多效顺流精馏回收DMF的工艺

Technological Researches for Recovery of DMF by Multi-Effect Concurrent Distillation

针对传统的DMF回收工艺存在的高能耗问题,提出了多效顺流精馏回收DMF的双塔、3塔和4塔回收流程。利用ASPEN PLUS化工模拟软件中的RADFRAC模块,选用NRTL热力学计算模型,模拟计算了多效顺流精馏回收工艺处理不同DMF浓度的工况。以能耗最低为考察变量、各塔顶废水的蒸出量为决策变量,确定了各种回收工艺的最佳操作条件,包括各塔的压力分布。在此基础上,利用ASPEN软件中的流体力学计算模块,计算得到了各塔的设备参数,包括冷换设备的面积。以设备投资费用与操作费用之和最小为目标函数,确定了最优分离流程为3塔顺流精馏回收工艺。

Because of high energy consumption for separation of DMF, a multi--effect concurrent distil- lation which includes two--tower, three--tower and four--tower distillation was proposed. Simulation for different mass consistency DMF by multi--effect concurrent distillation was performed by ASPEN PLUS software in which RADFRAC blocks and NRTL physical property were used. The optimum operation conditions （including the press distributions） were determined based on minimum energy consumption and the variables of the top distillate, that is water vapor. Based on the results. The column parameters and areas of the condensers, heaters exchangers were calculated by hydromechanics blocks of ASPEN PLUS. The researches show that three--effect concurrent distillation is the best recovery methodology in response to the objective function of the least sum between cost of investment and operation cost.