(285g) Development of Advanced Polymer Membranes for CO2 and H2s Removal from Natural Gas

Natural gas is a crucial energy resources globally, and its demand has been on a steady rise in recent years. While it mainly consists of methane, raw natural gas also contains large amount of impurities, such as acid gases (carbon dioxide (CO₂), hydrogen sulfide (H₂S), nitrogen, heavy hydrocarbons etc.), and its composition varies depending on its origin. Currently, more than 40% of world’s available natural gas resources are sour, with H₂S concentration reaching up to 30mol% in some Middle Eastern countries. However, due to the corrosive and toxic nature of H₂S and CO₂, sour gas must undergo sweetening before use, which has been a long-standing need in the oil and gas industry, including Aramco. Unlike the traditional amine adsorption technology, gas-separating membrane systems have gained significantly industrial attention due to their high energy efficiency, small footprint, and low capital cost. At the Aramco Research Center – Boston, intensive research has been carried out to design novel membrane structures and optimize their performances for CO₂ and H₂S removal from natural gas under harsh conditions. This presentation focuses on recent progress in the simultaneous removal of (H₂S + CO₂) from highly sour natural gas. We will discuss the impact of polymer structures on high-pressure permeation properties and pay particular attention to synthesizing novel glassy polymers (e.g., 6FDA-based polyimides), modifying rubbery polymers (e.g., Pebax, PEG etc.), and controlling the structures. These efforts result in enhanced sour gas separation performance under realistic gas processing conditions. Our work suggests a new direction for the design of advanced membrane materials toward actual industrial gas processing.