A heat pump assisted pressure swing rectification method for separating benzene and isobutanol mixture

Abstract

The invention discloses a method for separating benzene and isobutanol mixture by heat pump-assisted pressure swing rectification, which mainly uses mechanical vapor recompression heat pump and heat integration technology, and the steps are: after preheating the benzene and isobutanol raw material liquid , enter the low-pressure distillation tower from the top of the tower, and the high-purity isobutanol product is extracted from the bottom of the tower, and the vapor phase at the top of the tower is preheated and compressed to high temperature and high pressure, and then enters the high-pressure rectification tower from the bottom of the tower, and the high-pressure rectification tower The top steam is used as the heat source of the reboiler of the low-pressure distillation column, and the bottom liquid of the low-pressure distillation column is used as the heat sink of the reboiler. The benzene product, the liquid at the bottom of the tower is recycled to the top of the low-pressure stripping column. The invention greatly improves the thermodynamic efficiency and economy of the separation process of the mixture of benzene and isobutanol, and realizes the purpose of energy saving and emission reduction.

Description

technical field [0001] The invention belongs to the technical field of separation and purification in the chemical industry, and specifically relates to an energy-saving method for separating binary azeotropes by heat pump-assisted pressure-swing distillation, especially suitable for special systems such as benzene and isobutanol, that is, forming the maximum azeotrope under high pressure The lowest azeotrope is formed under low pressure, which can be extended to other similar systems. Background technique [0002] Benzene is the simplest aromatic hydrocarbon. It is a colorless, sweet, aromatic and oily transparent liquid at room temperature. Its density is lower than that of water and it is insoluble in water. It has good solubility, so it is widely used. For adhesives and industrial solvents. It is an important petrochemical basic raw material for the synthesis of dyes, rubber, resins, fibers, plastics, medicines, pesticides, films and petrochemical products. [0003] Is...

AI Technical Summary

Problems solved by technology

The vapor recompression heat pump technology reported in this patent belongs to the self-heat recovery technology. The compressor setting is the same as the internal heat integration technology. The whole process can save a lot of energy, but the separated n-butanol-isobutanol mixture belongs to binary non-azeotropic system

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