An advanced system for removing CO2 and H2O from cabin air, reducing the CO2, and returning the resulting O2 to the air is less massive than is a prior system that includes two assemblies — one for removal and one for reduction. Also, in this system, unlike in the prior system, there is no need to compress and temporarily store CO2. In this present system, removal and reduction take place within a single assembly, wherein removal is effected by use of an alkali sorbent and reduction is effected using a supply of H2 and Ru catalyst, by means of the Sabatier reaction, which is CO2 + 4H2 → CH4 + O2. The assembly contains two fixed-bed reactors operating in alternation: At first, air is blown through the first bed, which absorbs CO2 and H2O. Once the first bed is saturated with CO2 and H2O, the flow of air is diverted through the second bed and the first bed is regenerated by supplying it with H2 for the Sabatier reaction. Initially, the H2 is heated to provide heat for the regeneration reaction, which is endothermic. In the later stages of regeneration, the Sabatier reaction, which is exothermic, supplies the heat for regeneration.
This work was done by Gokhan Alptekin, Margarita Dubovik, and Robert J. Copeland of TDA Research, Inc., for Johnson Space Center. For further information, contact the Johnson Commercial Technology Office at (281) 483-3809. MSC-23480-1/4523-1