Abstract:

This paper focuses on the simulation, optimization and control of the reactive dividing wall column for the production of n-butyl acetate through ester exchange reaction. The optimal operating conditions are obtained with the minimum total annual cost(TAC) as the target function. Different matching relationships between manipulate variables and control variables are determined through the sensitive analysis of steady state relative gain and the Relative Gain Array(RGA) criterion, and then three control structures are built in Aspen Dynamics. It shows that the use of the reactant feed ratio to control the stage temperature is effective to handle the feed disturbances, which presents superior ability in maintaining stability of this system. At last, an improved control structure(CS3) is proposed, which deletes the ratio of reboiler duty and mixture feed rate and shows a great advantage in reducing overshoot of product purities. The specific control structure of CS3 is as follows: the reboiler load of reactive distillation column controls the temperature of the 16th plate of the reactive distillation column directly; ratio of feed rate for n-butanol and methyl acetate/methanol mixture controls the temperature of 28th plate of the reactive distillation column; and the reboiler load of stripping column controls that of the 3rd plate of stripping column directly.

Key words: reactive dividing wall column, transesterification, TAC, optimization, dynamic simulation, control

摘要：

对反应精馏隔壁塔生产乙酸正丁酯过程进行了模拟、优化与控制的系统研究。利用Aspen Plus软件模拟乙酸甲酯与正丁醇的酯交换反应过程，以年总费用（TAC）为目标函数进行过程优化，通过稳态敏感性分析及相对增益矩阵（RGA）判据得到不同的操纵变量与控制变量匹配关系，以此为基础，在Aspen Dynamics平台建立了若干控制结构并进行分析对比。结果表明，利用两股反应物呈比例进料可较为有效地抵抗进料扰动，最后提出的无再沸器热负荷与混合物进料量比值（Q_r/F）控制的改进控制结构CS3，在降低反应精馏隔壁塔控制过程超调量方面有较大的优越性。

关键词: 反应精馏隔壁塔, 酯交换反应, TAC, 优化, 动态仿真, 控制