Analysis of Chemical and Microbial Components Adsorbed on the Ion Exchange Bed in the Oxygen Generation System Recirculation Loop



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47th International Conference on Environmental Systems


Since 2007, the Oxygen Generation System (OGS) on board the International Space Station (ISS) has been producing oxygen for crew respiration via water electrolysis. As water is consumed in the OGS recirculating water loop, make-up water is furnished by the ISS potable water bus. During the operation of OGA on ISS, the recirculation loop water chemistry has experienced some changes, upsets, and recoveries. In early 2011, acidic byproducts from degradation of the cell stack membrane drove the recirculation loop pH well below neutral. Near neutral pH was recovered via ISS crew installation of a mixed resin deionizing bed (ACTEX-311) in the recirculation loop in May 2011. The ACTEX-311 removes the acidic byproducts of cell stack membrane degradation to keep the loop water pH near neutral which helps to minimize metallic corrosion and membrane degradation, and the ion exchange resin in the ACTEX-311 is also known to reversibly adsorb dimethylsilanediol (DMSD). To better understand the transport of acidic byproducts, DMSD, and any other species adsorbed by the ACTEX-311, a unit was returned to ground for sampling and analysis of the water and resin. The results of this cooperative effort are presented along with their implications for future ACTEX-311 installation.


Elizabeth Bowman, The Boeing Company, USA
Eric Cramblit, The Boeing Company, USA
Danielle Bowman, The Boeing Company, USA
Darren Dunlap, The Boeing Company, USA
Mark Wilson, The Boeing Company, USA
Ahmed Ghariani, Jacobs Technology, Inc., USA
Omoniyi Obashe, The Boeing Company, USA
Steve Van Keuren, Anadarko Industries, LLC, USA
ICES404: International Space Station ECLS: Systems
The 47th International Conference on Environmental Systems was held in South Carolina, USA on 16 July 2017 through 20 July 2017.


oxygen generator, OGS, OGA, ISS