N,N-dimethylacetamide wastewater recovery process

Abstract

The invention discloses a recovery process of wastewater containing N,N-dimethylacetamide, which comprises the following steps: adding a small amount of azeotrope, agent N,N-dimethylacetamide, into awater removal tower to obtain water with the purity of more than 99.9% at the tower top, feeding N,N-dimethylacetamide and acetic acid at the tower bottom into a pressurizing tower to obtain acetic acid with the purity of 99.5% at the tower top and N,N-dimethylacetamide, feeding the N,N-dimethylacetamide mixed solution into a vacuum tower, obtaining 99.8% of N,N-dimethylacetamide from the top of the tower, and circulating the material flow at the bottom of the tower back to the pressurizing tower, wherein the top steam of the dehydration tower is used for preheating fed materials, and the topsteam of the pressurization tower directly exchanges heat with a bottom reboiler of the decompression tower. Compared with the prior art, the process has the advantages that introduction of alkaline substances is avoided, the product recovery rate is high, the energy consumption is low, and the practicability is high.

Description

technical field [0001] The invention belongs to the technical field of chemical separation and purification, and in particular relates to a process for recovering N,N-dimethylacetamide wastewater. Background technique [0002] N,N-Dimethylacetamide is an important basic chemical raw material with good solubility and is widely used as an additive in medical, textile, coating and other industries. At present, the production process of N,N-dimethylacetamide mainly includes acid anhydride method, acetyl chloride method and acetic acid method. The acetic acid method uses acetic acid and dimethylamine as raw materials to synthesize N,N-dimethylacetamide. This method has energy It has the advantages of low consumption, high economic benefit, suitable for continuous large-scale production, etc. It is the main method for domestic production of N,N-dimethylacetamide. During the production of N,N-dimethylacetamide by the acetic acid method, a large amount of N,N-dimethylacetamide / acet...

AI Technical Summary

Problems solved by technology

Although the above technologies all disclose the recovery scheme of N,N-dimethylacetamide wastewater, the addition of alkaline substances cannot be avoided in the existing technologies, and acetic acid is removed by neutralization, which has the disadvantages of large consumption of alkali and complicated processes. question

Images