MVR (mechanical vapor recompression) concentration and rectification system and recovery method for DMAC (dimethylacetamide) waste liquid

Abstract

The invention relates to the technical field of DMAC waste liquid treatment, in particular to a DMAC waste liquid MVR concentration and rectification system which comprises a first concentration tower, a second concentration tower, a rectification tower, a deacidification tower, a flash tank, a feed heater, a condenser, a DMAC reflux tank and a DMAC finished product tank. A material outlet of a waste liquid tank in the tank area is connected with a material inlet of the first concentration tower through a waste liquid pump, a material outlet of the first concentration tower is connected with a material inlet of the second concentration tower through a discharging pump, and a material outlet of the second concentration tower is connected with a liquid phase material inlet of the flash tank through the discharging pump. According to the invention, DMAC is concentrated within 100 DEG C, and rectification and deacidification are carried out within 100 DEG C, the whole process is completely carried out at a low temperature, DMAC is basically not decomposed, and the final DMAC decomposed product dimethylamine is extremely low in content in the atmosphere, meets the emission standard and can be discharged up to the standard; and the content in water at the top of the tower is less than 40ppm, so that the water can be reused in a production line, and air pollution and water pollution are thoroughly solved.

Description

technical field [0001] The invention relates to the technical field of DMAC waste liquid treatment, in particular to an MVR concentration and rectification system for DMAC waste liquid and a recovery method. Background technique [0002] DMAC, also known as N,N-dimethylacetamide, is an excellent organic solvent, widely used in medicine, battery, membrane industry, textile industry and other industries, and DMAC waste liquid is produced during use. Because DMAC is a kind of antibacterial agent, it will also kill the activated sludge in the sewage treatment tank at a low concentration, so there is no good way to treat DMAC waste liquid by biochemical treatment. In addition, from an economic point of view, it is the best choice to use rectification to treat DMAC waste liquid. At present, there are many rectification and recovery methods for DMAC waste liquid in China, but there are two common problems: ①Environmental protection: the product of DMAC pyrolysis Methylamine, dimet...

AI Technical Summary

Problems solved by technology

Since DMAC is a bacteriostatic agent, it will also kill the activated sludge in the sewage treatment tank at a low concentration, so there is no good way to treat DMAC waste liquid by biochemical treatment.

In addition, from an economic point of view, it is the best choice to use rectification to treat DMAC waste liquid. At present, there are many rectification and recovery methods for DMAC waste liquid in China, but there are two common problems: ①Environmental protection: the product of DMAC pyrolysis Methylamine, dimethylamine are toxic and have a foul smell

In recent years, various methods have been adopted to effectively solve the pollution problem of dimethylamine. With the establishment of the Environmental Protection Law, the problem of dimethylamine has attracted more and more attention from the Environmental Protection Bureau and enterprises, and a good solution is urgently needed. Solving the Dimethylamine Problem

②Energy consumption: Both direct distillation and multi-effect concentrated distillation have the problem of high energy consumption

There are two problems in adopting this recovery method: 1. environmental protection: because the technological process is too long, the residence time of DMAC in the system is too long. Around 200ppm

The energy consumption of the system is relatively high due to the failure to adopt the method of MVR concentration to dehydrate 18t / h

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