Membrane separation of CO₂ from natural gas: A state-of-the-art review on material development

Natural gas (NG) processing and membrane technology are two very important fields that are of great significance due to increasing demand for energy as well as separation of gas mixtures. While NG is projected to be the number one primary source of energy by 2050, membrane separation is a commercially successful competitor to other separation techniques for energy efficient gas separation processes [1]. Most of the NG produced in the world is coproduced with acid gases such as CO₂ which need to be removed to increase the caloric value of NG. A comprehensive review of research efforts in CO ₂ separation from natural gas is required to capture details of the current scientific and technological progresses on the development of new membrane materials with better separation performance, and the improvement of properties of the existing ones. This paper presents the progress that has been achieved in eliminating the limitations that dominate the large scale application of membrane materials at the present time. Various polymers that have been developed to resist plasticization and the method employed to fabricate these polymers are highlighted. Also the range of plasticization pressures (together with corresponding selectivities and permeabilities at these pressures) that have so far been achieved by these fabrication methods is presented. It is believed that this review will serve as a good reference source especially for research in design and development of membrane materials with better resistance to CO₂-induced plasticization.