不同结构扩孔分子筛催化MTP反应行为及表面积炭物种表征  

Methanol to propylene reaction performance and trapped carbonaceous species over zeolites with different topologies

作　　者：张云鹏[1] 李明罡[1] 邢恩会[1] 罗一斌[1] 舒兴田[1] ZHANG Yun-peng;LI Ming-gang;XING En-hui;LUO Yi-bin;SHU Xing-tian(Research Institute of Petroleum Processing,SINOPEC,Beijing 100083,China)

机构地区：[1]中国石化石油化工科学研究院,北京100083

出　　处：《燃料化学学报》2018年第9期1101-1112,共12页Journal of Fuel Chemistry and Technology

摘　　要：采用TEAOH溶液处理MFI结构ZSM-5分子筛、MWW结构MCM-22分子筛,NaOH溶液处理TON结构ZSM-22分子筛、CHA结构SSZ-13分子筛得到四种结构的扩孔分子筛。在反应温度480℃、反应压力0.1 MPa、甲醇与水质量比1∶1、甲醇质量空速1.5 h^(-1)的条件下,考察了四种扩孔分子筛的甲醇制丙烯(MTP)催化性能,并采用XRD、N_2吸附-脱附、NH_3-TPD、TG、UV-Raman和GC-M S等方法表征催化剂的物化性质及M TP反应2 h后的分子筛积炭性质。结果表明,四种分子筛扩孔改性后均出现介孔,其中,T-ZSM-5分子筛在MTP反应中寿命最长;T-MCM-22分子筛寿命次之且失活速率慢;而一维孔道结构N-ZSM-22分子筛和八元环尺寸较小的N-SSZ-13分子筛均失活迅速。受拓扑结构和孔道扩散的影响,MTP反应2 h后,分子筛积炭量增加的顺序为T-ZSM-5<N-ZSM-22<T-MCM-22<N-SSZ-13且可溶焦分子质量随积炭量增加而增重,即从五甲基苯增重到菲、芘等多环芳烃。Mesoporous ZSM-5(MFI),MCM-22(MWW),ZSM-22(TON)and SSZ-13(CHA)zeolites were obtained by TEAOH and NaOH solution treatment.Under the following operating conditions:t=480℃,p=0.1 MPa,m(methanol):m(H 2O)=1∶1 and WHSV(methanol)=1.5 h-1,the catalytic properties of four mesoporous zeolites with different topologies were investigated in the methanol to propylene(MTP)reaction.The fresh and spent samples after 2 h were characterized with XRD,nitrogen adsorption experiments,NH 3-TPD,TG,UV-Rama and GC-MS techniques.It demonstrated that both zeolites exist mesopores after treated by alkali.The mesoporous T-ZSM-5 zeolite had the highest lifetime;the lifetime of T-MCM-22 zeolite with was secondary and deactivation rate was slow;The N-ZSM-22 with one-dimensional channel structure and N-SSZ-13 zeolite with 8-member ring channels both deactivated rapidly.Due to the difference of topology structure and diffusion performance,their coke contents after 2 h increased in the order:T-ZSM-5<N-ZSM-22<T-MCM-22<N-SSZ-13.Moreover,the molecular weight of soluble coke increased with the increasing of coke contents,changed from pentamethylbenzene to polycyclic aromatic hydrocarbons,such as phenanthrene and pyrene.

关 键 词：甲醇制丙烯 介孔 分子筛拓扑结构 积炭行为 

分 类 号：TQ426.94[化学工程]