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Replacing ozone depleting refrigerants on U.S. Navy submarines has created new design challenges as they interface with the atmosphere control machinery. The environmentally friendly nature of new HFC's and HCFC's is in part due to their higher reactivity. Unfortunately that reactivity causes excessive decomposition resulting in toxic gas production when processed in the catalytic oxidizer, the U.S. Navy Submarine CO and H2 Catalytic Burner. The catalyst/air stream is heated to induce the decomposition of H2, CO and trace organics. An effort is underway to lower the burner temperature to minimize refrigerant decomposition. This paper discusses test results of varying catalyst temperatures when trace contaminants, representative of the submarine atmosphere, are oxidized on the burner's catalyst. The effects of water vapor and catalyst age on oxidation efficiencies are also reported. Both bench scale and full scale burner test results are discussed.

Alternate refrigerant HFC-134a has been found to be substantially more reactive than CFC-12 in the US Navy submarine catalytic burner. The burner operates at 316°C and uses a manganese dioxide/copper monoxide catalyst, Hopcalite. The reaction of HFC-134a produced hazardous quantities of HF in the outlet air in excess of the established submarine exposure limits. No other hazardous products, such as carbonyl fluoride, were detected.