问数:  236
  • HTML全文浏览量:  36
  • PDF下载量:  14
  • 被引次数: 0
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
  • 刊出日期:  2021-10-30

目录

    /

    返回文章
    返回