Ionic Liquid Stabilizes Olefin Facilitated Transport Membranes Against Reduction

Abstract

Separation of olefins from their paraffin analogs relies on energy‐intensive cryogenic distillation. Facilitated transport‐based membranes that reversibly and selectively bind olefins, but not paraffins, could save considerable amounts of energy. However, the chemical instability of the silver ion olefin‐binding carriers in such membranes has been a longstanding roadblock for this approach. We discovered long‐term carrier stability against extended exposure to hydrogen, a common contaminant in such streams. Based on UV/Vis absorption and Raman spectroscopy, along with XRD analysis results, certain ionic liquids solubilize silver ions, and anion aggregates surrounding the silver ion carriers greatly attenuate their reduction by hydrogen. Here, we report the stability of olefin/paraffin separation properties under continuous exposure to high pressure hydrogen, which addresses a critical technical roadblock in membrane‐based olefin/paraffin separation.

Hierarchical Yolk–Shell Porous Ionic Liquids with Lower Viscosity for Efficient C3H6/C3H8 Adsorption and Separation

“…Notably, the temperature dependence of the viscosity is correlated with the “Arrhenius” equations (Figure d, eq S1, and Table S4). Therefore, we conclude that the strong interactions in YSPILs1 between Z67@PDA and [C 2 OC 2 Im 2 ]­[TNf 2 ] require greater activation energy of viscosity ( E a,η ) to break interactions to facilitate flow. , Moreover, running YSPILs1 via a syringe with 5 mL, liquid droplets rapidly dripped off the needle within a few seconds, offering visual evidence of its fluidity (Figure S7). As expected, the low viscosity properties of YSPILs1 can effectively improve mass transfer and promote gas capture and separation.…”