Research progress of polymer membrane separation materials in the field of natural gas desulfurization and decarbonization

Natural gas is a clean energy source, and its CO₂ emissions when burned are lower than those of other fossil fuels. Raw natural gas contains a certain amount of acidic gases such as CO₂ and H₂S, which must to be removed before entering the gas pipeline network. Membrane separation is a technology with a simple process and operation, which has a good application prospect in the field of natural gas desulfurization and decarbonization. The development of polymer membranes in the past 40 years, the separation mechanism and the application of membrane separation technology in the field of natural gas desulfurization and decarbonization were investigated. The types and applications of rubbery polymer membrane, glassy polymer membrane and hybrid membrane were summarized, and the application of membrane separation technology in the field of natural gas desulfurization and decarbonization was prospected. The rubbery polymer membrane has high permeability to H₂S but low H₂S/CH₄ selectivity. The glass polymer membrane has low permeability to H₂S but high H₂S/CH₄ selectivity. The hybrid membrane can balance permeability and selectivity by combining with functional nanomaterials, ionic liquids or deep eutectic solvent, which is the development trend of membrane separation materials in the future.