21 February 2019
Gas-separation membranes suitable for large industry
Published online 13 June 2013
Gas separation is an important step in power generation and petrochemical refinement. However, commercial gas-separation membranes are not sufficiently permeable for use in large-scale operations.
Now, an international research team from the University of Cambridge and Qatar University might have made such a membrane, reporting their results in a recent issue of Nature Communications1.
The membrane is made by modifying a new class of polymer materials known as polymers of intrinsic microporosity (PIMs) with ultraviolet (UV) irradiation in the presence of oxygen.
The UV irradiation formed a less porous skin layer at the surface of the newly prepared membrane. The skin layer has smaller holes while the remainder of the membrane is still highly porous, allowing small gas molecules to pass while blocking larger ones.
The modified membrane is much more permeable than existing commercial polymeric gas-separation membranes. And it is possible to control the porosity of the material, tailoring the new membrane for a variety of applications.
"These modified membranes can be used in air separation, hydrogen purification and recovery, removal of carbon dioxide from natural gas mixtures to produce purified methane, and carbon capture from combustion of fossil fuels," says Easan Sivaniah, the principal investigator of the study.
- Song, Q. et al. Photo-oxidative enhancement of polymeric molecular sieve membranes. Nat. Comm. (2013) doi:10.1038/ncomms2942