甲苯与碳酸二甲酯择形烷基化合成对二甲苯  

Selective synthesis of p-xylene by alkylation of toluene with dimethyl carbonate

作　　者：李永昕[1] 邓丽君[1] 薛冰[1] 

机构地区：[1]江苏工业学院化学化工学院,江苏常州213164

出　　处：《化工进展》2010年第4期665-669,共5页Chemical Industry and Engineering Progress

基　　金：江苏省高技术研究(BG2006015);江苏省高校重大基础研究(06KJA5013)资助项目

摘　　要：在气相连续流动固定床反应器上,以改性的MCM-22为催化剂,对甲苯与碳酸二甲酯(DMC)的择形烷基化合成对二甲苯(PX)进行了研究。以乙酸镁为前体,采用等体积浸渍法制备了一系列MgO改性的MCM-22催化剂,并通过X射线衍射、低温N2吸附-脱附和吡啶红外光谱等手段对催化剂进行了表征。考察了MgO负载量、反应温度、甲苯与DMC摩尔配比及重时空速对甲苯与DMC烷基化反应的影响。结果显示,采用乙酸镁为前体盐,催化剂能在保持较高甲苯转化率的同时显著提高对二甲苯选择性。采用12%MgO/MCM-22为催化剂,在反应温度653K、n(甲苯):n(DMC)=4:1,重时空速(WHSV)为1h-1条件下,甲苯转化率为31.01%,对二甲苯选择性达55.61%。Selective synthesis of p-xylene by alkylation of toluene with dimethyl carbonate（DMC） was carried out in a continuous flow fixed-bed reactor over MgO-modified MCM-22 molecular sieves.The MgO/MCM-22 catalysts were characterized by means of XRD,N2 adsorption-desorption and pyridine-IR.Effects of MgO loading and reaction conditions were investigated.Results indicated that a high toluene conversion can be achieved along with an obvious increase in the selectivity for p-xylene over MgO modified MCM-22 using Mg（AC）2 as precursor.The influence of various reaction conditions was studied over a 12% MgO/MCM-22 catalyst.Under the optimal conditions,i.e.reaction temperature of 653 K,n（toluene）：n（DMC） of 4 and WHSV of 1 h-1,the conversion of toluene and the selectivity to p-xylene were 31.01% and 55.61%,respectively.

关 键 词：MCM-22 氧化镁 碳酸二甲酯 甲苯 烷基化 对二甲苯 

分 类 号：TQ032.4[化学工程]