Demonstration of Metabolic Heat Regenerated Temperature Swing Adsorption Technology

Patent-pending Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is currently being investigated for removal and rejection of carbon dioxide (CO₂) and heat from a Portable Life Support System (PLSS) to a Martian environment. The metabolically-produced CO₂ present in the ventilation loop gas is collected using a CO₂ selective adsorbent that has been cooled via a heat exchanger to near CO₂ sublimation temperatures (∼195 K) with liquid CO₂ (LCO₂) obtained from Martian resources. Once the adsorbent is fully loaded, used, warm (∼300 K), moist ventilation loop gas is used to heat the adsorbent via another heat exchanger to reject the collected CO₂ to the Martian ambient. Two beds are used to achieve continuous CO₂ removal by cycling between the cold and warm conditions for adsorbent loading and regeneration, respectively. A Demonstrator has been designed, built, and tested to investigate the feasibility of 1) warming the adsorbent using the ventilation loop, 2) cooling the adsorbent using LCO₂, and 3) using these two methods in conjunction to remove CO₂ from a simulated ventilation loop and reject it to simulated Mars ambient. Both analytical and numerical methods were used to perform design calculations and trades. The demonstrator was built and tested. The design analysis and testing results are presented along with recommendations for future development required to increase the maturity of the technology.