The invention discloses a method for continuous extraction
distillation separation of a
dimethyl carbonate-
methanol azeotropic mixture, and belongs to separation technologies of the
dimethyl carbonate-
methanol azeotropic mixture. According to the method, N,N-
dimethylformamide, N-formylmorpholine or a mixture consisting of N,N-
dimethylformamide and N-formylmorpholine in any proportion is used as an extracting agent. The operation condition of an extraction
distillation tower and a
solvent recovery tower are that the pressure is a normal pressure or reduced pressure, the ratio of a distillate at the top of the extraction
distillation tower to the extracting agent is (0.5:1)-(10:1), and the feed (
mass) ratio of the extracting agent to a mixture is (1:10)-(5:1). Two distillation towers are used in the method to achieve cycle utilization of the extracting agent.
Methanol meeting requirements is obtained at the top of the extraction distillation tower, and the distillate at the bottom of the tower enters the
solvent recovery tower; high-purity
methyl carbonate is obtained at the top of the
solvent recovery tower, and a high-purity extracting agent is obtained at the bottom of the tower; and a pump is used for pumping the extracting agent into the extraction distillation tower for cycle utilization. The method has the advantages that the extracting agent is adopted to destroy a
dimethyl carbonate-
methanol azeotropic
system, and the aims of separating high-purity dimethyl
carbonate and methanol and ensuring cycle utilization of the extracting agent are achieved. The
continuous distillation has the advantages of high tower efficiency, high yield and the like.