Evaluation of a Membrane Based Carbon Dioxide Absorber for Spacecraft ECLS Applications

In an on-going harmonized ESA/NIVR project, performed by Stork Comprimo and TNO-MEP, the removal of the carbon dioxide with membranes is studied. The use of membrane gas absorption for carbon dioxide removal is currently hampered by the fact that the commonly used alkanolamines result in leakage problems when using polyolefin membranes. This prevents the use of membrane gas absorption for carbon dioxide in spacecrafts. TNO has recently discovered classes of liquids for carbon dioxide absorption which are suitable for use with cheap polyolefin membranes. This opens the possibility for using membrane gas absorption for carbon dioxide control in spacecrafts.

In the project the performance of membrane gas absorption for the removal of carbon dioxide from gas streams having a chemical composition representative of spacecraft conditions are determined experimentally. Important performance parameters are, among others, the required membrane area, equipment volume and weight and the used energy for a given duty.

In this document, this new technique will be discussed and compared to other more mature carbon dioxide absorption techniques.