Method for preparing carbonic acid glyceride by catalytic reaction-azeotropic reification coupling

Abstract

The invention discloses a method for preparing carbonic acid glyceride by catalytic reaction-azeotropic reification coupling, and belongs to the technical field of fine chemistry. In the method, the catalytic reaction and the azeotropic rectification are finished in the same rectification tower; glycerol, dimethyl carbonate, a solid base catalyst and an azeotropic agent are added into a tower; the tower is heated while the raw materials are stirred; the tower operation temperature is between 60 and 120 DEG C; the tower top operation temperature is between 50 and 80 DEG C; a mixture of methanol and the azeotropic agent is taken out of the top of the tower in a reflux ratio of 2 to 6; the reaction time is 0.1 to 3 hours; the operational pressure of the top of the rectification tower is the normal pressure; the mol ratio of the dimethyl carbonate to the glycerol is 1-1.5:1; the reaction products in the tower are subjected to vacuum evaporation to remove the azeotropic agent and filtered to remove the catalyst; and finally the carbonic acid glyceride is obtained. The solid base catalyst in the method has the advantages of low in price, convenient recovery, and cyclically used. Due to the lower mol ratio of the methyl carbonate to the glycerol, the consumption of the methyl carbonate is lowered. The process for purifying the carbonic acid glycerol products is simple.

Description

technical field [0001] The invention relates to a method for preparing glycerol carbonate by glycerin and dimethyl carbonate, in particular to a method for preparing glycerol carbonate by coupling catalytic reaction-azeotropic distillation. Background technique [0002] Glycerol carbonate is a new type of important chemical product, which is a cyclic carbonate. Glycerol carbonate has a wide range of uses and a large market demand. It can be used as a solvent in the production of emulsifiers, paint removers, paints and cosmetics. Glycerol carbonate and its derivatives can also be used in the electrolyte of fuel cells, and can also be used as liquid membranes for the separation of carbon dioxide and nitrogen. Due to its active nature, glycerol carbonate can be used as an intermediate in the production of chemical products, for example, it can be used to produce glycidyl ether, and it can also be used to produce glycosides, cross-linked polymers, pharmaceutical intermediates, ...

AI Technical Summary

Problems solved by technology

The disadvantages of these methods of using carbon monoxide to synthesize glycerol carbonate are that carbon monoxide is poisonous, and the reaction time is long, the reaction temperature is high, the reaction pressure is high, and the requirements for equipment are high.

However, there are many shortcomings in the current production method: 1. In terms of catalyst selection, the activity of immobilized enzymes is low and the price is expensive

The deactivation problem that calcium oxide catalyst exists; Two, the consumption of dimethyl carbonate is too large, in order to improve the yield of glycerol carbonate, adopted the very high mol ratio of dimethyl carbonate and glycerol

3. The deactivation of the catalyst and the too high molar ratio of dimethyl carbonate to glycerol have caused a burden on the subsequent treatment and made the subsequent treatment process complicated