Development of Polycarbonate Ionic Liquid Mixed Matrix Membrane

The monetization of natural gas (NG) having high carbon dioxide (CO2) at more than 20% of the content currently facing challenges due to technology gap. The widely used technology, amine absorption can tolerate up to 10% of CO2 in NG. In idea of filling the gap, blend of polycarbonate (PC)MMMs and EMIMIm were prepared at different loading for CO2/CH4 separation. Each membrane was fabricated and dried under solvent evaporation at room temperature. Poor polymer-filler contact MMMs forming structure was observed using FESEM and improved polymer-filler in ILMMMs contact indicating ionic liquid miscibility and function in the membrane. TGA analysis showed all membrane contains minimal solvent at less than 1% suggesting the drying was efficient. All membranes were tested using single gas CO2 and CH4. Result showed that ILMMMs had 3 times higher selectivity than MMMs at 4 bar and 7 times better reduction of CH4 permeance. The effect of plasticization was also observed in all membranes while separation index is moderate the permeance is considered low. The preliminary results have shown improved polymer-filler contact using EMIMIm and technically improved the separation performance by restricting permeation of CH4 through void in the membrane matrix. The potent membrane sample is IL5MM5 which is dense, stable selectivity and permeation at increasing pressure.