Patent ID: 9428451
Filing Date: 2016-08-30
CPC Classification: C07C

Claim Text:
1. A cyclic process for the production of taurine from alkali isethionate, comprising, (a) adding an excess of ammonia to a solution of alkali isethionate and subjecting the solution to ammonolysis reaction in the presence of one or more catalysts to yield a mixture of alkali taurinate, alkali ditaurinate, alkali tritaurinate, and unreacted alkali isethionate; (b) recovering the excess ammonia from (a) and neutralizing the solution with sulfuric acid to obtain a crystalline suspension of taurine in a solution of alkali sulfate, alkali ditaurinate, alkali tritaurinate, and alkali isethionate; (c) separating taurine from (b) to provide a mother liquor (d) adjusting the pH of the mother liquor to basic to convert taurine present in the mother liquor to alkali taurinate and prevent the crystallization of taurine, and removing alkali sulfate from the mother liquor by performing evaporative crystallization and cooling crystallization through solid-liquid separation; (e) returning the mother liquor of (d) to (a) for further ammonolysis of alkali ditaurinate, alkali tritaurinate, and unreacted alkali isethionate.