萃取精馏分离醋酸乙烯-甲醇的计算机模拟及工业应用

Computer simulation and industrial application of the extractive distillation of vinyl acetate-methanol azeotropes

利用化工模拟软件Aspen Plus 7.3对萃取精馏分离醋酸乙烯-甲醇共沸物流程进行模拟和优化,对塔板数、回流比、进料位置、萃取剂流率和温度等操作参数进行灵敏度分析。模拟优化得到萃取精馏塔的设计参数为:塔板数31,回流比0.27,萃取剂进料位置第2块塔板,萃取剂流率21932 kg/h,混合物进料位置第22块塔板,塔顶采出量18477 kg/h。溶剂回收塔的设计参数为:塔板数24,回流比1.80,进料位置第19块塔板,塔顶采出量12626 kg/h。在此基础上,对优化前后能耗进行对比,节省循环水、蒸汽和萃取剂用量分别为285.9万t/a、3.2万t/a和4.4万t/a,每年共带来经济效益458.8万元。

Simulation and optimization of the extractive distillation of vinyl acetate-methanol azeotropes have been studied using Aspen Plus 7.3. The plate number, reflux ratio and feed position, and the extraction solvent flow rate and temperature have been analyzed using the tool of sensitivity analysis in Aspen. The optimized design parameters of the extraction column are as follows ： plate number 31, reflux ratio 0.27, extraction agent feeding position 2, extraction solvent flow rate 21932 kg/h, mixture feed position 22 and overhead recovery 18477 kg/h. The solvent re- covery tower design parameters are as follows： plate number 24, reflux ratio 1.80, feed position 19 and overhead recovery 12626 kg/h. The energy consumption becomes lower after the optimization of the distillation tower and re- covery tower. The amounts of water, steam, and extraction solvent saved by optimization are 2. 859 million t/a, 32000 t/a, and 44000 t/a, respectively, which lead to economic benefits of 4. 588 million yuan for every year of operation.