Process Designs for Separating R-410A, R-404A, and R-407C Using Extractive Distillation and Ionic Liquid Entrainers
Process Designs for Separating R-410A, R-404A, and R-407C Using Extractive Distillation and Ionic Liquid Entrainers
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DOI：
10.1021/acs.iecr.1c02891
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发表时间：
2021-10
影响因子：
4.2
通讯作者：
Ethan A. Finberg;M. Shiflett
中科院分区：
文献类型：
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作者：
Ethan A. Finberg;M. Shiflett
氢氟碳化合物制冷剂由于其高的全球变暖潜力，将在未来二十年内逐步淘汰。为了分离和回收形成共沸混合物的制冷剂，目前的蒸馏方法是不够的，需要一种新的技术。使用离子液体作为萃取剂的萃取蒸馏提供了一种解决方案。制冷剂二氟甲烷（HFC-32）、一氯二氟甲烷（HCFC-22）、五氟乙烷（HFC-125）、1，1，1-三氟乙烷的气液平衡数据（HFC-143 a）和1，1，1，2-四氟乙烷（HFC-134 a）在离子液体中的1-乙基-3-甲基咪唑双三氟甲磺酰亚胺（[C2 C1 im][Tf 2N]）和1-丁基-3-甲基咪唑鎓六氟磷酸盐[C4 C1 im][PF 6]）与Peng-Robinson状态方程拟合，模拟了四种共沸混合制冷剂的分离（R-404 A、R-407 C、R-410 A和R-410 A + HCFC-22），并在白杨Plus中开发基于比率的平衡模型。根据一系列物理和化学约束条件，开发并优化了工艺流程图。目标是优化参数以实现制冷剂级（> 99.5wt%）纯度。离子液体被发现是有效的分离制冷剂混合物的澄清剂。
Hydrofluorocarbon refrigerants are being phased out over the next two decades due to their high global warming potential. To separate and recycle refrigerants that form azeotropic mixtures, current distillation methods are inadequate and a new technology is required. Extractive distillation using an ionic liquid as the entrainer offers a solution. Vapor liquid equilibria data for refrigerants difluoromethane (HFC-32), chlorodifluoromethane (HCFC-22), pentafluoroethane (HFC-125), 1,1,1-trifluoroethane (HFC-143a), and 1,1,1,2-tetrafluoroethane (HFC-134a) in ionic liquids 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2C1im][Tf2N]) and 1-butyl-3-methylimidazolium hexafluorophosphate ([C4C1im][PF6]) were fit with the Peng–Robinson equation of state to simulate the separation of four azeotropic refrigerant mixtures (R-404A, R-407C, R-410A, and R-410A + HCFC-22) and to develop rate-based and equilibrium models in ASPEN Plus. Process flow diagrams were developed and optimized based on a set of physical and chemical constraints. The goal was to optimize the parameters to achieve refrigerant grade (>99.5 wt %) purity. The ionic liquids were found to be effective entrainers for separating refrigerant mixtures.