Development of a Regenerable Metal Oxide Sheet Matrix CO2 Removal System

Hamilton Standard has developed a non-venting Metal Oxide Regenerable EMU CO₂ Removal Subsystem (MORES) for the NASA Johnson Space Center. This system has the potential for application to an Advanced EMU or retrofit to the existing Shuttle EMU. The MORES system uses a catalyzed, silver based metal oxide to achieve the CO₂ removal during Extravehicular Activity (EVA) and uses no supplemental cooling. Regeneration is easily accomplished using cabin air in a simple hot air regeneration process.

The MORES technology has been demonstrated in a full size EMU Contaminant Control Cartridge (CCC) using a conventional packed bed and also an improved sheet matrix configuration. The packed bed MORES used pellets encased in a porous shell to meet the design performance goal of 3.5 - 5 hours per simulated EVA for more than 50 cycles. The sheet matrix configuration has demonstrated performance of 6 - 8 hours for greater than 50 cycles. In both cases performance is a function of total system pressure. Decreasing system pressure produces reduced system performance. Enhancements to system performance have been achieved using chemical additives as well as various cooling techniques. However, total system weight, volume and complexity will increase with incorporation of an active cooling system.

This paper details the history and current status of the MORES development activity at Hamilton Standard. NASA has funded (NAS9-17822) the latest development phase which includes a performance goal of 8 hours. In addition the system pressure drop must be less than 1.8 mm Hg and the sorbent must be capable of operating for 100 absorb/desorb cycles without replacement.