Facilitated Transport in Hydroxide‐Exchange Membranes for Post‐Combustion CO2 Separation. Issue 1 (20th September 2013) - Xiong, Laj
Abstract Hydroxide‐exchange membranes are developed for facilitated transport CO2 in post‐combustion flue‐gas feed. First, a correlation between the basicity of fixed‐site functional groups and CO2‐separation performance is discovered. This relationship is used to identify phosphonium as a promising candidate to achieve high CO2‐separation performance. Consequently, quaternary phosphonium‐based hydroxide‐exchange membranes are demonstrated to have a separation performance that is above the Robeson upper bound. Specifically, a CO2 permeability as high as 1090 Barrer and a CO2/N2 selectivity as high as 275 is achieved. The high performance observed in the membranes can be attributed to the quaternary phosphonium moiety.