Title:
METHOD FOR CONTROLLING ANILINE IMPURITIES THAT ARE DIFFICULT TO TREAT IN WASTE BRINE IN DAM PRODUCTION PROCESS
Document Type and Number:
WIPO Patent Application WO/2024/021969
Kind Code:
A1
Abstract:
The present invention provides a method for controlling aniline impurities that are difficult to treat in waste brine in a DAM production process, the method comprising the following steps: (1) in the presence of an iron-molybdenum catalyst, reacting methanol with fresh air to prepare a formaldehyde-containing reaction gas, cooling same, and then absorbing same with pure water to obtain a raw material – aqueous formaldehyde solution for producing DAM; (2) in the presence of an acid catalyst, carrying out a condensation reaction, a transposition rearrangement reaction and an acid-base neutralization reaction on the prepared aqueous formaldehyde solution and aniline to obtain a brine phase containing a diphenylmethane-based diamine and polyamine and an organic phase; and (3) carrying out extraction and steam stripping treatment on the brine phase to obtain waste brine; and purifying and refining the organic phase to obtain the diphenylmethane-based diamine and polyamine, wherein in step (1), the content of ethanol in the methanol is less than or equal to 100 ppm, the molar ratio of oxygen to alcohol is 0.9-1.3, and the reaction pressure is less than or equal to 1.9 bara. By means of the method of the present invention, the content of aniline impurities that are difficult to treat in waste brine in a DAM production process is reduced to 0.3 ppm or below, so that requirements for a subsequent treatment are satisfied.
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Inventors:
XU DAN (CN)
LI YONGFENG (CN)
LI CHAOQUN (CN)
GENG WENJIE (CN)
WANG PUZHAO (CN)
WU XUEFENG (CN)
ZHANG HONGKE (CN)
LI YONGFENG (CN)
LI CHAOQUN (CN)
GENG WENJIE (CN)
WANG PUZHAO (CN)
WU XUEFENG (CN)
ZHANG HONGKE (CN)
Application Number:
PCT/CN2023/103131
Publication Date:
February 01, 2024
Filing Date:
June 28, 2023
Export Citation:
Assignee:
WANHUA CHEMICAL GROUP CO LTD (CN)
International Classes:
C07C209/78; C02F1/02; C02F1/26; C07C47/052; C07C209/74; C07C211/50; C02F101/38; C02F103/36
Foreign References:
| CN112126030A | 2020-12-25 | |||
| CN112094194A | 2020-12-18 | |||
| CN112250584A | 2021-01-22 | |||
| CN114315598A | 2022-04-12 | |||
| CN101143753A | 2008-03-19 | |||
| CN104193605A | 2014-12-10 | |||
| CN110790646A | 2020-02-14 | |||
| CN112225678A | 2021-01-15 | |||
| JP2015166322A | 2015-09-24 | |||
| US20120168375A1 | 2012-07-05 |
Attorney, Agent or Firm:
SINO-CREATIVITY INTELLECTUAL PROPERTY LAW FIRM (CN)
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