Study of Air Revitalization System for space station 891576

In closed environments such as space stations, it is necessary to eliminate CO₂ produced by the metabolisms of crew members, for their life support, and to regenerate the air by supplying O₂ to make up for the deficiency. If humans are to be in space only a short time, it is in general advantageous to adsorb CO₂ with lithium hydroxide, and to supply O₂ from tanks. But when the stay in space is long, it is essential to establish a highly reliable and energy-efficient system to recover CO₂ in high concentrations and regenerate O₂ from this recovered CO₂ Fig. 1 shows the system presently conceived, which is roughly divided into the following processes: A process that removes and concentrates CO₂ from the air; a CO₂ reduction process that separates carbon from CO₂ and obtains water; and a water electrolysis process that decomposes water electrically and recovers O₂. The process deemed most promising both in terms of low energy consumption and reliability for removing and concentrating CO₂. In this process, solid amine removes CO₂ produced by human metabolisms, desorbs it, then separates and concentrates CO₂ of high purity.

Bosch reaction, which proceeds at comparatively low temperatures, is thought to be advantageous for the CO₂ reduction process, and using a solid electrolyte is advantageous for the water electrolysis process.

This research involved several tests, and simulated analysis for these processes to examine the optimum conditions for the effective operation of the system.