Ingo Pinnau, Professor Chemical Engineering, King Abdullah University of Science and Technology (KAUST)
"Membrane-Based Gas Separation Technology: Applications, Materials & Membranes"
Abstract:
Membrane-Based Gas Separation Technology: Applications, Materials & Membranes Industrial membrane technology was introduced in the 1960s for seawater desalination by thedevelopment of integrally-skinned asymmetric cellulose actetate reverse osmosis (RO) membranes. However, it took about 20 years of further membrane optimization, module development and pilot-scale process demonstrations before this technology was accepted as a viable unit operation process for the production of potable water. In the mid 1970s, the first generation gas separation membranes were based on cellulose acetate (Dow Chemical, Toyobo, Separex) and polyaramide (Du Pont) RO membranes. Large-scale gas separation membrane plants were introduced by Monsanto in the early 1980s using multicomponent hollow fibers — the major innovation of their approach was to apply a thin (< 1 μm) silicone rubber sealing layer to plug defects in the ultrathin (< 0.2 μm) skin layer of asymmetric polysulfone fibers. This approach eliminated non-selective pore flow by Knudsen diffusion/bulk flow and transformed a defective membrane into a high-performance defect-free gas separation membrane in which permeation was solely determined by a solution/diffusion mechanism. Membrane-based gas separation technology started to blossom in the 1990s and early 2000s and was successfully applied to air separation, CO2 removal from natural gas and biogas, hydrogen recovery in ammonia and petrochemical plants and hydrocarbon recovery in polyolefin plants.
The selection of novel polymeric membrane materials is based on overcoming the reverse relationship of gas permeability and gas-pair selectivity, introduced by Robeson in 1991. Since then, hundreds of better performing polymers have been developed for various applications — however, even in 2026 most gas separation membranes are fabricated using commercially available polymers, such as polycarbonate, polysulfone, polyimide, polydimethylsiloxane etc. The bottleneck to transform materials into high-performance gas separation membranes results from a variety of causes other than their intrinsic gas transport properties: (i) materials cost, (ii) materials scale-up, (iii) large-scale production of membranes, (iv) unstable, long-term gas permeation properties due to physical aging, penetrant-induced plasticization, pore plugging etc.This presentation will identify important current limitations of membrane-based gas separations and provide future directions to further expand the technology. Specific emphasis will be placed on highly permeable polymers of intrinsic microporosity(PIMs) and ultra-selective
carbon molecular sieve (CMS) membranes.
Bio:
Ingo Pinnau is Professor of Chemical Engineering at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia. He served as Founding Director of the Advanced Membranes and Porous Materials Center from 2009-2017 and was Chemical Engineering Program Chair for 10 years. Dr. Pinnau received his Ph.D. in Chemical Engineering from the University of Texas at Austin in 1991. Prior to his appointment at KAUST he was Director of Materials and Membrane Development at Membrane Technology and Research, Inc. (MTR) for 18 years and served as Consulting Professor in the Environmental Engineering Department at Stanford University. Dr. Pinnau co-edited four books on membrane science and is the author of 230+ publications. He holds 54 granted U.S. patents, served twice as President of the North American Membrane Society (NAMS) and was elected NAMS Fellow in 2020. Prof. Pinnau is on the Editorial Board of the Journal of Membrane Science and Advanced Chemical Engineering. He holds various professional memberships and has received several national and international awards. His research activities focus on synthesis of advanced polymers and carbon molecular sieves, high-performance membranes and processes for energy-intensive gas-and liquid separations.