(373aa) Elucidating Key Factors Dominating Natural Gas Sweetening Efficiency of Membranes

The world is in the middle of an energy transition period. Although renewable energy sources are expected to take an increasing share of the energy mix, natural gas, followed by oil, will still become the world’s primary energy source towards 2050. Indeed, natural gas can play a central role in supporting energy security alongside variable renewables during the transition. Moreover, combusting natural gas generates ~50% less carbon than burning an equivalent amount of coal. Natural gas production will continuously increase in the next 30 years; however, producing “clean” natural gas products is still expensive and energy-intensive by using thermally-driven amine absorption methods for treating undesirable acid impurities, e.g. hydrogen sulfide (H₂S) and carbon dioxide (CO₂). By now, roughly 40% of current global natural gas resources are contaminated with high concentrations of H₂S and CO₂, and H₂S concentrations in the Middle East can reach 30 mol.% along with significant amount of CO₂. Applying membrane methods can reduce the high cost, whereas it is still challenging to achieve high H₂S and CO₂ simultaneous removal efficiency using a single membrane device. This presentation will introduce our recent progress in membrane-based natural gas sweetening, i.e. (H₂S+CO₂) simultaneous removal. Specifically, we will discuss the key factors, e.g. feed gas composition, temperature, pressure, and gas sorption, diffusion, competition, polymer plasticization etc., that dominate the overall membrane separation performance. The findings being delivered in this presentation are important for guiding new membrane developments as well as evaluating existing membranes toward realistic applications.