REZA HAGHPANAH | Stanford University
"Post-combustion CO2 Capture by Adsorption Processes"
Adsorption technology has been widely studied as a candidate for post-combustion CO2 capture from natural gas and coal-fired power plants. Conventional adsorption processes have been designed and optimized for the purification of the light gas. However, in carbon capture applications, the challenge is to recover the heavier product, CO2, in high purity. This requires novel cycles that incorporate different steps for extract enrichment. In addition to the cycle design, the choice of the adsorbent for CO2capture is critical factor. Based on adsorption selectivity and working capacity, researchers have argued the superiority of one material over the other. Although these are both important characteristics and show strong correspondence to process performance, one needs to couple full process modeling and optimization with material properties, i.e., equilibrium and kinetic data. This important test is often missing in the literature and can help create more focused research and development into carbon capture process.
This work presents the systematic analysis of vacuum swing adsorption (VSA) and pressure-vacuum swing adsorption (PVSA) cycles with zeolite 13X and carbon molecular sieve, both of which are commercially available for necessary wide scale deployment, as the adsorbent to capture CO2from dry, post-combustion flue gas containing 15% CO2in N2. The analyzed VSA/PVSA cycles have been fully optimized to obtain purity-recovery and energy consumption-productivity Pareto curves. The Pareto curves highlight the cycles that may be viable for industrial scale post-combustion carbon capture.