Gas combustion with low no.sub.x emission

Abstract From the Canadian patent

The combustion of fuel gas to achieve improved thermal efficiency and to suppress NOx formation is conducted by adding preheat to the combustion reactants followed by flameless combustion on the outer surface of a porous fiber burner. Preferably, all of the desired combustion air is preheated by indirect heat exchange with the flue gas resulting from the flameless combustion and the preheated air is then admixed with the fuel gas fed to the porous fiber burner. Waste heat from available independent sources may also be utilized to preheat the combustion reactants.