热泵精馏技术在芳烃分离工艺中的应用研究

Application of Heat Pump Distillation Technology on Aromatic Hydrocarbon Seperation Process

热泵精馏技术可以极大的节省分离过程中的能量消耗。本研究以芳烃分离工艺为研究对象,在原有分离工艺中采用热泵精馏技术回收甲苯塔顶气相热量,并将其作为苯塔塔底的热源,选用水作为循环工质,应用机械蒸汽再压缩式热泵(MVR),有效回收塔顶低温气相物流的冷凝潜热。通过能量平衡分析和分析,表明热泵循环的COP值约为25左右,所设计的热泵循环效率达到86%,通过压缩机消耗约265 kW的电能,可以有效提升甲苯塔顶气相低温热的能级,获取约6629 kW的高温位热量,用作苯塔塔底再沸器热源。该低温热泵循环的能量利用率约为97%,利用率约86%,能量回收利用较理想,同时可以极大减少原有甲苯塔顶气相的空冷水冷负荷,节能效果显著。

Heat pump distillation technology can greatly reduce energy consumption during the separation process.Focusing on the separation process of aromatic hydrocarbons,heat pump distillation technology was employed in the original separation process to recover the heat from the overhead vapor of the toluene column and utilize it as the heat source for the bottom of the benzene column.Water was selected as the circulating working fluid,and a Mechanical Vapor Recompression(MVR)heat pump was applied to effectively recover the condensation latent heat of the low-temperature gas-phase flow at the top of the column.Through energy balance analysis and exergy analysis,it was shown that COP value of the heat pump cycle was approximately 25,and the exergy efficiency of the designed heat pump cycle reached 86%.By consuming about 265 kW of electricity for compression,the low-temperature heat energy level of the overhead vapor of the toluene column can be effectively increased,obtaining about 6629 kW of high-temperature heat,which was used as the heat source for the reboiler at the bottom of the benzene column.The energy utilization efficiency of this low-temperature heat pump cycle was approximately 97%,and the exergy utilization efficiency was about 86%.The energy recovery and utilization are quite ideal,while significantly reducing the original toluene column s air-cooled water-cooling load,resulting in remarkable energy-saving effects.