Presented by Jennifer Wilcox - Department of Energy Resources Engineering, Stanford University
October 27, 2014
The scale by which CO2 must be mitigated worldwide dwarfs the existing chemical industry, making utilization of CO2 as a chemical feedstock a minor component of the portfolio of mitigation options. Carbon capture and storage is one strategy that could potentially mitigate gigatons of CO2 emissions per year, provided geological storage of CO2 is feasible. The scale and energy requirements associated with CO2 separation processes will be presented. Strategies based upon adsorption and catalytic membrane separation processes in particular, will be of focus. Regeneration of CO2 is known to be a significant component of sorption-based separation processes and is absent when using membrane technologies. Nitrogen-selective membranes will be introduced. In particular, metallic membrane materials for selective N2 separation for carbon capture will also be presented. This work involves the adsorption, dissociation, and sub-surface diffusion of N2 in Group V-based metals, including vanadium, niobium, and their alloys with ruthenium. The electronic structure of the metal can be tuned based upon alloying, thereby enhancing N2 permeability. Experimental N2 flux measurements have been carried out to validate the theoretical predictions.