Technology process for recovering spandex DMAC (Dimethylacetamide) solvent

Abstract

The invention relates to a technology process for recovering a spandex DMAC (Dimethylacetamide) solvent, and in particular relates to a technology process in which the tetrachloroethylene is adopted and used as an azeotrope agent to carry out azeotropic distillation and separation to DMAC and acetic acid. The technology process comprises the following steps: adding tetrachloroethylene and a DMAC-acetic acid mixed solvent to an azeotropic distillation tower together, thus obtaining an acetic acid-tetrachloroethylene azeotrope from the top of the azeotropic distillation tower; condensing and cooling; reflowing part of the azeotrope to the azeotropic distillation tower; and transferring the other part of the azeotrope to a split-phase tank; adding water to the split-phase tank; stirring; standing for layering, wherein the tetrachloroethylene is generated at the lower layer and can be recycled, the acetic acid-water solution at the upper layer can be rectified and separated to obtain an acetic acid product; and continuously rectifying after the tetrachloroethylene and the acetic acid in the azeotropic distillation tower are completely discharged, thus obtaining the qualified DMAC product from the top of the azeotropic distillation tower. By adopting the technology process, the DMAC and the acetic acid can be completely separated, so that the pollution of direct drainage to the environment can be avoided, the production cost is reduced, and the social benefit is increased.

Description

technical field [0001] The invention relates to a process method of solvent recovery, in particular to a process method of spandex DMAC solvent recovery, which uses azeotropic distillation to separate DMAC (N,N-dimethylacetamide) and acetic acid mixed solvents in the spandex industry. Background technique [0002] N,N-Dimethylacetamide, referred to as DMAC, is an important organic chemical raw material, a pharmaceutical intermediate, and a solvent with excellent performance. A large amount of mixed solution of DMAC and acetic acid is produced in the production of spandex. How to recover DMAC and acetic acid economically and effectively is very important to improve the overall economic and social benefits of the enterprise and reduce pollution emissions. [0003] Since DMAC and acetic acid can form the highest azeotrope, and the azeotropic composition is DMAC: acetic acid = 76:24, it is impossible to completely separate the two through ordinary distillation. [0004] The con...

AI Technical Summary

Problems solved by technology

The main disadvantage of this process is: as the main solvent DMAC in the product

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