偏三甲苯生产均三甲苯工艺

在偏三甲苯异构化生产均三甲苯的过程中 ,虽然反应液中均三甲苯含量较高 ,但甲乙苯的累积使该过程的工业化难度大 ,生产成本高 .采用独特的异构化和烷基化反应联合工艺 ,通过烷基化有效抑制甲乙苯的累积 ,其副产品四甲苯用作异构化的原料以抑制歧化副反应 ,而异构化可弥补烷基化中均三甲苯含量低的缺陷 ,从而有效地实现均三甲苯的工业化 ,生产成本大幅度降低 .研究了工艺条件对反应的影响 ,找到了最佳的工艺条件 .目前 ,此工艺已实现了年产 6 0 0t纯度为 98.5 %的均三甲苯的工业化生产

TECHNOLOGY OF PRODUCTION OF 1,3,5-TRIMETHYLBENZENE FROM 1,2,4-TRIMETHYLBENZENE

Although the content of 1,3,5-trimethylbenzene is high in the isomerization of 1,2,4-trimethylbenzene, the process is extremely difficult to be realized industrially because of the accumulation of methylethylbenzene. A unique process using isomerization and alkylation as a union has been studied, in which alkylation is used to relieve the accumulation of metylethhylbenzene whose by-product can be used as parts of raw materials in isomerization to control the side reactions, and isomerization can raise the content of 1,3,5-trimethylbenzene. Thus 1,3,5-trimethylbenzene and the coproduct 1,2,4,5-tetramethylbezene can be produced industrially. Moreover, the production cost can be lowered greatly. Meanwhile, the effects of technological conditions on the reactions have been discussed, and the optimum technological conditions offered. The technology has now been used industrially to produce 600t/a 98.5% 1,3,5-trimethylbenzene.