热泵及热集成萃取精馏分离异丙醇-水的流程设计与比较

Process design and comparison of heat pump and heat integration extractive distillation for separating isopropanol-water

以乙二醇为萃取剂分离异丙醇和水的混合物。为降低能耗、节约成本和减少CO_(2)排放量,采用热泵和热集成技术强化萃取精馏过程。利用Aspen Plus软件,对常规萃取精馏、热泵萃取精馏和热集成-热泵萃取精馏等工艺进行了模拟和优化。从能耗、年度总费用(TAC)和CO_(2)排放量等方面对上述工艺进行了评价和比较。结果表明,在相同的设计基础和要求下,压缩机性能系数为10.19的热泵技术能显著降低能耗;与常规萃取精馏相比,热泵萃取精馏方案二节能效率为28%,可减少CO_(2)排放3.746×10^(6) kg/a,投资回收期为3 a时,TAC可节约0.72×10^(5) USD;充分利用循环萃取剂显热的热集成-热泵萃取精馏更具优势,节能效率达到了35%,可减少CO_(2)排放8.457×10^(6) kg/a,TAC降低了1.70×10^(5) USD,具有显著的环境效益和经济效益。

The mixture of isopropanol-water was separated with ethylene glycol as the extractant.With the goal of energy reduction,cost saving and CO_(2) emissions reduction,heat pump and heat integration technology were used to strengthen the extractive distillation process.Using Aspen Plus software,the conventional extractive distillation,the heat pump extractive distillation and the heat integrated-heat pump extractive distillation were simulated.The above processes were evaluated and compared from the energy consumption,total annual cost(TAC) and CO_(2) emissions.Under the same design basis and requirements,the results show that heat pump technology with compressor performance coefficient of 10.19 can significantly reduce energy consumption.Compared with the conventional extractive distillation,the heat pump extractive distillation scheme 2 can save energy by 28%,reduce CO_(2) emissions by 3.746×10^(6) kg/a and reduce TAC by 0.72×10^(5) USD when the payback period is 3 a.The heat integrated-heat pump extractive distillation which make full use of the sensible heat of circulating extractant has more advantages.It can save energy by 35%,reduce CO_(2) emissions by 8.457×10^(6) kg/a and reduce TAC by 1.70×10^(5) USD,has better environmental and economic benefits.