多级孔花状ZSM-5分子筛的合成及其正辛烷催化裂解反应性能研究  

Study on synthesis of hierarchical flower⁃like ZSM-5 zeolite and its catalytic performance for n-octane cracking

作　　者：王健捷 束小龙 肖霞 王鹏[2] 范晓强 孔莲 解则安 赵震 WANG Jianjie;SHU Xiaolong;XIAO Xia;WANG Peng;FAN Xiaoqiang;KONG Lian;XIE Zean;ZHAO Zhen(College of Chemistry and Chemical Engineering,Institute of Catalysis for Energy and Environment,Shenyang Normal University,Shenyang 110034,China;State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Beijing 102249,China)

机构地区：[1]沈阳师范大学化学化工学院,能源与环境催化研究所,辽宁沈阳110034 [2]中国石油大学(北京),重质油国家重点实验室,北京102249

出　　处：《无机盐工业》2024年第8期139-146,共8页Inorganic Chemicals Industry

基　　金：辽宁省教育厅基本科研项目(LJKMZ20221476);沈阳市中青年科技创新人才支持计划项目(RC220357);辽宁省研究生教育教学改革研究项目(LNYJG2022400);沈阳师范大学化学化工学院教育教学改革研究项目(CCCE2020JG03)。

摘　　要：高性能催化剂的研发是石脑油催化裂解制低碳烯烃领域的研究热点。使用双子季胺盐表面活性剂[C_(18)H_(37)-N^(+)(CH_(3))_(2)-C_6H_(12)-N^(+)(CH_(3))_(2)-C_6H_(13)]Br_(2)作为结构导向剂,成功合成了花状ZSM-5分子筛。利用XRD、SEM、N_(2)吸附-脱附和NH_(3)-TPD表征技术研究了晶化温度、n(Si)/n(Al)、n(H_(2)O)/n(Si O_(2))和n(Na_(2)O)/n(Si O_(2))等合成条件对ZSM-5分子筛物化性质的影响,并考察其正辛烷催化裂解反应性能。研究结果表明,花状ZSM-5分子筛的优化制备条件为:n(Na_(2)O)∶n(Al_(2)O_(3))∶n(Si O_(2))∶n(C_(18-6-6)Br_(2))∶n(H_(2)O)=5∶1∶100∶10∶4000、晶化时间为72 h、晶化温度为175℃。随着n(Si)/n(Al)的增大,花状分子筛颗粒逐渐团聚;当投料n(Na_(2)O)/n(Si O_(2))高于0.05时,分子筛样品中开始出现其他杂相;随着投料n(H_(2)O)/n(Si O_(2))的增大,分子筛层状形貌逐渐不明显。在催化裂解正辛烷制乙烯和丙烯反应中,经过30 h连续测试,花状ZSM-5分子筛的正辛烷转化率始终保持稳定,乙烯和丙烯总收率从62.0%逐渐增加至64.4%。花状ZSM-5分子筛较高的催化活性和优异的抗积炭稳定性主要归结于其独特的层状形貌和多级孔结构。The research and development of high activity catalysts has been a hot topic in the field of catalytic cracking of naphtha to produce light olefins.In this paper,the flower‐like ZSM-5 zeolite was synthesized by using the Gemini quater‐nary ammonium surfactant[C_(18)H_(37)-N^(+)(CH_(3))_(2)-C_(6)H_(12)-N^(+)(CH_(3))_(2)-C_(6)H_(13)]Br_(2) as structure‐directing agent.The effects of crys‐tallization temperature,n(Si)/n(Al),n(H_(2)O)/n(SiO_(2))and n(Na_(2)O)/n(SiO_(2))on the physicochemical properties of the ZSM-5 zeolite were investigated by XRD,SEM,N_(2) adsorption‐desorption and NH_(3)-TPD characterization techniques,and the catalytic cracking performance of n-octane on ZSM-5 zeolite was investigated.The research results showed that forma‐tion of flower ZSM-5 zeolite was optimized preparation conditions is the raw material molar composition of n(Na_(2)O)∶n(Al_(2)O_(3))∶n(SiO_(2))∶n(C_(18-6-6)Br_(2))∶n(H_(2)O)=5∶1∶100∶10∶4000,crystallization time of 72 h,the crystallization temperature of 175℃.With the increase of n(Si)/n(Al),the flower‐like ZSM-5 particles tended to agglomerate more.When the feeding n(Na_(2)O)/n(SiO_(2))was higher than 0.05,other heterophase appeared in the zeolite samples.With the increase of n(H_(2)O)/n(SiO_(2)),the layer morphology of ZSM-5 zeolite gradually became less obvious.In the catalytic cracking of n-octane to eth‐ylene and propylene,the conversion of n-octane on the flower‐like ZSM-5 zeolite remained stable after 30 h continuous testing,and the total yield of ethylene and propylene was gradually increased from the initial 62.0%to 64.4%.The high cata‐lytic activity and excellent anti‐carbon stability of the flower‐like ZSM-5 zeolite were mainly attributed to its unique layered morphology and hierarchical structure.

关 键 词：低碳烯烃 多级孔 ZSM-5分子筛 催化裂解 晶化条件 

分 类 号：TQ426[化学工程]