Exploiting Capillary Sorbent Films for Air Revitalization aboard Spacecraft: Analysis of a Semi-Passive CO2 Scrubber



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2020 International Conference on Environmental Systems


Liquid sorbents have provided a primary means for robust carbon dioxide (CO2) control aboard submarines for decades. Unfortunately, such systems have not been adopted for use aboard spacecraft due to the fact that fine droplet sprays, thin falling films, and buoyancy-driven bubbly flows are not easily managed in the essentially gravity-free environments of orbiting spacecraft. Such applied engineering challenges have remained outstanding for the microgravity fluid physics community. As a work-around, in this research, a stable, silent capillary-driven ‘thin film’ is produced over a massively parallel network of open channels for both CO2 uptake and degas functions in a microgravity environment. Following several quantified assumptions, simple analytical models of species, heat, mass, and momentum transport are invoked providing clear design guides for a future engineering demonstration of the approach aboard the International Space Station. For critical sorbent properties such as CO2 capacity, effective diffusion rate, and concentration- and temperature-dependent viscosity, we provide the essential requirements of flow rate, size, shape, stability, power draw, and other aspects of the system. The results imply that a considerable reduction in system mass and volume is possible for the liquid sorbent approach for CO2 scrubbing when compared to the current state of the art.


Mark Weislogel, IRPI LLC, USA
Logan Torres, IRPI LLC, USA
Ryan Jenson, IRPI LLC, USA
John Graf, National Aeronautics and Space Administration (NASA), USA
Lawerance Hand, National Aeronautics and Space Administration/Ames Research Center (NASA/ARC), USA
Grace Belancik, National Aeronautics and Space Administration (NASA), USA
Darrell Jan, National Aeronautics and Space Administration (NASA), USA
Julie Levri, National Aeronautics and Space Administration (NASA), USA
ICES302: Physio-chemical Life Support- Air Revitalization Systems -Technology and Process Development
The proceedings for the 2020 International Conference on Environmental Systems were published from July 31, 2020. The technical papers were not presented in person due to the inability to hold the event as scheduled in Lisbon, Portugal because of the COVID-19 global pandemic.


carbon dioxide scrubber, liquid sorbent, capillary fluidics