Method for separating methylbenzene, dimethylbenzene and trimethylbenzene in aromatic solvent oil

The invention discloses a method for separating methylbenzene, dimethylbenzene and trimethylbenzene in aromatic solvent oil. The method includes: separating methylbenzene, dimethylbenzene and trimethylbenzene in aromatic solvent oil by the connection of side stripping, extractive distillation and solvent recycling. The method has a simple process and is easy to implement, and all extracting agents used in the separation process are recyclable. The methylbenzene separated by means of the method of the invention has a purity >/=99.0wt% and yield higher than 99.85%; the dimethylbenzene separated by means of the method has a purity >/=99.5wt% and yield higher than 99.34%; the trimethylbenzene separated by means of the method has a purity >/=90.4wt% and yield up to higher than 62.28%. 本发明公开了种芳烃溶剂油中甲苯、二甲苯以及三甲苯的分离方法，所述方法采用侧线精馏、萃取精馏以及溶剂回收相结合分离芳烃溶剂油中甲苯、二甲苯以及三甲苯，所述方法工艺简单、易于实现，且分离过程中所使用的萃取剂均可回收使用。本发明所述方法分离得到的甲苯纯度≥99.0wt％、产率可达到99.85％以上；二甲苯纯度≥99.5wt％、产率可达到99.34％以上；三甲苯纯度≥90.4wt％、产率可达到62.28％以上。