High Capacity RCA Sorbents for Increased Cycle Times

NASA is interested in improving the method to control CO2 and water in the Exploration Extravehicular Mobility Unit (xEMU) to meet the ambitious objectives of the Artemis program, which includes human presence on the surface of the Moon and Mars. These levels must be controlled to established values of 2.2 mm Hg at a metabolic rate of 2.44 g/min. Historically, the Metox has been used to remove CO2 from the suit. The sorbent in the Metox has a finite capacity during an EVA and must be regenerated after the mission is complete. The capacity limits mission times, which can only be increased by making the Metox larger. The technology that is planned to replace the Metox is the RCA which utilizes two beds that are alternately used to remove CO2 and H2O and then regenerated by exposure to space vacuum. The RCA has been under development for over 10 years and has utilized an amine-based sorbent (SA9T). Although SA9T has good reversible CO2 uptakes, higher capacities are desired to maintain low CO2 levels and reduce O2 losses. In addition, this sorbent emits low levels of ammonia which must be removed from the suit using a separate technology.In this SBIR Phase I project, Reaction Systems will develop new sorbents that will outperform SA9T and at the same time exhibit reduced ammonia emissions. Reaction Systemsrsquo; strategy to accomplish this goal consists of two important components. The first component consists of identifying sorbents that have high probability to perform better than the SA9T. Reaction Systems has demonstrated expertise in the development of advanced sorbents for CO2 control in both EVA and cabin applications and will also employ a consultant who is an expert in gas surface interactions and in the synthesis and characterization of organic compounds. The second component of our strategy is the application of a rapid screening method that will provide accurate and relevant performance data so compounds with the highest potential can be quickly identified.