Method and system for separating butyl acetate and n-butanol coupled with pressure swing and heat pump rectification

Abstract

The invention discloses a method and a system for separating butyl acetate and n-butanol through coupling of pressure-swing distillation and heat-pump distillation. Aiming at the current situation that azeotrope of butyl acetate and n-butanol is difficult to separate, a series connection process of two towers with different tower pressures is adopted, the pressure-swing distillation method principle is utilized for separation, a whole process system is subjected to heat energy integrated utilization, so that the cooling quantity of steam at the top of a second distillation tower is reduced, the heating quantity of raw material stream of a first distillation tower is reduced, meanwhile, the steam consumption of a column reactor of the first distillation tower is reduced, operation conditions of the two distillation tower are independent, the control is convenient, and the purity of butyl acetate and the purity of n-butanol can be effectively improved. The problems that the conventional azeotrope is difficult to separate, a third component is required to be introduced, the energy consumption is high and the like are effectively solved, the purity of butyl acetate and the purity of n-butanol can be up to or higher than 98.5%, the yield of is butyl acetate and the yield of n-butanol are close to 100%, the process energy consumption is reduced by about 45%, an energy-saving, environment-friendly and high-efficient separation technology is provided, and the market application prospect is broad.

Description

technical field [0001] The invention belongs to the technical field of chemical industry and relates to a separation method applied to the azeotropic system of butyl acetate and n-butanol. Background technique [0002] Butyl acetate is an important organic chemical raw material, widely used in medicine, spices, plastics, varnish, nitrocellulose, artificial leather, etc. It can be used as an organic solvent to dissolve polyvinyl acetate, polyacrylate, polyvinyl chloride, chlorinated Rubber, polymethyl methacrylate, etc. The production of butyl acetate is mainly obtained by the esterification reaction of n-butanol and glacial acetic acid catalyzed by concentrated sulfuric acid and the transesterification reaction of methyl acetate and n-butanol. All there is butyl acetate-n-butanol azeotrope (the azeotropic temperature under normal pressure is 116.2 ℃ in the reaction system of these two kinds of preparation butyl acetates, and butyl acetate accounts for 36.7% (wt) in the azeo...

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Problems solved by technology

[0005] The technical purpose of the present invention is to provide a method for coupling separation of butyl acetate and n-butanol with variable pressure and heat pump rectification for the problems of difficult separation and high energy consumption of butyl acetate and n-butanol azeotropic system in the prior art. method and system

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