Abstract:

Acetone and n-heptane are frequently utilized solvents in the chemical industry and are commonly found in industrial wastewater. In this paper, 1-chlorobutane was used as an intermediate boiling point entrainer to separate acetone/n-heptane azeotropes using a sidestream extractive distillation (SSED) process and an extractive distillation with internally circulated (ICED) process, respectively. The two processes were optimized using a multi-objective genetic algorithm with total annual cost, CO₂ emission, and thermodynamic efficiency as evaluation indices, and the optimal equipment parameters and operating parameters were obtained. The optimization results indicated that the ICED process was more cost-effective, environmentally friendly, and thermodynamically efficient than the SSED process. In addition, the dynamic characteristics of the separation of acetone/n-heptane azeotropes using both methods were investigated. The dynamic characteristics of the separation of acetone/n-heptane azeotropes using both the SSED and ICED were investigated, and a reasonable control scheme was designed. After introducing disturbances in feed flow and feed composition, the products of both processes could be recovered close to the set values. The control effects of both processes were quantified using absolute deviation integrals, and the results showed that the ICED had better dynamic controllability.

Key words: azeotrope, extractive distillation, optimization, process control

摘要：

以1-氯丁烷为中间沸点夹带剂，分别使用侧线萃取精馏流程和内循环萃取精馏流程分离了丙酮-正庚烷共沸物。以年总费用、二氧化碳排放量和热力学效率为评价指标，使用多目标遗传算法分别对两流程进行了优化，获取了最佳设备参数与操作参数。优化结果表明，与侧线萃取精馏流程相比，内循环萃取精馏流程降低了9.77%的年总费用，11.95%的二氧化碳排放量，提高了1.47%的热力学效率。对侧线萃取精馏和内循环萃取精馏分离丙酮-正庚烷共沸物的动态特性进行了研究，构建了合理的控制方案。添加进料流量扰动和进料组成扰动后，两流程的产品均可恢复至设定值附近。使用绝对偏差积分对两流程的控制效果进行了量化，结果显示内循环萃取精馏流程具有更好的动态可控性。

关键词: 共沸物, 萃取精馏, 优化, 过程控制