Abstract

This work considers four extractive distillation flowsheets of a benzene–cyclohexane–toluene mixture with different structures: one of them is conventional and consists of three two-outlet columns and three of them include schemes with thermally coupled distillation systems. For each flowsheet, the optimal steady state parameters with respect to the criterion of total reboiler heat duty are determined, automated control structures are developed, and the robustness against the external disturbances the form of variation of the flow rate and composition of the feed flow is analyzed. It is shown that the energy-consumption economy due to the application of thermally coupled distillation systems reaches 31.98%. An automated control structure is proposed for a system with a side stripping section, which reduces energy consumption by 28.37%. It provides comparable to conventional flowsheet control efficiency and robustness in the face of the disturbances.

中文翻译：

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苯-环己烷-甲苯混合物萃取蒸馏流程图的动态操作模式研究

摘要

这项工作考虑了具有不同结构的苯-环己烷-甲苯混合物的四个萃取蒸馏流程图：其中一个是传统的，由三个双出口塔组成，其中三个包括带有热耦合蒸馏系统的方案。对于每个流程图，确定了相对于总再沸器热负荷标准的最佳稳态参数，开发了自动控制结构，并且对外部干扰的鲁棒性（流量变化形式和进料流的组成）为分析了。结果表明，热耦合精馏系统的应用能耗经济性达到31.98%。提出了一种带有侧汽提段的系统的自动化控制结构，降低了28.37%的能耗。