摘要
采用选择性溶剂化模型和定标粒子理论计算了8种盐类萃取剂在醋酸甲酯-甲醇-水三元体系中的标准摩尔溶剂化自由能,引入盐的溶解参数进行修正,并结合萃取分离实验进行验证,结果表明,随着盐的标准摩尔溶剂化自由能绝对值的增大,有机相中酯的质量分数呈线性增大,而有机相中水的质量分数则呈线性降低。静电相互作用力是影响加盐萃取效果的主要原因,盐与水(或醇)分子之间的静电自由能绝对值越大,盐对酯的萃取效果越好。采用标准摩尔溶剂化自由能的计算值可从理论上定量选择适宜的盐类作为萃取剂。
It is very difficult to select the salt in salt-containing extraction,which has been widely applied in chemical separation processes.In this study,ionic solvation free energies of eight salts in methyl acetate/methanol/water system at 25℃ were calculated by means of selective solvation model and scaled particle model revised by the solubility parameter of salt.The calculated values were verified by extraction separation experiment.The results indicate that the mass fraction of acetate in the organic phase increases linearly with the absolute value of the ionic solvation free energy of salt,while that of water in the organic phase decreases linearly.The electrostatic interaction force is the major factor influencing the effect of salt-containing extraction.When the absolute value of the electrostatic interaction free energy between the salt molecule and water molecule or methanol molecule is larger,the extraction effect of salt on ethyl acetate is better.Furthermore,the method of the ionic solvation free energy can be applied in qualitative selection for proper salt as extractant.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2010年第6期1475-1481,共7页
CIESC Journal
基金
广东省自然科学基金项目(8351064101000002)~~
关键词
定标粒子理论
加盐排斥萃取
溶剂化自由能
盐效应
scaled particle theory
salt-containing extraction
ionic solvation free energies
salt effect
