A novel ternary mixed‐matrix membrane comprising Pebax‐1657, [HMIM][NTf₂] IL, and Al₂O₃ nanoparticles for efficient CO₂ separation

Abstract

An innovative technique to efficiently remove CO2 involves introducing a third component with a positive affinity with CO2 into a binary mixed‐matrix membrane (MMM) and eliminating interfacial defects in its structure. In this research, novel ternary MMMs (TMMMs) were synthesized by embedding 1–Hexyl–3–methylimidazolium bis(trifluoromethylsulfonyl)imide ([HMIM][NTf2]) ionic liquid (IL) and aluminum oxide (γ–Al2O3) nanoparticles into poly (ether‐block‐amide) (Pebax‐1657) matrix for enhancing CO2 removal from light gases. FESEM, DSC, ATR‐FTIR, and XRD analyses were used to evaluate the fabricated MMMs structurally. The permeation tests of gases (CH4, N2, and CO2) through prepared membranes were conducted at 25°C and 4, 6, 8, and 10 bar pressures. In accordance with the permeation outcomes, the ternary MMMs exhibited enhanced CO2 separation performances compared to the unloaded polymeric membrane. Also, the optimized MMM comprising 10 wt.% of the IL and 6 wt.% of the nanoparticles obtained a CO2 permeability of 173.90 Barrer, as well as CO2/N2 and CO2/CH4 selectivities of 77.98 and 24.29 at 10 bar and 25°C, which are higher by about 51%, 23%, and 22%, respectively than those of the pristine polymeric membrane. Based on these results, the prepared membrane appears to be a promising choice for separating CO2 from light gases.