Method for recovering trimethylbenzenes from mixtures which contain them.

摘要

A method is disclosed for recovering high-purity trimethylbenzenes from mixtures in which such compounds are contained together with ethyl-toluenes and possibly also butyl-benzenes, which method consists of treating such a mixture with benzene in the presence of a heterogeneous acidic catalyst selected from the group consisting of the so-said acidic earths and some types of porous crystalline catalysts in their protonic form, under conditions of transalkylation, and of subsequently separating the trimethylbenzenes by distillation. In fact, the transalkylation with benzene makes it possible ethyl-toluenes and in particular 2-ethyl-toluene to be preferentially or selectively converted into toluene and ethylbenzene, and any possibly present butyl-benzenes to be drastically reduced in amount, thus enabling an easy separation of trimethylbenzenes and in particular of pseudocumene and mesitylen to be accomplished by means of a simple distillation step.