PX生产工艺及研究进展

Production technology of para-xylene and research progress

介绍了工业上芳烃联合装置生产对二甲苯的甲苯歧化工艺、C9A芳烃烷基转移工艺、二甲苯异构化工艺、近几年工业化的甲苯甲醇烷基化工艺,相比甲苯歧化工艺,甲苯甲醇烷基化工艺具有甲苯转化率高、不会副产苯的优点,不会像甲苯歧化工艺存在甲苯异构化及多次分离的工艺过程。利用其他原料生产PX的新工艺包括合成气一步制PX工艺、苯和合成气制PX工艺、甲苯和合成气制PX工艺、烷烃转化制PX工艺,其中,合成气制二甲苯前景广阔,可在很大程度上减少PX生产的化学反应步骤,符合化学反应原子经济学原则,给合成气找到一条制取高附加值化学品的工艺途径。

This paper introduces the industrial processes for producing para-xylene(PX)in aromatic complex,including toluene disproportionation process,C9 A aromatics trans-alkylation process,xylene isomerization process,and the toluene-methanol alkylation process that is industrialized in recent years.Compared with toluene disproportionation process,the toluene-methanol alkylation process can gain a higher toluene conversion rate,does not produce benzene byproduct,avoids isomerization of toluene and does not need multi separation.Novel PX production processes by using other raw materials include one-step conversion of syngas to PX,benzene-syngas to PX,toluene-syngas to PX and alkane to PX.Of which,the one-step conversion of syngas to PX process has a bright future,which can reduce the chemical reaction steps greatly,in line with the chemical principle of reaction atomic economics,which is a route of producing high-value chemicals.