HYBRID CATALYTIC COMBUSTION OF METHANE/HYDROGEN MIXTURES

Hybrid catalytic combustion technology, which is a staged process comprising a preliminary catalytic partial oxidation (CPO) step followed by a homogeneous flame combustion with interstage heat removal, was tested for the first time with mixtures of methane and hydrogen. Short contact time CPO experiments were run to elucidate the effect of the progressive substitution of methane with H-2 in the fuel feed to the structured catalytic reactor, which was operated under self-sustained conditions at high temperature. Furthermore, a prototype radiant hybrid burner was realized and safely operated at atmospheric pressure with up to 80%2vol. of H-2 in the fuel and a primary equivalence ratio in the range 2.4-4.0. Outstanding NOx emission levels were attained with pure methane feed, which were also confirmed with H-2-rich fuels, due to the effective reduction of both thermal and prompt NOx formation.