带组分循环反应精馏合成丙酸正丙酯过程优化设计与控制

Optimal design and control of reactive distillation process with component recycle for the synthesis of n-propyl propionate

针对反应体系存在最不利挥发度序列的反应精馏难操作问题,提出带组分循环的反应精馏工艺,以过量正丙醇与丙酸酯化反应生产丙酸正丙酯为对象,构建了一种正丙醇循环的反应精馏工艺。通过热力学分析确定丙酸正丙酯和正丙醇二元体系存在夹点,系统研究了正丙醇循环纯度(X_(ProOH))对反应精馏集成过程的影响,并以年度总成本(TAC)为优化目标,通过序贯优化法确定反应精馏塔及回收塔的操作参数和结构参数。结果表明,当X_(ProOH)=0.80时,达到反应精馏塔反应过程和回收塔分离过程之间的权衡,获得TAC最小的工艺过程参数。此外,进一步提出一种组成/温度-比例控制方案,研究了闭环系统中引入±10%丙酸进料流量扰动时动态响应性能,结果表明该控制方案具有较好的抗干扰能力。

A reactive distillation process with component recycling is proposed to address the challenging operational issues for unfavorable volatility sequence in the reaction system.Taking the esterification of excess npropanol with propionic acid to produce n-propyl propionate as an example,a reactive distillation process with npropanol circulation was constructed.The pinch point of the binary vapor-liquid equilibrium of n-propyl propiate and n-propanol was determined by thermodynamic analysis,and the integrated process of reactive distillation was systematically studied to determine the purity of recycled n-propanol(X_(ProOH)).Using sequential optimization method,the operating parameters and structural parameters of the reactive distillation column and recovery column were determined with the minimum annual total cost(TAC)as the optimization objective.The results show that when X_(ProOH)=0.80,a trade-off between the reaction process of the reactive distillation tower and the separation process of the recovery tower is achieved,and the process parameters with minimum TAC are obtained.In addition,a composition/temperature-proportional control scheme is proposed to study the dynamic response performance of the closed-loop system when the disturbance of±10%propionic acid feed flow is introduced.