改性纳米ZSM-5催化剂上甲苯与碳酸二甲酯选择甲基化合成对二甲苯  

Shape-Selective Methylation of Toluene With Dimethyl Carbonate Into p-Xylene Over Modified Nano-Scale HZSM-5 Catalyst

作　　者：谭伟[1] 赵岩[1] 吴宏宇[1] 王祥生[1] 郭新闻[1] 

机构地区：[1]大连理工大学化工与环境生命学部,精细化工国家重点实验室,辽宁大连116024

出　　处：《石油学报（石油加工）》2011年第5期719-724,共6页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：教育部新世纪代表优秀人才支持计划(NCET-04-0268);高等学校学科创新引智计划(111计划)资助

摘　　要：以(6%SiO2+5%P2O5+3%MgO)/纳米ZSM-5为催化剂,在固定床反应器中,考察了甲苯(T)与碳酸二甲酯(DMC)甲基化合成对二甲苯(PX)的反应性能,特别是反应温度、水和甲苯与DMC摩尔比对反应性能的影响,并与甲醇(M)用作烷基化试剂的反应进行了对比。结果表明,DMC为烷基化试剂时,PX选择性达97%,反应40h后,催化剂很快失活。采用热重和紫外拉曼光谱对反应70h后的催化剂进行表征,发现用DMC作烷基化试剂时,催化剂积炭量较大,反应中引入水能在某种程度上减缓积炭的生成。Shape-selective methylation of toluene（T） with dimethyl carbonate（DMC） into p-xylene（PX） was carried out in a continuous flow fixed-bed reactor over（6%SiO2＋5%P2O5＋3%MgO）/nano-scale ZSM-5 catalyst.The influences of various reaction conditions,including reaction temperature,water and T/DMC molar ratio,on the reaction conversion and PX selectivity were investigated.The catalytic performances of catalyst in the methylation reaction with DMC and methanol as alkylation agent were compared.The results showed that DMC can be used as the alkylation agent in the methylation of toluene,and the PX selectivity reached 97%.However,the catalyst deactivated quickly after 40 h on stream.The spent catalysts were characterized by means of TG-DTA and UV-Raman,which indicated that the coking on the catalyst was serious,when dimethyl carbonate was used as alkylation agent,and it could be suppressed via the addition of water in the feed.

关 键 词：甲基化 纳米ZSM-5 甲苯 碳酸二甲酯 甲醇 对二甲苯 

分 类 号：TQ241.1[化学工程—有机化工]