Separation of methanol-acetonitrile by batch extractive distillation with aniline as solvent

In this paper,aniline was proposed as the solvent for the separation of the azeotrope methanol-acetonitrile by batch extractive distillation and the process was studied.Aniline was selected as the suitable solvent on the basis of the law of similarity and dissolvability,combined with VLE simulation by ChemCAD software and the VLE experiments.The results show that aniline as the solvent could break the azeotrope and the effects of aniline were better than N,N-dimethylformamide(DMF).The Wilson model was used in VLE simulation.The experiment on the separation of the azeotrope methanol and acetonitrile by batch extractive distillation was carried out with a packed column with 33 theoretical plates among which 3 theoretical plates are in rectifying and recovery section and 30 theoretical plates in extractive distillation section.With the reflux ratio of 4,and the solvent mass ratio of 2.5∶1,the product purity of methanol reaches 98.97%,which is higher than the value of 95.76% when DMF was used as the solvent.It indicates that the extractive distillation with aniline as solvent is more suitable for the separation of azeotrope methanol-acetonitrile.