A process of taurine preparation with ethanolamine is divided into two parts

esterification reaction and sulfonation reaction. (NH4)2SO3 was used as sulfonating agent. Sulfonation conditions in the presence of ammonia gas were optimized to be reaction temperature 105℃

reaction time 12 h

material ratio of (NH4)2SO3 to 2-aminoethyl hydrogen sulfate 1.65

and 4 times of batch feeding. Under these conditions

the conversion rate of 2-aminoethyl hydrogen sulfate was 76.43%. The separation technique for the mixed solution of sulfonated reaction was investigated. Firstly

inorganic salt (NH4)2SO4

which is one of products

was removed by chemical precipitation. After filtering out the sediment sulfate MeSO4

the liquor was slightly heated

so that another resultant NH3·H2O was decomposed into ammonia gas and water. Experimental results show that the desalination rate is over 98% by this method. Secondly

the solvent crystallization method was used for separation of the liquid mixture containing taurine and 2-aminoethyl hydrogen sulfate. The influences of crystallization temperature

crystallization time

cooling rate and stirring rate on crystallization process were examined by uniform design method. The optimum crystallization conditions were found as follows: crystallization temperature 13.9℃

crystallization time 1 h

cooling rate 0.5℃·min-1 and stirring speed 350—450 r·min-1. The crystallization yield of taurine was 67.94% and its purity was almost 100%.