Method for separating isobutyl alcohol and normal heptanes azeotropic system by using pressure swing distillation

Abstract

The invention relates to a method for separating an isobutyl alcohol and normal heptanes azeotropic system by using pressure swing distillation and a device applicable to the method. The device mainly comprises an atmospheric tower T1, a pressurized tower T2, a condenser C1, a condenser C2, a reflux drum D1, a reflux drum D2, a reboiler R1 and a reboiler R2, wherein the reboiler R1 and the reboiler R2 are respectively connected at the bottoms of the atmospheric tower T1 and the pressurized tower T2, the condenser C1 and the reflux drum D1 are sequentially connected at the top of the atmospheric tower T1, the condenser C2 and the reflux drum D2 are sequentially connected at the top of the pressurized tower T2. The separation steps are as follows: a fresh material first enters into the atmospheric tower T1, an isobutyl alcohol product is extracted at the bottom of the tower, after being condensed through the condenser C1, and collected through the reflux drum D1, part of overhead vapor is back flowed, part of the extract enters into the pressurized tower T2 for a secondary rectification, a normal heptanes product is extracted at the top of the pressurized tower T2, and the material flow at the bottom of the tower cycles to the atmospheric tower T1. The method provided by the invention solves the difficult separation problem that the azeotropic behaviors of the system respectively show up a lowest feature and a highest feature along with the raising pressure, and has the advantages of low energy consumption and high product recovery rate.

Description

technical field [0001] The invention belongs to the field of separation and purification in the chemical industry, and specifically relates to a method for separating the azeotropic system of isobutanol and n-heptane by pressure swing rectification, and is especially suitable for separating the azeotropic behavior of isobutanol and n-heptane with the pressure increasing. Boiling binary azeotrope system of isobutanol and n-heptane. Background technique [0002] Isobutanol and n-heptane are important chemical raw materials, which are widely used in pharmaceutical, rubber, spray paint and other industries. Industrially, in the process of producing tris(2-methylpropyl) vanate, the effective separation of isobutanol and n-heptane has great economic benefits for enterprises. [0003] Because the isobutanol and n-heptane system can form an azeotrope under normal pressure, a special distillation method is required to separate the mixture of the two. Commonly used special distillat...

AI Technical Summary

Problems solved by technology

[0013] In view of the characteristics of the current traditional pressure swing rectification process and the problem that the isobutanol and n-heptane systems exhibit different azeotropic behaviors with pressure changes, the scientific problems to be solved by the patent of the present invention are as follows:

Images