三辛胺萃取分离乳酸-醋酸

SEPARATION OF LACTIC ACID AND ACETIC ACID WITH TOA BASED ON CHEMICAL COMPLEXATION

选择三辛胺为络合剂、正辛醇为稀释剂、乳酸和醋酸为被萃溶质 ,系统地研究了水相pH值及络合剂含量对单组分乳酸、醋酸及其混合物萃取特性的影响。在适当假设条件的基础上 ,建立了考虑络合萃取及物理萃取的单组分及双组分体系的相平衡分配系数表达式。在本文的实验条件下 ,随络合剂含量的升高 ,乳酸、醋酸的单组分及其混合物中各组分相平衡分配系数皆升高 ,分离因子 β增大 ;随水相平衡pH值的升高 ,相平衡分配系数均降低 ,分离因子也呈下降的趋势 .采用本文的模型进行模型参数拟合 ,其精度较好。

In this paper, tri-octylamine (in octanol) was selected as extractant to extract lactic acid and acetic acid. The effects of the extractant content and the pH on the extraction equilibrium have been investigated for lactic acid, acetic acid and their mixture. The models of the distribution coefficient were proposed for the single component and the mixture based on some assumptions. At the conditions of the experiment, the distribution coefficients for the single acid and their mixture and the separation factor increased with the content of the extractant, and decreased with the pH. The distribution coefficient models fitted in well with the experimental data, and the complexation reaction constant K 11 for single acid system can be used to predict the distribution coefficient of the mixture.