DMAC, DMF or DMSO waste solution dehydrated refining recovery process and system

Abstract

The invention discloses a DMAC, DMF or DMSO waste solution dehydrated refining recovery process and system. A waste solution is preheated by a feeding preheater and continuously feeds from a falling-film evaporator; the waste solution is heated by the falling-film evaporator and then is subjected to gas-liquid separation in a gas-liquid separation chamber; a vapor phase enters a MVR concentratingtower; an MVR heat pump group pressurizes and heats waste solution steam generated by the MVR concentrating tower to serve as a heat source of the falling-film evaporator; the concentration of a low-concentration waste solution delivered to an MVR concentration unit is improved; the low-concentration waste solution of which the concentration is improved is delivered to a dehydration unit for dehydrating; the MVR concentration unit and the dehydration unit extract wastewater which is fed into a steam stripping de-light unit and a steam stripping de-light tower; by one-time steam heating, steamrising to the tower top is condensed and refluxed by a condenser of the steam stripping de-light tower; an evaporation de-heavy unit and a crude product unit extract reboiling substances which are fedinto a reboiling treatment unit. The DMAC, DMF or DMSO waste solution dehydrated refining recovery process and system disclosed by the invention carry out solvent recovery on the low-concentration waste solution so as to remove contained trace metal ions.

Description

technical field [0001] The invention relates to a waste liquid dehydration refining recovery process and system, in particular to a waste liquid dehydration refining recovery process and system applicable to low-concentration DMAC, DMF or DMSO and the like. Background technique [0002] The scientific name of DMAC is dimethylacetamide. In organic synthesis, dimethylacetamide is an excellent catalyst, which can accelerate reactions such as cyclization, halogenation, cyanation, alkylation and dehydrogenation, and can increase the yield of main products. Rate. In the production of some medicines and pesticides, dimethylacetamide can also be used as a solvent or cocatalyst. Compared with traditional organic solvents, it can improve product quality and yield. [0003] The scientific name of DMF is dimethylformamide. It is not only a chemical raw material with a wide range of uses, but also an excellent solvent with a wide range of uses. Dimethylformamide is a good solvent for v...

AI Technical Summary

Problems solved by technology

[0005] At present, the country pays more and more attention to the ecological problems caused by environmental pollution. During the use of chemical substances such as DMAC, DMF or DMSO, many low-concentration waste liquids containing DMAC, DMF or DMSO will be produced. At the same time, the waste liquid will contain a variety of Trace amounts of metal elements, the direct discharge of these waste liquids into the environment will cause environmental pollution and affect the health of animals and plants

The Chinese patent with the publication number CN107098826A discloses a ten-tower six-effect rectification system and method for DMAC or DMF waste liquid. The patent is provided with a feed preheater, a first concentration tower, a second concentration tower, and a third concentration Tower, fourth concentration tower, fifth concentration tower, sixth concentration tower, rectification tower, deacidification tower, acetic acid (formic acid) decomposition tower, deamination tower, flash tank, dryer and gas-water separation tank, incinerator, Although this patent can recover the contained DMAC or DMF, it is not suitable for the treatment of DMAC, DMF or DMSO waste liquid with low concentration, such as low concentration solution with solvent concentration of 3-15%, and the recovered product contains trace amounts during the treatment process. How to deal with DMAC, DMF or DMSO or similar waste liquid containing low concentration and metal elements is an urgent problem to be solved

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