Selective CO₂ separation from CO₂/C₂H₆ mixtures by immobilized diethanolamine/PEG membranes

CO₂ separation from a mixture of CO₂/C₂H₆ through membranes containing immobilized solutions of diethanolamine (DEA) and poly (ethylene glycol) (PEG) was carried out. The effects of flow pattern, flow rates, DEA concentration and CO₂ partial pressure were investigated. The addition of DEA in the membrane matrix resulted in the enhancement of CO₂ transport rate across the membrane. CO₂/C₂H₆ separation factors of up to 145 were obtained. Higher selectivities were obtained at lower CO₂ partial pressure differential conditions. An increasing CO₂ partial pressure differential across the membrane resulted in the saturation of the DEA carrier.