醋酸脱水非均相共沸精馏过程多稳态研究  

Study on multiple steady state in acetic acid dehydration system via heterogeneous azeotropic

作　　者：黄定伟[1] 李绍军[1] 

机构地区：[1]华东理工大学自动化研究所,上海200237

出　　处：《计算机与应用化学》2010年第10期1395-1398,共4页Computers and Applied Chemistry

基　　金：国家自然科学基金资助(20976048).

摘　　要：非均相共沸精馏过程中存在多稳态现象,它给共沸精馏过程的分析和控制带来了困难。本文利用流程模拟软件Aspen Plus对以醋酸正丁酯为共沸剂的醋酸脱水共沸精馏过程进行模拟计算。在稳态模型基础上,选择酯相进料流量为操作变量,塔底出料中醋酸含量为观察变量,对醋酸脱水系统进行灵敏度分析。分析结果表明,系统中存在多稳态区域,不同稳态下系统的行为特征相差较大。对开环系统进行动态脉冲测试表明,系统在酯相进料流量正脉冲作用下会从正常工作的稳态变化到低稳态,而通过控制精馏塔内温度变化区间的位置能够保证系统运行在所需的稳态上。最后,针对非均相共沸精馏过程模拟计算很难收敛到所需稳态的问题,本文分析指出可以通过酯进料流量的调节使模型计算收敛到所需的稳态。本文的多稳态研究方法较容易扩展到其它的非均相共沸精馏体系,研究结果将为实际共沸精馏过程的分析设计提供参考。The phenomenon of multiple steady states existed in the heterogeneous azeotropic distillation process,and it made the analysis and control of azeotropic distillation column to be difficult.In this paper,the acetic acid dehydration azeotropic distillation column in which n-butyl acetate was used as solvent was simulated by using Aspen Plus software.Base on the established steady-state model,the sensitivity analysis was carried out when the organic feed stream was selected as operating variable and the mess fraction of acetic acid in bottom was selected as observation variable.From simulation and analysis,the phenomenon of multiple steady states was observed in this system,the performances of the azeotropic distillation column were quite different under different steady states.The result of pulse testing which was carried out in dynamic simulation showed that the open-loop system was unstable,and it would change from the normal steady state to a low steady state during the positive pulse test.However,the normal steady state could be controlled by controlling the temperature changing front.Finally,a method was proposed to make sure the requied steady state acihved by operatiing the organic feed steam.The method used in this paper to study the muliple steady states was easily extended to other hetergeneous mixtures,and the result obeained would be helpful to anlysis and desigen hetergeneous azeotropic distillation system.

关 键 词：非均相共沸精馏 醋酸脱水 多稳态 脉冲测试 

分 类 号：TQ015.9[化学工程] TP391.9[自动化与计算机技术—计算机应用技术]