摘要
采用等体积浸渍法制备了Pt/HBeta催化剂,并在10 mL固定床反应装置上评价了反应温度和质量空速对Pt/HBeta催化正己烷临氢异构化反应的影响,在此基础上建立正己烷异构化反应动力学模型。结果表明:在240~260℃内正己烷临氢异构化反应可以用拟一级动力学模型来描述,反应的活化能E_a=139.06 kJ/mol,指前因子A=7.3814×10~(13) h~(-1);建立了连串反应动力学模型,第一步反应活化能E_(a1)=167.80 kJ/mol,A_1=7.2130×10~(16) h~(-1),第二步反应活化能E_(a2)=118.34 kJ/mol,A_2=1.3053×10~(11) h~(-1);当反应温度大于260℃,拟一级动力学模型不再适合,修正后270℃时的反应级数为1.3,280℃时的反应级数为1.7。
The Pt/HBeta catalyst was prepared by the equivalent volume impregnation method and the hydroisomerization reaction of n-hexane was carried out in a 10 mL fixed-bed reactor. The effects of MHSV on the isomerization of n-hexane were investigated at different reaction temperatures. Based on these results, the kinetic model of the isomerization reaction was established. The results show that the hydroisomerization reaction of n-hexane at 240-260 ℃ can be described by a pseudo first-order kinetic model, in which the activation energy is E_a=139.06 kJ/mol, and the pre-factor is A=7.3814×10~(13) h~(-1). Further, we proposed a kinetic model for the sequential reaction, where at the first step, E_(a1)=118.34 kJ/mol, A_1=7.2130×10~(16) h~(-1), and at the second step, E_(a2)=118.34 kJ/mol, A_2=1.3053×10~(11) h~(-1). We found that pseudo first-order kinetic model is not applicable when temperature is higher than 260 ℃. After corrections, the reaction order at 270 ℃ is 1.3 and the reaction order at 280 ℃ is 1.7.
引文
[1] 任建生.轻质烷烃异构化工艺技术[J].炼油技术与工程,2013,43(7):28-31.(REN Jiansheng.Light paraffin isomerization technology[J].Petroleum Refinery Engineering,2013(7):28-31.)
[2] CHAO K J,WU H C,LEU L J.Hydroisomerization of light normal paraffins over series of platinum-loaded mordenite and beta catalysts[J].Applied Catalysis A:General,1996,143(2):223-243.
[3] MATSUDA T,KODAMA H,SAKAGAMI H,et al.Comparison of the catalytic properties of H2-reduced Pt/MoO3 and of Pt/zeolites for the conversions of pentane and heptane[J].Applied Catalysis A:General,2003,248(1/2):269-278.[3] 宋月芹,刘锋,康承琳,等.不同分子筛负载Pt催化剂上的正己烷异构化[J].石油学报(石油加工),2009,25(3):344-350.(SONG Yueqin,LIU Feng,KANG Chenglin,et al.Hexane isomerization over Pt catalysts supported on different zeolites[J].Acta Petrolei Sinica (Petroleum Processing Section),2009,25(3):344-350.)
[4] 冯延龙,宋月芹,张娟娟,等.Pt/Beta、Pt/SO42-/ZrO2和Pt/WO3/ZrO2催化剂上的正己烷异构化[J].石油学报(石油加工),2010,26(4):531-537.(FENG Yanlong,SONG Yueqin,ZHANG Juanjuan,et al.Hexane isomerization over Pt/Beta,Pt/SO42-/ZrO2 and Pt/WO3/ZrO2 catalysts[J].Acta Petrolei Sinica (Petroleum Processing Section),2010,26(4):531-537.)
[5] 柴章民,李承烈,黄国雄,等.丝光沸石催化剂上正己烷异构化反应机理[J].华东化工学院学报,1990,(6):599-606.(CHAI Zhangmin,LI Chenglie,HUANG Guoxiong,et al.Reaction mechanism of n-hexane isomerization over mordenite catalyst[J].Journal of East China Institute of Chemical Technology,1990,(6):599-606.)
[6] 刘雪暖,查宇慧,腾波涛.正己烷在Ni/HM催化剂上的异构化反应动力学模型[J].石油大学学报(自然科学版),2002,26(2):82-85.(LIU Xuenuan,ZHA Yuhui,TENG Botao.Kinetic model of isomerization of n-hexane over Ni/HM catalyst[J].Journal of the University of Petroleum,China (Edition of Natural Science),2002,26(2):82-85.)
[7] 朱泽霖,李承烈,黄国雄.己烷临氢异构化的复杂反应动力学网络[J].化学学报,1996,54(10):972-978.(ZHU Zelin,LI Chenglie,HUANG Guoxiong.Complex reaction kinetic network of hexane hydroisomerization[J].Acta Chimica Sinica,1996,54(10):972-978.)
[8] TOCH K,THYBAUT J W,MARIN G B.A systematic methodology for kinetic modeling of chemical reactions applied ton-hexane hydroisomerization[J].Aiche Journal,2015,61(3):880-892.
[9] 孙媛媛.Pt/HBeta正戊烷异构化催化剂的构效关系及动力学研究[D].上海:华东理工大学,2017.
[10] 刘铁生,何奕工.C5、C6正构烷烃异构化反应的热力学分析[J].石油学报(石油加工),2003,19(3):94-98.(LIU Tiesheng,HE Yigong.Thermodynamic analysis of isomerization of n-C5 and n-C6[J].Acta Petrolei Sinica (Petroleum Processing Section),2003,19(3):94-98.)
[11] CHEKANTSEV N V,GYNGAZOVA M S,IVANCHINA E D.Mathematical modeling of light naphtha (C5,C6) isomerization process[J].Chemical Engineering Journal,2014,238(4):120-128.
[12] VOLKOVA G G,RESHETNIKOV S I,SHKURATOVA L N,et al.n-Hexane skeletal isomerization over sulfated zirconia catalysts with different Lewis acidity[J].Chemical Engineering Journal,2007,134(1):106-110.
[13] 马伟,张持,李倩,等.反应活化能与反应级数的测定[J].化工高等教育,2015,32(4):63-66.(MA Wei,ZHANG Chi,LI Qian,et al.Determination of reaction activation energy and reaction order[J].Higher Education in Chemical Engineering,2015,32(4):63-66.)Kinetics Model of the Hexane Isomerization on a Pt/HBeta CatalystZHANG Kongyuan XIAO Changlin LIU ChenguangThe effects of MHSV on the isomerization of n-hexane were investigated under different reaction temperatures.Subsequently,the kinetic model of isomerization reaction was established.