Phase Equilibria for the Glycine-Methanol-NH4Cl-H2O System
Phase Equilibria for the Glycine-Methanol-NH4Cl-H2O System
复制标题
甘氨酸-甲醇-NH4Cl-H2O 系统的相平衡
DOI：
10.1021/ie502846m
复制
发表时间：
2014
影响因子：
4.2
通讯作者：
Demopoulos George P.
中科院分区：
文献类型：
--
作者：
Zeng Yan;Li Zhibao;Demopoulos George P.
研究了甘氨酸-甲醇-NH_4Cl-H_2 O体系的相平衡，以优化一氯乙酸（MCA）生产甘氨酸的工艺。测定了甘氨酸-NH_4Cl-H_2 O体系在283.2-353.2 K温度范围内的相平衡，其浓度范围可达多个饱和点。甘氨酸和NH 4Cl的溶解度被认为是随着温度的升高而增加，以及与其他溶质的浓度增加。在OLI平台中实施的离子的Bromley-Zemaitis模型和甘氨酸中性物质的Pitzer公式用于实验溶解度的回归。甘氨酸和氯化铵的溶解度值与实验值的平均绝对偏差分别为1.4%和0.93%。新获得的Pitzer配方的三个二元相互作用参数，并与记录在OLI的数据库中的Bromley-Zemaitis参数相结合，以预测系统的多个饱和点。此外，甘氨酸在甲醇-水混合物中的溶解度也测量了从283.2至323.2 K，并观察到作为甲醇含量的函数急剧下降。这种热力学信息对于改进现有的工业过程以及为开发新的甘氨酸生产过程提供基础是绝对有用的。
An investigation of the phase equilibria of the glycine–methanol–NH4Cl–H2O system was carried out with the objective of optimizing the monochloroacetic acid (MCA) process for the production of glycine. Phase equilibrium of the glycine–NH4Cl–H2O system at temperatures over the range of 283.2–353.2 K was determined for concentrations ranging up to the multiple saturation points. The solubilities of both glycine and NH4Cl were found to increase with increasing temperature, as well as with increasing concentration of other solutes. The Bromley–Zemaitis model for ions and the Pitzer formulation for glycine neutral species implemented in the OLI platform were used in the regression of the experimental solubilities. The average absolute deviations between the regressed solubility values and the experimental data were found to be 1.4% for glycine and 0.93% for NH4Cl. Three binary interaction parameters of the Pitzer formulation were newly obtained and coupled with the Bromley–Zemaitis parameters documented in OLI’s databank to predict the multiple saturation points of the system. Additionally, the solubility of glycine in methanol–H2O mixtures was also measured from 283.2 to 323.2 K, and a sharp decline was observed as a function of the content of methanol. Such thermodynamic information is definitely useful for improving the existing industrial process, as well as providing fundamentals for the development of new glycine production processes.