Comprehensive Evaluation of Electrochemical Hydrogen Separator as Hydrogen Recovery Solution for Plasma Pyrolysis Assembly



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2024 International Conference on Environmnetal Systems


The previously tested State-of-the-Art (SOA) air revitalization architecture onboard the International Space Station recovers approximately 50% of the oxygen (O2) from metabolic carbon dioxide (CO2) via the Sabatier process. Maximum O2 recovery is required to reduce resupply mass for long-duration manned missions. O2 recovery is constrained by the limited availability of reactant hydrogen (H2) from water (H2O) electrolysis, and Sabatier-produced methane (CH4) is vented as a waste product resulting in a continuous loss of reactant H2. The Plasma Pyrolysis Assembly (PPA) has the potential to substantially increase O2 recovery by post-processing the Sabatier-produced methane to recover H2. The PPA decomposes CH4 into predominately H2 and acetylene (C2H2). A separation system is needed to purify the H2 from the PPA stream before it is recycled back to the Sabatier reactor. Two sub-scale electrochemical H2 separation systems, developed by Skyre, Incorporated, were delivered to NASA for evaluation. Complimentary of the previous submittal, ICES-2023-260, this paper reports a summation of Phase I and Phase II testing and evaluation of the C2H2 removal systems as well as lessons learned.


Kagen Crawford, NASA Marshall Space Flight Center, USA
Cara Black, NASA Marshall Space Flight Center, USA
Travis Quillen, Jacobs Technology, Inc., USA
ICES302: Physico-Chemical Life Support- Air Revitalization Systems -Technology and Process Development
The 53rd International Conference on Environmental Systems was held in Louisville, Kentucky, USA, on 21 July 2024 through 25 July 2024.


plasma, pyrolysis, PPA, oxygen recovery, O2 recovery, electrochemical cell stacks, CO2 reduction, carbon dioxide reduction, methane post processor, ECLSS, closed-loop, hydrogen recovery, microwave technologies, environmental systems