2019-06-242019-06-242019-07-07ICES_2019_353https://hdl.handle.net/2346/84597Sandra Guerrero, Hamilton Sundstrand Corporation (HSC)-UTC Aerospace Company, USAJames Auman, Hamilton Sundstrand Corporation (HSC)-UTC Aerospace Company, USARobert Boyle, National Aeronautics and Space Administration (NASA), USAThomas Chase, Hamilton Sundstrand Corporation (HSC)-UTC Aerospace Company, USADaniel Goberman, United Technologies Research Center (UTRC), USABrian Macias, National Aeronautics and Space Administration (NASA), USATimothy Nalette, Hamilton Sundstrand Corporation (HSC)-UTC Aerospace Company's retiree, USAICES402: Extravehicular Activity: PLSS SystemsThe 49th International Conference on Environmental Systems as held in Boston, Massachusetts, USA on 07 July 2019 through 11 July 2019.The metal oxide (METOX) CO2 scrubber technology was developed by UTAS in the early 1990s as a replacement for non-regenerable LiOH canisters used in NASA’s Extravehicular Mobility Unit (EMU) system or space suit. METOX has been the main CO2 scrubber since 1998, utilizing a silver oxide sorbent and alkali metal salts to capture metabolically produced CO2 in the form of silver carbonate which is thermally regenerated to silver oxide after each use. In 2015 a performance reduction in one of the Metox canisters was observed and while the system still met the established CO2 removal requirements, the causes leading to the performance reduction have not been clearly justified. However, one of the most likely reasons is suspected to be the deactivation or degradation of the sorbent material within the system. Therefore, United Technologies Aerospace Systems, (UTAS) in collaboration with United Technologies Research Center (UTRC), is conducting a study to investigate the potential sorbent degradation mechanisms. The preliminary testing will focus on the identification of potential contaminants in addition to any changes in crystalline structure, morphology and surface area of sorbent samples extracted from the “as returned from orbit” METOX canisters and comparing the results to a prepared baseline Metox sorbent sample. Additionally, the effect of thermal desorption at a temperature above the nominal regeneration temperature will be evaluated on these sorbent samples while collecting the desorbed gases for further trace contaminant analysis. Potential oxidation of gas phase contaminants and implication on reaction kinetics will also be addressed. Some of the analytical techniques used in the study will include: X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) with Electron Dispersive Spectroscopy (EDS), Thermal Desorption with Gas Chromatograph Mass Spectroscopy (GC/MS), and Brunauer-Emmett-Teller (BET) for surface area determination. This paper summarizes the preliminary test results, and discusses potential mechanisms of sorbent degradation.application/pdfengEVA= Extra-Vehicular ActivityEMU=Extra-Vehicular Mobility UnitMetox=Metal OxidePLSS=Portable Life Support SystemPresentations