The ability to selectively and efficiently separate CO2 from gas mixtures is of huge interest due to the prevalence of CO2 as an industrial byproduct and its global-warming potential. Compared to amine solutions, separation by room-temperature ionic liquids (RTILs) possess numerous advantages including negligible vapor pressures and low desorption energies. To understand the interaction of the surface of RTILs with CO2 at the molecular level, we characterize CO2 binding mechanisms using analytical methods including X-ray diffraction (small/wide-angle X-ray scattering), gravimetric/ thermogravimetric analysis, viscosity measurements, Raman spectroscopy, and Fourier transform infrared spectroscopy (in situ variations of pressure and temperature). Our collaborators from the University of California – Riverside are substantiating our results with theoretical calculations. We also investigate the flow of CO2/N2 mixture through RTILs and polymer membranes, using membrane test systems coupled with gas chromatography, to identify materials with high selectivity and fast diffusivity. Our work aims to produce future energy savings consistent with the mission of U.S. Department of Energy.
Jihang Wang, ’15
Sponsor: Craig Teague