关键词: 牛磺酸, 亚硫酸铵, 脱盐, 结晶, 化学过程

Abstract:

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%.

Key words: taurine, ammonium sulfite , desalination, crystallization, chemical process