Feasibility of removing gaseous contaminants from manned space-cabin atmospheres by ionic processes. AMRL-TR-66-22.

The application of ionic processes to the purification of manned space-cabin atmospheres was investigated in anticipation of a need for a radically new atmospheric purification system for some of the presently scheduled space jaurneys. Processes considered are (1) ion-molecule reactions of contaminant mulecules with specific added molecule ions (O0, 0) and (2) clustering of contaminant molecules about specific ions (d30+). Either reaction type can lead to charging of the contaminant molecules (or molecules derived therefrom), allowing collection by an externally applied electric field. Ion-molecule reactions were found to be potentially useful for removal of a large class of contaminant species. However, charge-trapping reactions involving such species as water and oxygen--occurring or energetically capable of occurring concurrently or subsequently to the desired reaction--could interfere, thereby allowing no clear-cut decision as to the applicability of ion-molecule reactions to purification. Clustering was investigated in greater detail than ion-molecule reactions. Detailed calculation of ion-polar molecule interaction energies for typical molecules were carried out to better accuracy than has been done heretofore. Competing reactions with water molecules will occur in the presence of water vapor. However, if the ecological balance of the cabin would allow nearly complete and specific removal of water vapor, then clustering could be used to remove highly polar contaminants. A short experimental program to demonstrate feasiUility is recommended.