变压精馏分离丙酸甲酯-甲醇的节能设计

基于丙酸甲酯-甲醇二元体系的压力敏感特性,以最小年总费用(TAC)作为经济评价指标,对变压精馏分离工艺进行了模拟与优化,并在常规工艺基础上进行了改造,以实现节能的目的。结果表明:常规分离工艺高压进料时,高压塔塔板数为41、回流比为1.5和进料位置为第33块板以及低压塔塔板数为39、回流比为2.0和进料位置为第17块板时TAC最低,为593.00万元/年。将热集成技术应用于常规工艺中,优化后的分离工艺均能实现物系的高效分离。相比于常规变压精馏,部分热集成变压精馏与全热集成变压精馏分别可以节约44.57%与41.94%的能耗,同时可以节约23.84%与32.59%的TAC,主要原因是热量集成使得蒸汽费用与换热器费用降低。优化后的两种工艺分离效果显著,且能耗与TAC均较低,可为工业设计提供理论参考。

Energy saving design for separation of methyl propionate-methanol by pressure swing distillation

Based on the pressure sensitive characteristics of the methyl propionate-methanol binary system,the process of pressure swing distillation was simulated and optimized with the minimum total annual cost(TAC)as the economic evaluation index,and the conventional pressure swing distillation process was modified to achieve the purpose of energy saving.The results show that when the conventional separation process is fed at high pressure,and the number of high pressure column trays is 41,the reflux ratio is 1.5 and the feed position is 33,and the number of low pressure column trays is 39,the reflux ratio is 2.0 and the feed position is 17,the TAC is the lowest,which is 593.00×10;yuan/a.When the heat integration technology is applied to the pressure swing distillation process,the optimized separation processes can realize the efficient separation of the system.Compared with the conventional pressure swing distillation,partial heat integrated pressure swing distillation and full heat integrated pressure swing distillation can save 44.57%and 41.94%energy consumption,and 23.84%and 32.59%TAC,respectively.The main reason is that the heat integration reduces steam costs and heat exchanger costs.The separation effects of the two optimized processes are significant,and the energy consumption and TAC are low,which can provide theoretical reference for industrial design.