Abstract: As an abundant resource,isobutane has relatively low industrial utilization and reuse. A conventional process was capable of separating isobutane from a mixture of this compound with C₃ and C₄;however,large energy consumption was needed due to high purity requirements.. The current treatment of distillation process is limited to optimizing process parameters,but the heat pump is rarely reported. To solve this problem,this research a designed and optimized the distillation procedure to minimize the energy consumption in the isobutene/n-butane separation. The simulated results of the process showed that the optimal energy-efficient was obtained at 7×10⁵Pa at the top and 7.5×10⁵Pa at the bottom,the circle working flow of 3055.13kmol/h and the compression ratio of 2.286. A thermodynamic analysis for the heat pump system was performed,and compared with conventional process. The results suggested that the new process was able to decrease the energy consumption from 68.16GJ/h to 45.87GJ/h. The proposed heat pump technology could be used as an energy-saving and green technology.

Key words: separation, optimal design, distillation, isobutane, heat pump distillation, energy saving

摘要： 异丁烷资源丰富,但工业利用率低,造成资源未得到合理利用。本文首先分析了C₃和C₄混合物分离体系的特点,建立异丁烷精馏常规工艺流程,并对其进行模拟计算。模拟结果表明:塔釜蒸汽消耗量较大,造成能耗过高。目前,解决精馏过程能耗过高的处理方式集中在工艺参数的优化,在精馏方式上却少有报道。为了解决这一问题,本文提出了采取热泵精馏技术进行节能改造,并建立了异丁烷精馏的热泵精馏新工艺。通过模拟计算且对结果进行深入分析,得出当塔顶/塔釜压力分别为7×10⁵Pa和7.5×10⁵Pa、循环工质流量3055.13kmol/h、压缩机压缩比为2.286条件下满足分离要求,且能耗较低。分析热力学效率与经济性并与常规流程进行对比,结果表明:热泵精馏新工艺节能效果极佳,由常规精馏的68.16GJ/h降低为热泵精馏的45.87GJ/h;热泵精馏新工艺适用于该体系且更加节能、环保。

关键词: 分离, 优化设计, 蒸馏, 异丁烷, 热泵精馏, 节能