Clean production process for preparing normal propyl alcohol by propionaldehyde hydrogenation

Abstract

The invention relates to a clean production process for preparing normal propyl alcohol by propionaldehyde hydrogenation. The invention aims to solve the technical problem of how to overcome the defect that in the existing normal propyl alcohol production method, three-phase azeotrope containing propyl propionate, water and normal propyl alcohol can not be recycled. Thus, the process of the invention comprises the following steps: (a) after the three-phase azeotrope is condensed and treated by heat exchange, introducing a pervaporation membrane; (b) condensing gas phase materials separated from the pervaporation membrane to obtain waste water A, mixing the waste water A and raw material propionaldehyde, enabling the mixture to enter a system again, and evacuating residual gas through a vacuum pump; and rectifying liquid phase materials separated from the pervaporation membrane, and separating the normal propyl alcohol and propyl propionate in the liquid phase materials. The invention has the advantages of simple process, convenient operation, environment protection, economization and high normal propyl alcohol yield, and is very suitable for improving product purity, reducing production cost and reducing environment pollution in the existing normal propyl alcohol production enterprises.

Description

technical field [0001] The invention relates to a clean production process for preparing n-propanol by hydrogenating propionaldehyde. Background technique [0002] The Chinese invention patent published on July 23, 2008 with the publication number CN101225018A discloses a "method for removing the by-product propyl propionate in the process of preparing n-propanol by hydrogenation of propionaldehyde", in which the propyl propionate , water and n-propanol form a three-phase azeotrope, this three-phase azeotrope contains about 5%-45% water, 40%-70% n-propanol and 5%-25% propyl propionate, as The light components (raffinate) of the light removal tower, except for part of the reflux, the rest cannot be utilized, and the discharge causes environmental pollution and also causes a lot of waste. (The percentage compositions mentioned in this paper are all mass percentages) Contents of the invention [0003] The technical problem to be solved by the present invention is how to ove...

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Problems solved by technology

[0003] The technical problem to be solved by the present invention is how to overcome the defect that the three-phase azeotrope containing propyl propionate, water and n-propanol cannot be recycled and utilized in the existing n-propanol production method, and provide a kind of n-propanol produced by hydrogenation of propionaldehyde clean production process

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