基于MVR热泵和热集成的混合二甲苯节能精馏工艺

Energy saving distillation process for mixed xylene system based on MVR heat pump and heat integration

针对混合二甲苯体系分离能耗高的特点,把热集成和MVR热泵技术应用于该体系的分离研究,提出了热集成精馏工艺、带预分的MVR精馏工艺和完全MVR热泵精馏工艺。以能耗和年总费用(TAC)作为评价指标,对以上提出的3种节能精馏工艺进行模拟与优化,并与常规精馏工艺的计算结果进行了比较与分析。研究结果表明,热集成精馏工艺要比常规精馏工艺具有一定的经济优势,平均可减少能耗34.44%,节省TAC 23.33%。而MVR热泵精馏工艺则是分离该体系的最合适的工艺路线,与热集成精馏工艺相比,带预分的热集成MVR精馏工艺和完全MVR热泵精馏工艺可分别减少能耗23.23%和64.45%;节省TAC 18.32%和21.68%。

According to the characteristic of high energy consumption for separation of mixed xylene system,heat integration and MVR heat pump technology are applied. The heat-integrated distillation process,MVR rectification process with pre-fractionation and the complete MVR heat pump distillation process are proposed for separation of mixed xylene system. The energy saving and annual total cost（TAC） are used as the evaluation indexes to simulate and optimize the three energy-saving distillation processes,using conventional rectification process as control. The results show that the heat integrated distillation process has certain economic advantages compared with the conventional distillation process,which can save 34. 44% of energy and 23. 33% of TAC. The MVR heat pump distillation process is the most suitable process for separation of the mixed xylene system. The MVR rectification process with pre-fractionation and the complete MVR heat pump distillation process can save 23. 23% and 64. 45% of energy,18. 32% and 21. 68%of TAC,respectively,compared with the heat integrated distillation process.