摘要
采用萃取精馏技术对二氯甲烷和甲醇的共沸体系进行分离,以水为萃取剂,通过Aspen Plus软件对该过程进行工艺流程模拟,并利用灵敏度分析模块对萃取精馏塔的理论板数、进料位置、溶剂比、回流比和溶剂回收塔的理论板数、进料位置、回流比等参数对分离效果的影响进行了详细分析,确定了最优工艺参数为:萃取精馏塔理论板数为28,原料进料位置在第14块板,萃取剂进料位置在第4块板,溶剂比为0.6,回流比为1.6,塔顶产品二氯甲烷含量达到99.7%;溶剂回收塔理论塔板数为22,进料位置在第16块板,回流比为1.8,塔顶甲醇含量达到99.8%。在上述模拟优化的基础上进行了实验验证,实验结果与模拟结果相一致,验证了模拟结果的可靠性。最后,对某药厂年处理量为6 200 t的分离过程进行设计。
The azeotropic system of dichloromethane and methanol was separated by extractive distillation using water as extractive agent,which was simulated by Aspen Plus. The effect of extractive distillation tower's theoretical plate number,feed location,solvent ratio,reflux ratio and solvent recovery tower's theoretical plate number,feed location,reflux ratio were analyzed in detail by sensitivity analysis module. The optimal parameters were obtained as follows. Under the conditions of extractive distillation tower's theoretical plate number 28,mixture feed location 14,the water feed location 4,solvent ratio 0. 6,reflux ratio1. 6,and the purity of the product dichloromethane reaches 99. 7% at the top of tower. Under the conditions of solvent recovery tower's theoretical plate number 22,feed location 16,reflux ratio 1. 8,the purity of the product methanol reaches 99. 8% at the top of tower. Furthermore,experiments were carried out on the basis of the above simulation and optimization. The experimental results are in good agreement with the simulation results,and the reliability of the simulation results is verified. Finally,a separation process of 6 200 t per year in a pharmaceutical plant was designed.
引文
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