THE SEPARATION OF METHYL ACETATE FROM METHANOL BY EXTRACTIVE DISTILLATION

Methyl acetate cannot be completely removed from methyl acetate-methanol mixtures by distillation because of the presence of the minimum binary azeotrope. Methyl acetate can be readily removed as overhead product from mixtures containing it and methanol by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are dimethylsulfoxide, glycerine plus propylene glycol, ethylene glycol plus dimethylsulfoxide plus 1,5-pentanediol. Methanol can be removed as the overhead product from methyl acetate when the extractive distillation agent is nitrobenzene, propylene carbonate or ethylene glycol phenyl ether.