ZSM-5分子筛催化甲苯和三甲苯的歧化与烷基转移反应  

Disproportionation and Transalkylation of Toluene and Trimethylbenzene Catalyzed by ZSM-5 Zeolite

作　　者：张萌[1] 王先桥[1] 安亚雄[1] 李世雄[1] 舒小玲 金放[1] 吴元欣[1] 

机构地区：[1]武汉工程大学化工与制药学院绿色化工过程教育部重点实验室,湖北省新型反应器与绿色化学工艺重点实验室,湖北武汉430074

出　　处：《化学与生物工程》2016年第11期8-14,共7页Chemistry & Bioengineering

基　　金：国家自然科学基金资助项目(21306143);湖北省乙烯工程下游产品开发及过程强化协同创新中心开放基金资助项目;武汉工程大学大学生校长基金资助项目(2015013)

摘　　要：采用碱处理的方式改性ZSM-5分子筛,考察了温度、空速等反应条件和ZSM-5分子筛硅铝比对催化甲苯与1,2,4-三甲苯烷基化转移和歧化反应的反应物转化率和产物选择性的影响。结果表明,温度升高有利于提高反应物转化率及苯的选择性;提高空速,反应物转化率降低,苯的选择性降低,1,2,3-三甲苯的选择性升高。当硅铝比由120降至38时,反应物转化率明显提高,苯与二甲苯选择性也略有升高,而1,2,3-三甲苯选择性降低。碱处理改性降低了ZSM-5分子筛的硅铝比,在分子筛中引入了介孔结构;硅铝比的降低导致反应物转化率有明显升高;介孔结构的引入可以有效地提高催化剂的稳定性。ZSM-5 zeolite was modified with alkaline treatment and applied for toluene and 1,2,4-trimethylbenzene transalkylation and disproportionation reaction. The effects of silica-alumina ratio of ZSM-5 zeolite, temperature, space velocity and other reaction conditions on the reactant conversion and product selectivity were investigated. The results showed that, the temperature was in favor of increasing the reactant conversion and the selectivity of benzene. The increase of space velocity caused the decrease of reactant conversion and selectivity of benzene,while the selectivity of 1,2,3-trimethylbenzene increased. When the silica-alumina ratio decreased from 120 to 38,reactant conversion was improved significantly,the selectivity of benzene and xylene increased slight- ly,and at the same time the selectivity of 1,2,3-trimethylbenzene decreased. Alkaline treatment caused the in- crease of silica-alumina ratio of ZSM-5 zeolite and introduced the mesopore into the zeolite structure which caused a significant increase for the conversion of reactants, but had little effect on product selectivity, and the stability of the catalyst was improved after the alkaline treatment.

关 键 词：ZSM-5分子筛 碱处理 歧化反应 烷基转移 

分 类 号：TQ426.94[化学工程]