Method for separating acetic acid from water by acetic acid dehydration tower

Abstract

The invention relates to a method for separating acetic acid from water by an acetic acid dehydration tower, which mainly solves the problems of high energy consumption and high equipment manufacturing cost in an acetic acid dehydration process in the prior art. In the invention, distillation and dehydration are carried out by pressurizing the acetic acid dehydration tower, water is used as a heat exchange medium in heat pump circulation, the heat released by condensing the discharged material at the top of the acetic acid dehydration tower is absorbed by a heat exchange medium in a closed heat pump process, the heat exchange medium after absorbing the energy of the discharged material at the top of the tower is compressed by a compressor so as to raise temperature, the high-temperature superheated steam is firstly desuperheated by a desuperheater to form saturated steam, and then the saturated steam is transferred into a tower kettle reboiler to carry out heat exchange with the discharged material at the bottom of the tower; and the steam subjected to heat exchange in the tower kettle enters a gas-liquid separation tank after throttling decompression, the separated liquid phase enters a condenser at the top of the tower to carry out heat exchange, and the separated gas phase is mixed with the gas at the outlet of the condenser at the top of the tower to enter the compressor, thereby being used for carrying out heat exchange again with the tower kettle. The technical scheme provided by the invention better solves the problems and can be applied to industrial production for separating acetic acid from water.

Description

technical field [0001] The invention relates to a method for separating acetic acid and water in an acetic acid dehydration tower. Background technique [0002] In the process of oxidizing p-xylene to produce terephthalic acid, acetic acid is usually used as an organic solvent. The large amount of water formed during the oxidation dilutes the acetic acid solvent, which is required in the appropriate concentration for the reaction. In order to ensure the concentration of acetic acid in the solvent, an acetic acid dehydration tower is usually used to separate the excess water in the solvent. With the expansion of production scale, the operating cost of acetic acid dehydration tower is increasing day by day. [0003] Conventional direct rectification dehydration due to relatively low volatility when the concentration of acetic acid is low, the method of increasing the number of trays and increasing the reflux ratio is usually used to reduce the concentration of acetic acid in...

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Problems solved by technology

[0007] The technical problem to be solved by the present invention is the problems of high energy consumption, high equipment manufacturing cost and high operating cost in the acetic acid dehydration process in the prior art, and a new method for separating acetic acid and water in the acetic acid dehydration tower is provided

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