摘要
采用基于UNIFAC模型(改进UNIFAC模型)的较严谨的'动态法'替代传统的'静态法',以FORTRAN语言开发了萃取精馏法分离沸点接近液体混合物(含共沸物)的萃取剂筛选和多元气液平衡预测程序.经文献中的乙醇-水体系气液平衡实验数据验证,UNIFAC模型和改进UNIFAC模型的平衡气相组成预测结果平均相对误差分别为3.26%和1.74%,表明所开发的程序具有良好的可靠性和适用性.采用基于改进UNIFAC模型的'动态法'对萃取精馏法分离环己烷-苯混合物的萃取剂进行了计算机高通量筛选,根据适宜萃取剂选取原则和计算结果,经综合考虑选出较好的萃取剂为二氯甲烷和1,2,3-三氯丙烷.选取二氯甲烷做实验验证,测定了环己烷-苯-二氯甲烷分离体系的部分气液平衡实验数据,结果表明实验值与计算值吻合良好.以二氯甲烷作为萃取剂具有能耗低、待分离体系热稳定性好和有效能损失小的优点.
The more rigorous ‘dynamic method＇ instead of ‘static method＇ based on UNIFAC model （modified UNIFAC model） was used to develop a program with FORTRAN language, which can be used to select solvent for extractive distillation separation of azeotropic and close-boiling mixtures and predict multi-component vapor-liquid equilibria （VLE）. Verified by the VLE experimental data of ethanol-water system in the literature, this program gives the average relative deviation between the calculated gas phase equilibrium composition and that of literature 3.26% and 1.74% for UNIFAC model and modified UNIFAC model respectively, which manifests the reliability of this program. The extractive solvents to separate cyclohexane-benzene mixture were screened with high-throughput quantitatively by ‘dynamic method＇ based on modified UNIFAC model, and the better solvents were determined based on the prediction results and feasible solvent selection principle as dichloromethane and 1,2,3-trichloropropane. The VLE data of cyclohexanebenzene-dichloromethane system at 101.325 kPa were measured through experiment, and the calculated VLE data of the systems fit well with experimental data. Dichloromethane as extractive solvent has the advantages of low energy consumption and fine heat stability of the separation system.
出处
《过程工程学报》
EI
CAS
CSCD
北大核心
2007年第4期755-760,共6页
The Chinese Journal of Process Engineering
关键词
改进UNIFAC模型
气液平衡
萃取精馏
共沸物
萃取溶剂
modified UNIFAC model
vapor-liquid equilibria
extractive distillation
azeotropic mixture
extractive solvent
