Pan Bin, Karadaghi Lanja R, Brutchey Richard L, Malmstadt Noah
Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, 925 Bloom Walk, Los Angeles, California 90089-1211, United States.
Department of Chemistry, University of Southern California, 840 Downey Way, Los Angeles, California 90089-0744, United States.
Ind Eng Chem Res. 2023 Dec 20;63(1):489-497. doi: 10.1021/acs.iecr.3c03312. eCollection 2024 Jan 10.
Recycling ionic liquid (IL) solvents can reduce the lifecycle cost of these expensive solvents. Liquid-liquid extraction is the most straightforward approach to purify IL solvents and is typically performed with an immiscible washing agent (e.g., water). Herein, we describe a recycling route for water-miscible ILs in which direct recycling is usually challenging. We use hydrophobic ILs as accommodating agents to draw the water-miscible IL from the aqueous washing stream. A biphasic slug flow of the mixed ILs and water is then separated by using a membrane. The water-miscible IL can then be drawn out from the mixed IL phase with acidified water and dried under vacuum. Both the water-miscible IL and the accommodating agent are then recycled. Here, we demonstrated a proof-of-concept of this process by recycling 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIM-OTf) in the presence of the accommodating agent 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIM-NTf) and acidified water. We then demonstrated the capacity to recycle 1-butyl-1-methylpyrrolidinium triflate (BMPYRR-OTf) from a realistic synthetic application: Pt nanoparticle synthesis in the water-miscible IL.
回收离子液体（IL）溶剂可以降低这些昂贵溶剂的生命周期成本。液液萃取是纯化IL溶剂最直接的方法，通常使用不混溶的洗涤剂（如水）进行。在此，我们描述了一种与水混溶的IL的回收路线，在这种路线中直接回收通常具有挑战性。我们使用疏水性IL作为容纳剂，从水洗流中提取与水混溶的IL。然后使用膜将混合IL和水的双相段塞流分离。然后可以用酸化水从混合IL相中抽出与水混溶的IL，并在真空下干燥。然后将与水混溶的IL和容纳剂都进行回收。在此，我们通过在容纳剂1-丁基-3-甲基咪唑双（三氟甲基磺酰）亚胺（BMIM-NTf）和酸化水存在下回收1-丁基-3-甲基咪唑三氟甲磺酸盐（BMIM-OTf），证明了该过程的概念验证。然后，我们展示了从实际合成应用中回收1-丁基-1-甲基吡咯烷三氟甲磺酸盐（BMPYRR-OTf）的能力：在与水混溶的IL中合成铂纳米颗粒。
