四乙基氢氧化铵后晶化处理对ZSM-5分子筛结构及其甲醇制丙烯催化性能的影响  

Enhancing the Catalytic Performance of ZSM-5 Zeolite in Methanol to Propene Reaction via Recrystallization in the Presence of Tetraethylammonium Hydroxide

作　　者：张云鹏[1] 李明罡[1] 王萍[1] 邢恩会[1] 罗一斌[1] 舒兴田[1] ZHANG Yunpeng;LI Minggang;WANG Ping;XING Enhui;LUO Yibin;SHU Xingtian(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：《石油学报（石油加工）》2018年第4期817-824,共8页Acta Petrolei Sinica(Petroleum Processing Section)

摘　　要：采用四乙基氢氧化铵(TEAOH)溶液对以四丙基氢氧化铵(TPAOH)为模板剂合成的高硅ZSM-5分子筛进行"后晶化"处理,制得晶内扩孔的多级孔ZSM-5分子筛。采用X-射线衍射仪(XRD)、N_2物理吸附、透射电子显微镜(TEM)、氨气程序升温脱附仪(NH_3-TPD)等对母体及改性后的ZSM-5分子筛进行物化性能表征,并采用固定床微反应装置考察其在甲醇制丙烯(MTP)反应中的催化性能。结果表明,TEAOH后晶化处理使高硅ZSM-5分子筛形成晶内介孔,在相对结晶度保留较高的同时,介孔孔容增加超过50%,成为具有微、介孔结构的多级孔分子筛。在反应温度480℃、反应压力0.1 MPa、甲醇/水质量比1/1、甲醇质量空速4.5h-1的条件下,多级孔ZSM-5分子筛的丙烯碳基收率比母体ZSM-5分子筛略有提高,寿命由改性前的25h增加至100h。Highly siliceous ZSM-5 zeolite synthesized with tetrapropylammonium hydroxide（TPAOH）as structure-directing agent was post-treated by tetraethylammonium hydroxide（TEAOH）,to obtain intracrystalline mesopores.Both ZSM-5 and hierarchical ZSM-5 zeolites were characterized by X-ray diffraction（XRD）,N2-adsorption,transmission electron microscope（TEM）and NH3 temperature-programmed desorption（NH3-TPD）.Methanol to propylene reaction over ZSM-5 and hierarchical ZSM-5 zeolites was carried out in a fixed-bed microreactor.It is shown that TEAOH treatment of high siliceous ZSM-5 generates the intracrystalline mesopore by more than50% with high relative crystallinity because of the participation of tetraethylammonium ion（TEA＋）.Under the following operating conditions：T=480℃,p=0.1 MPa,m（Methanol）/m（H2O）=1/1 and methanol mass hourly space velocity MHSV=4.5 h-1,the yield of propylene for hierarchical ZSM-5 zeolite is much higher than that of ZSM-5.Moreover,it exhibits long catalytic lifespan from25 hours to 100 hours.

关 键 词：ZSM-5 四乙基氢氧化铵(TEAOH) 后晶化处理 甲醇制丙烯(MTP) 

分 类 号：TQ426.94[化学工程]