催化裂化干气中稀乙烯与甲苯烷基化制对甲基乙苯的研究

ALKYLATION OF TOLUENE WITH DILUTE ETHYLENE IN FCC DRY GAS FOR PRODUCING P ETHYLTOLUENE

为合理利用甲苯和催化裂化干气中的乙烯，在小型试验装置上研究，直接用催化裂化干气作原料与甲苯用Ｌａ／ＺＳＭ－５择形沸石催化剂烷基化，制对甲基乙苯。试验结果表明，在３５０～４００℃、压力０．４～０．７ＭＰａ、甲苯／乙烯的摩尔比为４～７、空速为０．３～０．７ｈ－１的条件下反应，乙烯转化率可达５０％～８４．５％，生成的甲基乙苯中对位的选择性为９０％左右，反应所得烷基化液用通常的分离技术可获纯度为９９．７１％的对甲基乙苯，循环甲苯的纯度可达９８．３％。催化剂的初活性高，单程操作周期在１５ｄ以上。

Alkylation of toluene and dilute ethylene in FCC dry gas for producing p ethyltoluene was conducted on a laboratory unit with La/ZSM 5 selective zeolite catalyst. The test results showed that under the conditions of a reaction temperature of 350～400 ℃, a pressure of 0.4￣0.7 MPa, a toluene/ethylene mol ratio of 4￣7 and a WHSV of 0.3￣0.7 h -1 , the ethylene convertion reached 50%￣84.5%; the selectivity of forming p ethyltoluene was about 90% and its purity was 99.71% after conventional separation from the alkylate; and the purity of the recycle toluene can reach 98.3%. The initial activity of the catalyst was high and the once through cycle was more than 15 days.