Economically and thermodynamically efficient heat pump-assisted side-stream pressure-swing distillation arrangement for separating a maximum-boiling azeotrope
Economically and thermodynamically efficient heat pump-assisted side-stream pressure-swing distillation arrangement for separating a maximum-boiling azeotrope
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DOI：
10.1016/j.applthermaleng.2020.115228
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发表时间：
2020-06
影响因子：
6.4
通讯作者：
Qingjun Zhang;Shunjin Yang;Peng Shi;Wei-xiao Hou;A. Zeng;Youguang Ma;Xigang Yuan
中科院分区：
文献类型：
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作者：
Qingjun Zhang;Shunjin Yang;Peng Shi;Wei-xiao Hou;A. Zeng;Youguang Ma;Xigang Yuan
以最大沸点乙二胺和水共沸物的分离为例，研究了两种热泵辅助侧流变压精馏装置(蒸汽再压缩和底部闪蒸热泵辅助系统)的可行性和有效性。为了进一步提高流程内的热回收，减少冷热设施的过度利用，采用了高效换热网络综合(HENS)分析工具。以年总成本(TAC)、碳足迹和热力效率为评价指标，对一系列变压精馏(PSD)工艺中的生态高效布置进行了评价和筛选。与部分热集成PSD流程相比，强化自热回热蒸汽再压缩辅助流程的能耗降低59.01%，CO2排放降低86.60%，TAC降低12.78%，热效率提高143.38%，是经济上最佳的流程。该工艺的热回收量为7028.0 kW，满足冷电395kW的要求，且不产生任何热电消耗(需用电)。此外，还分析了最优强化替代方案各组分的(火用)损耗率。结果表明，火用损失主要发生在塔内，尤其是高压塔。
The feasibility and effectiveness for the two types of heat pump-assisted side-stream pressure-swing distillation arrangements (vapor recompression and bottom flashing heat pump-assisted systems) are investigated with the separation of a maximum-boiling ethylenediamine and water azeotrope as the demonstrating example. To further improve the heat recovery within the process as much as possible and reduce the excessive utilization of cold and hot utilities, the efficient Heat Exchanger Network Synthesis (HENs) analysis tool is adopted. Total annual cost (TAC), carbon footprints and thermodynamic efficiency are as the evaluation indicators to assess and screen the eco-efficient arrangement in a series of pressure-swing distillation (PSD) processes. Compared to the partially heat-integrated PSD process, the economically optimum flowsheet is the intensified self-heat recuperative vapor recompression-assisted arrangement (VRC-SSPSD-PF-HEN) since it can achieve the reductions of 59.01% in energy consumption rates, 86.60% in CO2emissions, 12.78% in TAC and enhancement of 143.38% in thermodynamic efficiency. And the amount of heat recovery within this process is 7028.0 kW with the requirement of cold utility 395 kW andwithout anyhot utility consumptions (electrical power is required). Besides, the exergy destroyed in each component for the optimal intensified alternative is analyzed. Result shows that the major exergy losses mainly produce in columns, especially in high-pressure column.