Mixed solvent for separating methyl acetate-methanol by extractive distillation

A number of solvents for separating the azeotropic system of methyl acetate-methanol were examined in a vapor-liquid equilibrium(VLE) experiment apparatus for solvent selection.The results show that with the increase of solvent mass ratio of the solvents,the relative volatility of the separation is increased,and binary mixed solvents of dimethyl sulfoxide(DMSO) and N,N-dimethyl formamide(DMF) and ternary mixed solvents of N-methyl pyrrolidinone(NMP),DMF and DMSO are superior to single solvent such as DMF.When the molar ratio of DMF to DMSO is 1,the separation performance is the best among all investigated solvents.The theoretical analysis was described roughly for intermolecular forces between the solvents and the solution molecules.The formation of the hydrogen bond enables facile between methanol as proton supplier and solvents as electron supplier,which can alter the activity coefficient of methanol in order to increase the volatility of methyl acetate relative to methanol.