Absorption distillation method for using adsorption resin to treat waste water containing dimethyl formamide

Abstract

The invention provides an absorption distillation method for using adsorption resin to treat waste water containing dimethyl formamide, belonging to the technical field of treatment of waste water containing dimethyl formamide, and solving the defects of the multi-column distillation and extraction-distillation process in prior art. The absorption distillation method for using adsorption resin totreat the waste water containing dimethyl formamide comprises the steps of using macroporous absorption resin to absorb before distillation of the waste water containing dimethyl formamide, using desorption agent to desorbing the resin, getting the mixed liquid of dimethyl formamide DMF and the desorption agent, delivering the mixed liquid into a rectifying column to implement normal pressure separation or reduced pressure separation, and getting the distillated dimethyl formamide DMF from the bottom of the rectifying column. Compared with the prior art of DMF waste water energy-saving recovery, the invention further reduces DMF recovering energy consumption without causing secondary pollution under the condition of ensuring high DMF recovery ratio, and has good practicality and economic performance.

Description

technical field [0001] The invention belongs to the technical field of dimethylformamide wastewater treatment, and more specifically relates to an adsorption rectification method for treating dimethylformamide wastewater with an adsorption resin. Background technique [0002] N, N-dimethylformamide is a colorless, transparent and stable chemical solvent, which can be miscible with various organic compounds such as water, alcohol, ether, ester, etc., also known as "universal solvent"; it is widely used in the synthesis of polyurethane Leather industry and pharmaceutical, chemical, petroleum, pesticide and other industries. Because DMF is used as a solvent in large quantities in tanning production, the discharged wastewater contains DMF, and DMF has low toxicity to the human body. Therefore, how to effectively and energy-savingly recover DMF from N,N-dimethylformamide wastewater is of great importance to reduce production costs. And energy consumption, protecting the environm...

AI Technical Summary

Problems solved by technology

At present in my country's factories, the method of ordinary rectification is mainly used to reclaim DMF. This process consumes a lot of energy and the recovery cost is high; so many researchers have done a lot of work on the energy-saving aspect of the DMF recovery process. Typical examples include: Pressure rectification or multi-tower operation to reduce energy consumption, among which the double-tower energy-saving process can save energy by about 35% compared with single-tower rectification; (2) The method of combining extraction and rectification to recover DMF can save energy by about 60%.

Although these two processes have good energy-saving effects, both of them have their shortcomings. The vacuum distillation or multi-column distillation process still needs to evaporate a large amount of water and cannot fundamentally reduce energy consumption. However, although the extractant with low boiling point and low latent heat of vaporization is used in the extraction-distillation process, a large amount of extractant is required to ensure the extraction effect, which makes the energy consumption of the rectification separation still have room for reduction. The extraction waste liquid after extraction needs to be further treated, which is likely to cause secondary pollution

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