Low-concentration acetic acid recovery method

Abstract

This invention relates to a method to recycle acetic acid from fluid containing low-concentration acetic acid. First, directly introduce the vapor containing low-concentration acetic acid into reactor and simultaneously feed complexing agent gas into the reactor to make the acetic acid in the steam and the complexing agent conduct complexation to generate an acetic acid complex whose boiling point is higher than that of acetic acid. Then, after gas liquid separation, the acetic acid complex is discharged from the bottom of the reactor, which is then conducted regeneration and separation to obtained the acetic acid and complexing agent, the acetic acid is recovered and the complexing agent is feedback to the reactor for circulation use. Or, make the acetic acid complex conduct to obtain the other acetic complex which can be directly used .Advantages: short technological process, low apparatus investment, low energy consumption, high acetic acid recovery rate and low acetic acid content in wastewater after recovering process.

Description

Technical field: [0001] The invention relates to a method for recovering acetic acid, in particular to a method for recovering acetic acid from a fluid containing low-concentration acetic acid. Background technique: [0002] Acetic acid is an important chemical product or raw material, and many chemical processes involve the utilization and recovery of acetic acid. It is relatively easy to recover acetic acid under high-concentration conditions. However, how to better recover acetic acid from low-concentration acetic acid solutions is still an important issue in chemical production. It is understood that due to incomplete recycling, a considerable amount of acetic acid is discharged with wastewater every year in the industry. For example, in the production of furfural, the amount of acetic acid discharged every year in the country is about 10,000 tons, and a set of refined products with an annual output of about 350,000 tons. In terephthalic acid (PTA) production plants, the wast...

AI Technical Summary

Problems solved by technology

[0004] The method of above-mentioned reclaiming acetic acid all is to extract acetic acid from the waste water containing acetic acid, and in many chemical production processes, these waste waters containing acetic acid all come by the condensation of water vapor containing acetic acid, therefore, in the recovery process of acetic acid, The above-mentioned methods all have defects such as high energy consumption, complex extraction process, large investment, and low recovery efficiency to varying degrees, especially for the treatment of low-concentration acetic acid wastewater, the recovery effect is even less ideal, and the economic benefits are poor.

Images