摘要
乙腈和水在一定压力下可形成具有最低温度的共沸混合物,普通精馏方法无法将其有效分离,必须采用萃取精馏等特殊分离技术。鉴此,通过实验测定乙腈+水+1-乙基-3-甲基咪唑乙醇酸盐([EMIM][GAC])三元汽液平衡(VLE)数据,证实离子液体[EMIM][GAC]在一定条件下可消除乙腈和水混合物的共沸性。借助NRTL模型,获得了二元交互作用参数,关联温度和汽相组成绝对平均偏差分别为0.67 K和0.0078。基于Aspen Plus软件平台,建立了萃取精馏双塔流程,比较了萃取剂[EMIM][GAC]和乙二醇(EG)萃取精馏分离效果,结果表明[EMIM][GAC]作为萃取剂使溶剂物质的量比从0.94降至0.20、萃取精馏塔加热负荷降低9.4%,同时分离塔的理论级数从53降至20。
The azeotropic mixture of acetonitrile and water is always encountered in industrial engineering,and it is difficult to separate them using ordinary separation method,where some special separation technologies like extractive separation must be employed.Therefore,the vapor-liquid equilibrium(VLE)for the ternary mixture of acetonitrile+water+1-ethyl-3-methylimidazolium glycolate([EMIM][GAC])was firstly determined through experimental measurement and the ionic liquid of[EMIM][GAC]was verified to be effective in eliminating the azeotropy of acetonitrile and water mixture.Based on VLE data,the binary interaction parameters in NRTL model were then obtained with the overall average absolute deviations 0.67 K and 0.0078 for equilibrium temperature and vapor phase composition,respectively.Finally,the separation process with one extractive distillation column(EDC)and one solvent recovery column was built with Aspen Plus software.The simulation results showed that the IL entrainer of[EMIM][GAC]could decrease the molar solvent ratio from 0.94 to 0.20 and 9.4%for the heating duty of EDC,meanwhile the number of theoretical stage for EDC decreases from 53 to 20,comparing to ones of ethylene glycol entrainer.
作者
李进龙
石俸铭
李婷婷
疏其朋
LI Jinlong;SHI Fengming;LI Tingting;SHU Qipeng(School of Petrochemical Engineering,Changzhou University,Changzhou 213164,China;Sinopec Nanjing Engineering Co.,Ltd.,Nanjing 211100,China)
出处
《常州大学学报（自然科学版）》
CAS
2020年第1期14-21,共8页
Journal of Changzhou University：Natural Science Edition
基金
国家自然科学基金资助项目(21878025)
关键词
萃取精馏
离子液体
乙腈
水
共沸混合物
extractive distillation
ionic liquid
acetonitrile
water
azeotropic mixture
