谷氨酸间歇等电结晶研究Ⅰ:调酸速率的控制

Strategic Study on Batch Iso-electronic Crystallization of Glutamic Acid Ⅰ Rate of Neutralizing Acid

谷氨酸工业结晶过程中,控制合理的调酸速率、结晶温度及晶种添加,是实现高提取收率、高结晶质量的关键。文中根据谷氨酸在发酵液中的溶解度曲线,将等电结晶过程分为5个阶段,并重点探讨了Ⅲ、Ⅳ两个阶段调酸速率对结晶的影响。结果表明,低调酸速率有利于结晶生长,当Ⅲ、Ⅳ两个阶段的最适调酸时间分别控制为8、4 h时,等电母液残留谷氨酸浓度降至18.5 g/L,提取收率达到84.4%,结晶质量良好。

During the crystallization process of glutamic acid, the key to achieve the high extraction rate and good crystalline quality is to control the reasonable neutralizing acid speed, crystallization temperature and seeds addition. In this paper, the process of iso-electronie crystallization was divided into five stages based on the solubility curve of glutamic acid in the fermentation broth. The main goal of the Ⅲ and Ⅳ stages was investigating the influence of neutralizing acid rate on crystallization. The results showed that a lower rate of neutralizing acid was in favor of the crystalline growth; and that when the optimal times of the two stages （ Ⅲ and Ⅳ ） were controlled at 8 and 4 h, respec- tively. The glutamic acid remained in the iso-electronic mother liquor was only at 1.85 g / 100 mL and the extraction rate reached 84.4% , with a good crystalline quality.