(292g) Advanced Functionalized Polymeric Membranes for Molecularly Selective Gas Separations

Shouliang Yi^a, Ingo Pinnau^b, William J. Koros^a

^a School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311Ferst Drive, Atlanta, GA 30332, United States

^b Advanced Membranes and Porous Materials Center, Physical Sciences and Engineering Division,

King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia

Membrane-based gas separations have attracted significantly increasing attention in many environmental and energy processes such as natural gas purification, CO₂ capture, biogas upgrading, and hydrogen production during the last two decades, because of its inherent advantages including small footprint, low capital and operating costs, and lower energy requirements. The acid gases carbon dioxide (CO₂) and hydrogen sulfide (H₂S) are among the most commonly found impurities in natural gas. These impurities can cause corrosion of natural gas pipelines and processing equipment, as such, must be removed from raw natural gas before its distribution to consumers or delivery to pipelines.

While many membrane materials have been developed for the separation of CO₂/CH₄ over the past several decades, only a few studies have focused on the development of materials for removal of overall sour gas components due to the high toxicity of H₂S. In this presentation, a number of advanced functionalized polymers, including silane-grafted industrial standard glassy polymer cellulose esters, crosslinkable polymers based on the glassy 6FDA-based copolyimide 6FDA-DAM:DABA (3:2), and hydroxyl-functionalized polyimides with intrinsic microporosity, have been developed for molecularly selective separations from sour natural gas feeds. Specifically, the permeation and separation properties of these functionalized membranes was tested with high concentrations of H₂S and CO₂ feeds as well as high feed pressures. Ternary mixed gas (containing up to 20%H₂S) permeation results showed that these advanced membranes maintained excellent separation performance even under exceedingly challenging feed conditions. Our results indicate that these advanced materials have great potential in reducing the energy requirements and capital costs for environmentally friendly energy processes in industrial applications, which makes membrane-based gas separation technology an attractive option for clean energy production and reducing greenhouse gas emissions.