Pervaporation-normal pressure rectification integrated process for separating dimethyl carbonate and methanol

Abstract

The invention provides a pervaporation-normal pressure rectification integrated process for separating dimethyl carbonate and methanol. The process is characterized in that when the azeotropic solution of dimethyl carbonate and methanol obtained in a reactive rectification tower passes through a pervaporation membrane system and due to the difference of the adsorption permselectivity of a pervaporation membrane to components, the methanol-dimethyl carbonate azeotropic bottleneck is effectively broken, the low-concentration side dimethyl carbonate liquid is returned to the reactive rectification tower for cyclic separation, while the high-concentration side dimethyl carbonate liquid is conveyed to a normal pressure rectification tower and separated by the normal pressure rectification tower to obtain the dimethyl carbonate product having the quality purity of more than 99.6% at the bottom of the tower, and the methanol-dimethyl carbonate azeotropic liquid obtained at the top of the tower is mixed with the azeotropic liquid of the reactive rectification tower for next cyclic separation. According to the pervaporation-normal pressure rectification integrated process for separating dimethyl carbonate and methanol, the quality of the dimethyl carbonate product is improved at low energy consumption and the production process and equipment are simplified; the process has the advantages of simplicity and convenience in operation, economic efficiency, adjustability, high integrity and the like.

Description

technical field [0001] The invention relates to a process for the integrated separation of dimethyl carbonate and methanol by pervaporation-atmospheric rectification, and belongs to the technical field of dimethyl carbonate separation. Background technique [0002] Dimethyl Carbonate (Dimethyl Carbonate, referred to as DMC) is a green chemical product that meets the requirements of modern "clean technology" and is environmentally friendly. It is also an important organic synthesis intermediate and starting material. Phenols, alcohols, amines, hydrazines, and esters react to synthesize many compounds with special properties; secondly, DMC has excellent solubility properties, and can be used as a low-toxicity solvent and cleaning agent in the fields of medicine, coatings, batteries, etc.; in addition, DMC The oxygen content reaches 53.3%. As a gasoline additive, it can increase the octane number of gasoline, improve combustion efficiency, and reduce exhaust pollution. [0003...

AI Technical Summary

Problems solved by technology

However, the pervaporation-distillation integrated process still needs to be improved in the production process of dimethyl carbonate. For example, most of the high-concentration by-product methanol will still be added to the reactive distillation column as a reactant. On the premise of maintaining the quality of dimethyl ester products, further simplify the production process, thereby reducing more energy consumption and reducing operating costs, and there is still innovation work to be done

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