CBE Seminar: W.S. Winston Ho

“New Amine-Based Membranes for H₂ Purification and CO₂ Capture”

This presentation covers new advances in amine-containing membranes for hydrogen purification for fuel cells and CO₂ capture from flue gas in coal- and/or natural gas-fired power plants and from <1% CO₂ concentration sources, e.g., the residual flue gas after the primary CO₂ capture system and coal-mine gas streams.  We have synthesized highly CO₂-selective membranes comprising fixed-site and mobile carriers, involving the facilitated transport mechanism based on reversible CO₂ reactions with amine carriers.  The membranes remove H₂S even faster than CO₂ (~3 times).  In general, the membranes need to be tailor-made and tuned specifically for those applications.  For example, hydrogen purification for fuel cells demands the membrane with a very high CO₂/H₂ selectivity of 100 along with a modest CO₂ permeance of about 100 GPU (1 GPU = 10^-6 cm³ (STP)/(cm² · s · cmHg)) or greater.  On the other hand, post-combustion carbon capture requires a high CO₂/N₂ selectivity of 140 together with a very high CO₂ permeance of greater than 700 GPU in order to use a stand-alone membrane process.  In order to achieve the membrane performance, highlighted are composite membranes comprising a high-selectivity layer on a highly permeable polymeric or inorganic/polymer support; the latter with zeolite nanoparticles can be used as the seed layer for continuous roll-to-roll fabrication of zeolite membranes.  Also highlighted are the effects of amine steric hindrance, CO₂ concentration and SO₂ on membrane performance as well as the scale-up of the membranes through continuous roll-to-roll fabrication and spiral-wound membrane module testing with simulated and actual flue gas streams.

Seminar Flyer_W.S. Winston Ho