METHOD FOR CONTROLLING TOC IN EFFLUENT BRINE IN DAM PRODUCTION PROCESS

WIPO Patent Application WO/2022/067747

A1

Provided is a method for controlling TOC in effluent brine in a DAM production process, the method comprising the following steps: (1) subjecting formaldehyde and aniline to a condensation reaction and a transposition rearrangement reaction in the presence of an acidic catalyst, to obtain a mixture containing a diphenylmethane-based diamine salt and polyamine salt; (2) adding an alkali solution to the mixture for a neutralization reaction, followed by layering, to obtain a brine phase I and an organic phase I containing the diphenylmethane-based diamine and polyamine; and (3) subjecting the brine phase I to extraction and stripping treatments, to obtain an effluent brine, wherein the organic phase I is subjected to purification and refining treatments, to obtain the diphenylmethane-based diamine and polyamine, wherein, in step (1), the molar ratio of formaldehyde to aniline is 0.3-0.6, and the total content of impurities in the formaldehyde is less than 1000 ppm and in step (2), the excess base ratio in the neutralization reaction is 1.01-1.30. By means of the method of the present invention, the TOC content in effluent brine is reduced to 15 ppm, which meets the requirements of subsequent treatments.

ZHANG LIANG (CN)
LI YONGFENG (CN)
XING JINMING (CN)
WU XUEFENG (CN)
ZHANG HONGKE (CN)
CUI CHENGCHENG (CN)
CHEN LIANGJIN (CN)
ZHAO YIBING (CN)

PCT/CN2020/119621

April 07, 2022

September 30, 2020

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WANHUA CHEMICAL GROUP CO LTD (CN)
WANHUA CHEMICAL NINGBO CO LTD (CN)

C07C209/78; C07C211/50; C07C209/84

CN107827756A	2018-03-23
CN111056953A	2020-04-24
CN101679203A	2010-03-24
CN101665302A	2010-03-10

SINO-CREATIVITY INTELLECTUAL PROPERTY LAW FIRM (CN)

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