R-410A is a near-azeotropic refrigerant mixture of difluoromethane (HFC-32) and pentafluoroethane (HFC-125) that is scheduled to be phased out internationally due to a high Global Warming Potential (GWP). While conventional distillation cannot be used, extractive distillation using ionic liquids (ILs) has been proposed to separate and recycle HFC-32 (lower GWP) for future refrigerant blends and to repurpose HFC-125 (high GWP). Here, we present both a thermodynamic and process design analyses of various ILs using an equation of state method. From experimental binary vapor–liquid equilibrium data and equation of state modeling, 1-ethyl-3-methylimidazolium tricyanomethanide [C₂C₁im][tcm] and 1-ethyl-3-methylimidazolium dicyanamide [C₂C₁im][dca] were identified from 10 ILs as viable entrainers. Selectivity increases with temperature and decreases with pressure, while the solvent-to-feed (S/F) ratio did not have much effect. These effects were more pronounced for [C₂C₁im][tcm] than for [C₂C₁im][dca]. A sensitivity analysis reveals that the optimum operational parameters were solvent-to-feed ratio (S/F), reflux ratio (RR), and total number of stages (Nt) with values of 5, 3, and 20, respectively, for the case of [C₂C₁im][tcm] and 6, 3, and 20 for [C₂C₁im][dca]. High-purity products HFC-32 and HFC-125 (>99.5 wt %) were obtained with IL [C₂C₁im][tcm], providing the lowest energy consumption, compared to [C₂C₁im][dca] and other ILs.

中文翻译：

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使用咪唑氰离子液体分离制冷剂 R-410A 的萃取蒸馏的热力学和过程分析


R-410A 是二氟甲烷 （HFC-32） 和五氟乙烷 （HFC-125） 的近共沸制冷剂混合物，由于全球变暖潜能值 （GWP） 高，计划在国际上逐步淘汰。虽然不能使用常规蒸馏法，但已经提出了使用离子液体 （IL） 的萃取蒸馏法，以分离和回收 HFC-32（较低的 GWP）用于未来的制冷剂混合物，并重新利用 HFC-125（高 GWP）。在这里，我们使用状态方程法对各种 IL 进行了热力学和过程设计分析。从实验二元气液平衡数据和状态方程建模中，从 10 种 IL 中鉴定出 1-乙基-3-甲基咪唑鎓三氰化物 [C₂C₁im][tcm] 和 1-乙基-3-甲基咪唑鎓二氰胺 [C₂C₁im][dca] 为活的夹带剂。选择性随温度升高而降低，而溶剂与进料 （S/F） 的比率影响不大。[C₂C₁im][tcm] 的这些影响比 [C₂C₁im][dca] 更明显。敏感性分析显示，最佳操作参数为溶剂进料比 （S/F）、回流比 （RR） 和总级数 （Nt），对于 [C₂C₁im][tcm] 和 6、3 和 20，对于 [C₂C₁im][dca]。与 [C₂C₁im][dca] 和其他 IL 相比，IL [C₂C₁im][tcm] 获得了高纯度产品 HFC-32 和 HFC-125 （>99.5 wt %），提供了最低的能耗。