亚硫酸铵磺化2-氨基乙醇硫酸酯制备牛磺酸及其结晶过程的研究

用亚硫酸铵作为磺化剂,对乙醇胺法合成牛磺酸的关键过程磺化反应进行了研究.用单因素试验和正交试验设计法进行实验,优化出合成牛磺酸的条件为:反应温度为105℃,反应时间为12h,物料配比(n(NH4)2SO3:(.))为1.65.在此条件下2-氨基乙醇硫酸酯的转化率达到70.43％.该工艺具有成本低、后续分离较容易的优点.同时对牛磺酸的结晶条件进行了研究,采用自制溶解-结晶测定装置,并以激光辅助测定技术,测定了在不同温度、不同pH值和不同搅拌速度下2-氨基乙醇硫酸酯和牛磺酸在10％乙醇水溶液中的溶解和超溶解特性,得到二者的结晶介稳区.2-氨基乙醇硫酸酯和牛磺酸的溶解度,均随温度的增大而增大,且pH=6时,两物质的相对溶解度的差值最大,结晶分离操作可在此pH下进行;在相同的结晶条件(10％的乙醇水溶液,中速搅拌,降温速度1℃/15 min,不加晶种)下,牛磺酸的介稳区宽度△e为15～16℃,2-氨基乙醇硫酸酯的介稳区宽度Δe为8～9℃.

Study on the Synthesis Process and Crystallization of Taurine Using Ammonium Sulfite as Sulfonating Agent and 2-Aminoethanol Sulfate as Raw Material

Using ammonium sulfite as sulfonating agent,the key process of taurine production the sulphonating reaction with ethanolamine method was studied.By means of both the single factor and orthogonal experimental design methods,the optimal sulphonating reaction conditions with conversion ratio of 70.43% were found as follows: the reaction time of 12 h,the molar ratio between ammonium sulfite and 2-aminoethanol sulfate of 1.65 and the sulphonating reaction temperature of 105℃.The process proposed has the advantages of low cost and easier follow-up separation.Meanwhile,using laser detection technique,the metastability zones of 2-aminoethanol sulfate and taurine in water at different temperatures and pHs under different agitation rates were investigated by studying their saturate and supersaturate characteristics.The results indicate that the saturate solubility and supersaturate solubility of 2-aminoethanol sulfate and taurine increase with the increase of temperature but with different rates.The solubility difference between 2-aminoethanol sulfate and taurine reaches its maximum point when the pH keeps at 6.Under the same crystallization conditions,namely in 10% ethanol aqueous solution,same stirring speed,same cooling rate(1℃/15 min) and no addition of seeds,the metastable zone width of taurine(e) was found to be 15~16℃,while that of 2-aminoethyl sulfate is 8~9℃.