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Development of a Hybrid Catalytic Gas Burner

A prototype hybrid catalytic radiant gas burner suitable for EU condensing boilers (4–25 kW) was developed based on the novel concept of a rich catalytic/homogeneous combustion with interstage heat removal. An extensive experimental campaign was carried out to validate the hybrid catalytic combustion technology through the detailed characterization of the operating features of the prototype burner with special focus on the catalytic partial oxidation reactor, which simultaneously acts as a radiant element. Methane combustion tests were conducted also in direct comparison with two low-NOx forced air commercial systems: a fully premixed gas burner stabilized with a knitted metal wire cover and a blue–flame turbulent diffusive burner with multiple swirled fuel nozzles and high-speed air injection. The novel burner shows the potential for improved performance with regard to heat transfer efficiency, pollutants emissions, stability, rangeability, and safety of operation.