A favored CO2 separation over light gases using mixed matrix membrane comprising polysulfone/polyethylene glycol and graphene hydroxyl nanoparticles

Abstract

A novel polysulfone (PSF) mixed matrix membrane blended by polyethylene glycol (5 and 10wt.%) was synthesized in which the graphene hydroxyl (G-OH) nanoparticles incorporated. Polyethelene glycol (PEG) as an affordable additive provides a proper CO2 affinity. Moreover, the G-OH nanoparticles was enhanced the CO2 permeability in MMMs through Lewis acid- base interaction between electron withdrawing oxygen of −OH and CO2. First, PSF membrane was modified via adding PEG. Obtained results were shown that the CO2 permeability increased significantly from 15.9 Barrer (for neat PSF) to 28.2 Barrer (for PSF/PEG (10wt%), while a fairly significant increase in CO2/CH4 selectivity (from 12.23 for neat PSF to 12.81 for PSF/PEG (10wt%) at the pressure of 2bar and temperature of 35°C. Second, the G-OH nanoparticles were incorporated (1, 2, 3, 4 and 5wt%) into the both PSF/PEG (5wt%) and PSF/PEG (10wt%) matrix to prepare the PSF/PEG/G-OH MMMs. Results showed the best CO2/CH4 selectivity was obtained at 5wt% loading of G-OH for both PSF/PEG (5wt%) and PSF/PEG (10wt%) were 20.94 and 22.39, respectively; at pressure of 8bar. The separation properties of membranes were also evaluated at higher feed pressure and the obtained results were discussed.