Catalytic combustion process using supported palladium oxide catalysts

Claim 1

A process for starting a combustion system to catalytically combust a gaseous carbonaceous fuel with air in a combustor in the presence of a palladium oxide-containing catalyst, which comprises: (a) predetermining a decomposition onset temperature at which the palladium oxide-containing catalyst decomposes at an oxygen partial pressure equal to that found in the combustor; (b) predetermining a reformation onset temperature at which the palladium oxide-containing catalyst will, at said same oxygen partial pressure found in the combustor, reform into palladium oxide after being subjected to the decomposition temperature; (c) utilizing a flow of hot gases from a preburner to heat said catalyst to a temperature high enough to initiate combustion of said fuel with air upon contact with said catalyst; (d) thereafter reducing the flow of hot gases from the preburner while supplying air and said fuel for combustion to the combustor downstream of said preheater; and (e) upon overheating of the catalyst to a first temperature in excess of the decomposition onset temperature of the catalyst, whereby the catalyst sustains a diminution of catalytic activity, thereafter restoring catalytic activity by lowering the temperature of the catalyst to a temperature not greater than the reformation onset temperature and maintaining the temperature at or below the reformation onset temperature until a desired degree of catalytic activity of the catalyst is achieved, and then maintaining the catalyst below the aforesaid decomposition onset temperature.