Process for purifying dimethyl carbonate

A process for purifying dimethyl carbonate which comprises:

• (a) (1) continuously feeding a crude reaction mixture 1 which is a mixture mainly comprising dimethyl carbonate and methanol to a first column can A, and
• (2) simultaneously and continuously feeding a solution of dimethyl oxalate to the first column can A from the bottom of a second column can B wherein said dimethyl oxalate is added in an amount of 0.3 or more in terms of a mole fraction;
• (b) refluxing the mixture by heating the bottom of the first column to effect continuous distillation, removing methanol from the top of the first column as a first column distilled solution 3,
• (c) feeding a first column can solution 2 at the bottom thereof which is a mixture of dimethyl carbonate and dimethyl oxalate to the second column can B,
• (d) refluxing the mixture of dimethyl carbonate and dimethyl oxalate to effect continuous distillation, removing dimethyl carbonate from the top of the second column as a second column distilled solution 5, and
• (e) returning a second column can solution 4 at the bottom thereof which is dimethyl oxalate as a distillation residue to the first column can A.