变压精馏分离乙酸乙酯-正己烷共沸物的动态特性  

Dynamic Characteristics of Pressure-swing Distillation for Ethyl Acetate and n-Hexane Separation

作　　者：吕利平[1,2] 李航 李兵 孙诗瑞 张淑琼[1] 徐建华[1] LüLi-ping;LI Hang;LI Bing;SUN Shi-rui;ZHANG Shu-qiong;XU Jian-hua(Collaborative Innovation Center for Green Development in Wuling Mountain Area,Research Center for Environmental Monitoring and Hazard Prevention of Three Gorges Reservoir,School of Chemistry and Chemical Engineering,Yangtze Normal University,Chongqing 408100,China;School of Chemistry and Chemical Engineering,Southwest Petroleum University,Chengdu 610500,China;Sinochem Fuling Chongqing Chemical Industry Co.,Ltd.,Chongqing 408100,China)

机构地区：[1]长江师范学院化学化工学院,武陵山片区绿色发展协同创新中心,三峡库区环境监测与灾害防治工程研究中心,重庆408100 [2]西南石油大学化学化工学院,四川成都610500 [3]中化重庆涪陵化工有限公司,重庆408100

出　　处：《高校化学工程学报》2018年第2期478-486,共9页Journal of Chemical Engineering of Chinese Universities

基　　金：重庆市教委项目(KJ1712307),重庆市涪陵区科委项目(FLKJ,2016ABA1026);长江师范学院青年项目(2015XJXM03)。

摘　　要：乙酸乙酯和正己烷均为重要的有机溶剂,广泛应用于医药、橡胶、油漆等领域。由于乙酸乙酯和正己烷常压下形成共沸物,需采用特殊工艺对其进行分离。基于乙酸乙酯-正己烷二元共沸体系的压力敏感性,利用Aspen Plus软件,以年度总费用(TAC)最小为目标函数,模拟和优化了变压精馏稳态工艺,其中高压塔和低压塔的操作压力分别采用6 atm和1 atm,所得乙酸乙酯和正己烷产品纯度均大于99.9%。在此基础上,利用Aspen Dynamics软件考察了变压精馏工艺不同控制方案的有效性。结果表明:Q_R/F比例控制结构能够有效地应对进料流量扰动,且响应速度快,但在处理进料组分干扰时稍显不足。组分-温度串级控制能有效的改善进料组分扰动对产品纯度的影响。Q_R/F比例控制结构与组分-温度串级控制结构联用在变压精馏工艺中可实现稳健的控制,能够有效保证乙酸乙酯和正己烷产品纯度。Ethyl acetate and n-hexane as important organic solvents are widely used in medicine and other fields.Some special distillation methodsshould be considered to separate this system because of the presence of a minimum-boiling azeotrope.The design and simulation of pressure swing distillation are explored by Aspen Plus based on the pressure sensitivity of the azeotropic composition.The optimum conditions are obtained via taking the minimum total annual cost(TAC)as the objective function.The product purity of ethyl acetate and n-hexane is greater than 99.9%when the pressure of the high-pressure and lower-pressure columns is set at 6 and 1 atm respectively.To verify the industrial application of this process,the effectiveness of different control schemes is investigated by Aspen Dynamics.The results show that the QR/F ratio control scheme can effectively handle feed flow disturbance with fast response speeds.However,it is slightly less effective when handling feed component disturbance.The composition-temperature cascade control scheme can effectively improve the product purity influence of feed component disturbance.The QR/F ratio and composition-temperature cascade control scheme can achieve robust control and guarantee the product purity.

关 键 词：乙酸乙酯 正己烷 年度总费用 变压精馏 动态特性 

分 类 号：TQ208[化学工程—有机化工]