Effect of process parameters on power requirements of vacuum swing adsorption technology for CO2 capture from flue gas

This study focuses on the effects of process and operating parameters – feed gas temperature, evacuation pressure and feed concentration – on the performance of carbon dioxide vacuum swing adsorption (CO2VSA) processes for CO2 capture from gas, especially as it affects power consumption. To obtain reliable data on the VSA process, experimental work was conducted on a purposely built three bed CO2VSA pilot plant using commercial 13X zeolite. Both 6 step and 9 step cycles were used to determine the influences of temperature, evacuation pressure and feed concentration on process performance (recovery, purity, power and corresponding capture cost). A simple economic model for CO2 capture was developed and employed herein. Through experiments and analysis, it is found that the feed gas temperature, evacuation pressure and feed concentration have significant effects on power consumption and CO2 capture cost. Our data demonstrate that the CO2VSA process has good recovery (>70%), purity (>90%) and low power cost (4–10 kW/TPDc) when operating with 40 °C feed gas provided relatively deep vacuum is used. Enhanced performance is obtained when higher feed gas concentration is fed to the plant, as expected. Our data indicates large potential for application of CO2VSA to CO2 capture from flue gas.