基于NSGA-II的醋酸甲酯水解工艺经济优化控制

Optimization and Control of Hydrolysis Process of Methyl Acetate Based on NSGA-II

针对PTA生产系统中副产物醋酸甲酯水解工艺,研究基于最小经济成本的集成优化与厂级动态控制。首先根据醋酸甲酯水解工艺动力学机理模型,建立Aspen稳态模拟系统,采用灵敏度分析计算待优化变量的可行域,建立经济优化总成本目标函数;然后将模型计算和过程模拟相结合,利用NSGA-II算法寻找较优的反应精馏塔各操作参数,实现最小经济成本;最后依据最优的经济优化结构和操作参数,设计厂级动态控制系统,施加醋酸甲酯进料与流量扰动,其动态响应的结果验证了上述控制方案可以有效抑制扰动下的塔内各变量和产品成分变化,确保生产安全平稳运行。

For the methyl acetate hydrolysis process in the production system of PTA, the integration optimization and plant-level dynamic control based on the minimum economic cost were studied. Firstly, according to the kinetic mechanism model of the methyl acetate hydrolysis process, an Aspen steady-state simulation system was established.The sensitivity analysis was used to calculate the feasible region of the variable to be optimized. Then based on total annual cost(TAC) as the objective function, the NSGA-II algorithm was used to find the optimal operating parameters of the reactive distillation column to achieve the minimum economic cost. Finally, according to the optimal economic optimization structure and operating parameters, the plant-level dynamic control system was designed. The disturbance of the methyl acetate feed and the flow rate was applied. The results of its dynamic response verified that the control scheme could effectively suppress the variables and product composition changes in the column under the disturbance, and can ensure safe and stable production.