(646c) CO2 Facilitated Transport Membranes

Tong, Z., The Ohio State University
Ho, W., The Ohio State University
Membrane separation is a promising technology for CO2 separation and capture because of the high energy efficiency, small footprint and operational simplicity. CO2 facilitated transport membrane is an important group of membranes for CO2 separation. This work first reviews the state of the art in CO2facilitated transport membranes, followed by some current results on novel amine-containing membranes.

In this work, the facilitated transport mechanism is described in conjunction with the chemical reactions of CO2and amine carriers. A wide range of facilitated transport membranes is discussed, including amine-based fixed-site carrier membranes, amine mobile carrier-containing membranes, and other facilitated transport membranes with different types of carriers and/or inorganic fillers to further improve the performance of facilitated transport membranes.

High molecular weight polyvinylamine was successfully synthesized in our group, which served as the fixed site carrier and the polymer matrix to incorporate mobile carriers into the membranes. The membranes demonstrated a CO2 permeance of 757 GPU and a CO2/N2 selectivity of 151 under the typical conditions for flue gas CO2 capture (57 °C, 1 atm, 100% relative humidity, 20% CO2 in the feed gas balanced with N2 on a dry basis). As reported that the CO2 loading capacity of sterically hindered amine can be twice of unhindered amine in aqueous solution, the high molecular weight polyvinylamine was also modified into sterically hindered polyvinylamine in this work and demonstrated up to 24% improvement in CO2 permeability and 14% increase in CO2/N2 selectivity. Sterically hindered polyvinylamine has the potential to become the next-generation fixed site carriers for CO2 facilitated transport membranes.