Method for reutilization of wastewater from DBNPA production

Abstract

The invention discloses a recycling method of DBNPA production wastewater. The DBNPA production wastewater is mixed with raw material CAA, wherein, the weight ratio of the production wastewater to CAA is 150 to 1; the mixture is heated and dissolved, and the dissolving temperature is 90 DEG C to the room temperature; the solution is filtered to remove foreign bodies and is combined with the production wastewater. Bromine is dripped for the reaction to obtain the DBNPA product. The yield of the product is 94 percent and the product is qualified. Simultaneously, the wastewater is reduced by about 300L. The recycling method utilizes the production wastewater (mother liquor) of DBNPA as solvent for dissolving CAA. Then, the filtering is carried out. After the foreign bodies are removed, the filtered solution is combined with the production wastewater to produce DBNPA products. On one hand, the water usage amount can be reduced, and on the other hand, the wastewater treating capacity of DBNPA during the synthesizing process can be reduced, and the liquid yield is improved.

Description

technical field [0001] The invention relates to a method for recycling waste water produced by DBNPA. Background technique [0002] During the survival process of 2,2-dibromo-3-cyanopropionamide (DBNPA), the raw material cyanoacetamide (CAA) can be directly put into the production wastewater (mother liquor) of DBNPA for synthetic production. However, because CAA often contains a large amount of foreign matter, and DBNPA has no process of filtering out foreign matter during the production process, so in the actual production process, CAA often cannot be directly put into the mother liquor for production. [0003] In order to remove the foreign matter contained in the raw material CAA, in the actual production process, water is often used as a solvent to dissolve CAA and then filter. After the foreign matter is removed first, the filtrate is combined with the mother liquor to produce DBNPA. This production method The yield is about 93%. In this production situation, due to t...

AI Technical Summary

Problems solved by technology

In this production situation, due to the increased use of water, the amount of wastewater generated after production is relatively large. Except for some recycling, the rest will be treated as wastewater, which increases production costs.

At the same time, due to the increase in the amount of water used, this part of the water has dissolved part of the DBNPA, thus resulting in a decline in the yield