Method of purifying propylene epoxide

Abstract

The invention provides a method of purifying propylene epoxide. The method comprises a step of feeding a solution containing the propylene epoxide, an organic solvent and water into a propylene epoxide purification and separation unit, and separating to obtain a propylene epoxide product and an organic solvent-water solution; and a step of feeding the organic solvent-water solution into a multiple-effect evaporation system containing a plurality of tower separators to recover the organic solvent, wherein the boiling point of the organic solvent is lower than the boiling point of the water, and by controlling conditions of the highest-pressure evaporation stage in the multiple-effect evaporation system, organic solvent vapor obtained from the tower top of the lowest-pressure evaporation stage in the multiple-effect evaporation system can be used as at least one part of the heat resource of the propylene epoxide purification and separation unit. The energy consumption and the equipment cost of the method are low.

Description

technical field [0001] The invention relates to a method for refining propylene oxide. Background technique [0002] Propylene oxide (Propylene Oxide) is an important raw material for organic synthesis. It is the third largest propylene derivative except polypropylene and acrylonitrile. It is mainly used in the production of polyether, propylene glycol, propylene glycol ether, etc., and is also a nonionic surfactant. , oil field demulsifier, pesticide emulsifier and other important raw materials. Propylene oxide derivatives are also widely used in food, tobacco, pesticide and cosmetic industries. At present, nearly a hundred kinds of downstream products have been produced, and they are important raw materials for fine chemical products. [0003] At present, the production processes of propylene oxide mainly include the chlorohydrin method, the co-oxidation method and the direct oxidation method. Among them, the first two production methods have defects such as high cost and...

AI Technical Summary

Problems solved by technology

[0009] The process of multi-effect distillation can be divided into two-effect, three-effect, etc. according to the number of effects. However, as the number of effects increases, although the energy consumption decreases, the number of columns also increases, resulting in a substantial increase in equipment investment costs.

Moreover, the more the number of effects, the lower and lower the energy-saving effect of each additional effect. Therefore, in the actual application process, too many effects cannot be used. At present, the most commonly used in industrial production multi-effect distillation is two Effect, three effect, and more than four effect distillation processes are rare

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