Crystallization of sodium phenylpyruvate (PPNa) by hydrolysis of 5-benzalhydantoin in alkaline solution is studied. In order to increase the yield and purity of product, the method of controlled crystallization is sudied. At first, different type of acids are used for neutralization and then the solubility of sodium phenylpyruvate in alkaline solution is analysed. It is found that hydrochloric acid is better for the yield and purity of PPNa and the optimum volume of HCl used is selected. During crystallization, if velocity of acid dropping, velocity of agitation and time of crystallization are controlled in certain way, uniform and pure product can be obtained. The yield of PPNa crystallization is about 91.7% and the purity of product is about 98.5%.%研究了碱性溶液中苯丙酮酸钠盐的结晶过程。在分析苯丙酮酸钠盐在碱性溶液中溶解度的基础上，通过对中和用酸的选择、加酸过程和搅拌速度的控制，以及结晶时间的选择，得到了优化的结晶工艺。苯丙酮酸钠盐的结晶收率达到91.7%，纯度达到98.5%。
展开▼
