Abstract: The transport performances of carbon dioxide and methane were studied in polyethersulfone, polyethersulfone/ polyeterurethane (PES-ETPU) and polyethersulfone/polyestherurethane (PES-ESPU) blend membranes separately with different compositions. The variations in the structural characteristics of PES membrane after incorporation of ESPU and ETPU were investigated by different techniques. Additionally, the effect of pressure and composition on the permeance of CO₂, CH₄ and ideal selectivity of CO₂/CH₄ were checked on the membranes. The results revealed that themorphology of the blendmembraneswas affected by two opposite factors: thermodynamic enhancement and kinetic hindrance. The membranes with denser sponge layers were formed at lower ratio of PU/PES,whilemore porous structure with enlarged macrovoids membraneswere observed at higher PU content. The results indicated that adding PU to PES membrane, caused permeance improvement of the gases with nearly no change and/or reduction in ideal selectivity of CO₂/CH₄.Moreover, PES-ETPU membranes showed higher permeability and less CO₂/CH₄ selectivity in comparison with PES-ESPU samples. For PES-ESPU membrane containing 1.5% ESPU, CO₂ permeance at 10 bar was improved up to 20% with almost no change in CO₂/CH₄ selectivity with respect to PES. Finally, response surface methodology was used to evaluate the effects of the operating parameters on the permeance and ideal selectivity.

Key words: Absorption, Membranes, Size distribution, RSM, Polyethersulfone, Polyurethane

摘要： The transport performances of carbon dioxide and methane were studied in polyethersulfone, polyethersulfone/ polyeterurethane (PES-ETPU) and polyethersulfone/polyestherurethane (PES-ESPU) blend membranes separately with different compositions. The variations in the structural characteristics of PES membrane after incorporation of ESPU and ETPU were investigated by different techniques. Additionally, the effect of pressure and composition on the permeance of CO₂, CH₄ and ideal selectivity of CO₂/CH₄ were checked on the membranes. The results revealed that themorphology of the blendmembraneswas affected by two opposite factors: thermodynamic enhancement and kinetic hindrance. The membranes with denser sponge layers were formed at lower ratio of PU/PES,whilemore porous structure with enlarged macrovoids membraneswere observed at higher PU content. The results indicated that adding PU to PES membrane, caused permeance improvement of the gases with nearly no change and/or reduction in ideal selectivity of CO₂/CH₄.Moreover, PES-ETPU membranes showed higher permeability and less CO₂/CH₄ selectivity in comparison with PES-ESPU samples. For PES-ESPU membrane containing 1.5% ESPU, CO₂ permeance at 10 bar was improved up to 20% with almost no change in CO₂/CH₄ selectivity with respect to PES. Finally, response surface methodology was used to evaluate the effects of the operating parameters on the permeance and ideal selectivity.

关键词: Absorption, Membranes, Size distribution, RSM, Polyethersulfone, Polyurethane