US 11,891,355 B2
Method for preparing taurine and method for recovering mother liquor thereof
Xiaoxiang He, Shaoxing (CN); Junhua Peng, Shaoxing (CN); Xianghua Yao, Shaoxing (CN); Songhua Xu, Shaoxing (CN); Lihuan Cheng, Shaoxing (CN); Yinbing Wang, Shaoxing (CN); Yinjiang Song, Shaoxing (CN); and Lei Wang, Shaoxing (CN)
Assigned to ZHEJIANG NHU COMPANY LTD., Shaoxing (CN); ZHEJIANG NHU PHARMACEUTICAL CO., LTD., Shaoxing (CN); and SHANGYU NHU BIO-CHEM CO., LTD., Shaoxing (CN)
Appl. No. 17/618,887
Filed by ZHEJIANG NHU COMPANY LTD., Shaoxing (CN); ZHEJIANG NHU PHARMACEUTICAL CO., LTD., Shaoxing (CN); and SHANGYU NHU BIO-CHEM CO., LTD., Shaoxing (CN)
PCT Filed Nov. 17, 2020, PCT No. PCT/CN2020/129421
§ 371(c)(1), (2) Date Dec. 14, 2021,
PCT Pub. No. WO2021/120957, PCT Pub. Date Jun. 24, 2021.
Claims priority of application No. 201911312305.5 (CN), filed on Dec. 18, 2019.
Prior Publication US 2022/0371992 A1, Nov. 24, 2022
Int. Cl. C07C 303/44 (2006.01); C07C 303/22 (2006.01); C07C 303/32 (2006.01)
CPC C07C 303/44 (2013.01) [C07C 303/22 (2013.01); C07C 303/32 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method for recovering a taurine mother liquor, comprising:
A1, providing a taurine mother liquor, and mixing the taurine mother liquor and a treating agent to obtain a solid-containing suspension, wherein the treating agent is a water-soluble organic solvent or a mixture of the water-soluble organic solvent and water;
A2, filtering the suspension to obtain a first solid product and a first filtrate; and
A3, dissolving the first solid product with an ammonia source to obtain a first mixture, and then filtering the first mixture to obtain a second solid product and a second filtrate,
wherein the taurine mother liquor is a solution containing impurities comprising taurine, sodium taurate, sodium ditaurate, sodium tritaurate, sodium isethionate, organic impurities and inorganic impurities,
the organic impurities comprise ethanediol, polyethylene glycol, and polyether, and the inorganic impurities comprise sulfates,
in step A3, before dissolving the first solid product in the ammonia source, the method further comprises:
drying the first solid product to make a mass fraction of the organic solvent in the first solid product less than or equal to 2%,
the ammonia source in step A3 comprises a saturated ammonium hydroxide, and
in step A3, the mass of the ammonia source is 4 times to 15 times of a mass of the dried first solid product.