Scientists from Singapore have investigated the effect of various salts on facilitated transport membranes for carbon dioxide (CO2) separation.
The addition of salts to polymeric membranes has proven to be a practical way to improve their permselectivity for gas separation. In this work, Rong Wang and Lizhi Zhang from the Nanyang Technical University looked into whether or not this could be applied to CO2separation. They found that with the addition of NaF salt, the permeance of N2 was significantly reduced (by a factor 9.4) – far more so than for CO2 (reduced by a factor of 1.5).
The authors also introduced polyoxometalates (POMs) as oxysalts into the membranes. Whilst the permeance of CO2through the membranes was much lower, the permselectivity of CO2 over N2was much greater. Due to their unique properties, POMs can be considered as attractive additives to membranes for CO2 separation.
Click on the link below to read this article for free!
Salting-out effect on facilitated transport membranes for CO2separation: From fluoride salt to polyoxometalates, Lizhi Zhang and Rong Wang, RSC Adv., 2012, DOI: 10.1039/C2RA20882B