Hydrophobic molecular sieves have been identified as of potential interest for the adsorption of carbon dioxide (CO2) from the atmosphere of a man-inhabited spacecraft. A study was thus initiated in order to evaluate the applicability and competitiveness of the hydrophobic molecular sieves - including, notably, activated carbon, Silicalite-I, Deca-dodecasil, and Zeolite-Y - for this utilisation.
The first phase of this study was performed in three steps: a material review of the scientific community and commercially available materials, test of samples under representative conditions, and finally, the development of a breadboard design.
Based on the results of these tasks, two coconut-based activated carbon materials are felt to be potentially competitive with the currently planned solid amine and have additionally a variety of other advantages for a space application. Several other materials at a research and development stage which may eventually prove to have better performance were also identified.