John Yang1,Yang Liu1
Aramco Research Ctr1
Natural gas plays a significant role in the global energy mix, and global natural gas demand has grown steadily in recent years. However, more than 40% of global natural gas reserves are highly sour, i.e. the percentage of CO<sub>2</sub> and H<sub>2</sub>S is significant. Their production and transport can be a challenge, due to its corrosiveness in the presence of water, leading to pipelines damages and H<sub>2</sub>S toxicity. Therefore, the produced natural gas must be treated and sweetened in order to meet the standard pipeline specifications for transport and processing. The bulk removal of H<sub>2</sub>S and CO<sub>2</sub> from natural gas remains an energy intensive separation challenge using the conventional amine absorption technology. Alternatively, membrane-based technologies have gained great industrial attention over the past decades due to their relatively energy-efficient and environment-friendly footprint. Designing novel structures and optimizing membrane performances for enhanced sour gas separations have been the subjects of intensive research in the Aramco Research Center-Boston during the past years. This talk will discuss the impact of polymer structures on the resulting permeation properties and high-pressure separation performance. Particular attention will focus on synthesizing novel glassy polymers (e.g. 6FDA-based co-polyimides), modifying rubbery polymers (e.g. poly(amide-<i>b</i>-ether) copolymers), and controlling their structures, which result in enhanced sour gas separation performance under industrially relevant feed streams and testing conditions (e.g. 20% H<sub>2</sub>S-containing sour gas feed at feed pressure up to 800 psi). These studies emphasize the observation that membrane separation performance is strongly related to chemical structure and the testing conditions, highlight the importance of exploring and designing better polymeric materials for the actual industrial gas process.