(607c) New PSA Cycle for CO2 Removal during Closed-Loop Human Space Exploration Missions

The objective of this presentation is to provide modeling and/or experimental details about the development of a novel PSA cycle that can be used for enriching and recovering CO₂ from a spacecraft cabin that is suitable for use in a Sabatier reactor. This novel PSA cycle will utilize a combination of equalization, cocurrent depressurization and heavy reflux cycle steps to facilitate heavy component enrichment and recovery. Preliminary results obtained with the group’s dynamic adsorption process simulator (DAPS) revealed that a novel PSA cycle design utilizing 13X zeolite is indeed capable of enriching a dry gas stream of N₂ containing 3500 ppm of CO₂ to over 95 vol% CO₂ at high recovery with a similar removal rate to that of NASA’s current 5A zeolite system, which utilizes a temperature swing adsorption (TSA) cycle. Implications from these results potentially reach far beyond the needs of NASA and begin to hint at the extreme concentration of CO₂ from ambient air at relatively high recovery or the extreme concentration of any dilute species from a light gas stream using a simple PSA cycle. This presentation will discuss the most recent results obtained from DAPS and/or a multi-bed PSA system currently being modified for this unique application. This presentation will also discuss the most recent DAPS results obtained with a packed bed of commercial beaded adsorbent and/or a bed filled with a corrugated structured adsorbent that will facilitate higher mass transfer kinetics and lower flow resistance, thereby allowing for higher flow rates with significant bed size reduction.