Method and combustor for combusting hydrogen

A combustor for diffusion combustion of hydrogen fuel and air as an oxidizer in a combustion chamber in which exhaust gas including nitrogen oxides NOx is produced during combustion, said combustor comprising a burner surface area facing into said combustion chamber (CC), a number of hydrogen fuel inlet through-holes in said combustor for feeding a corresponding number of hydrogen jets (31) into said combustion chamber, a number of air inlets in said combustor for feeding air streams (30) into said combustion chamber, said hydrogen fuel inlet through-holes and said air inlets being so positioned relative to each other and relative to said combustion chamber that stable and distinct diffusive microcombustion flames are formed in said combustion chamber by diffusion micromixing hydrogen jet and air jets with a mixing intensity that depends on a pressure drop available in said combustion chamber to sustain a multitude of said stable and distinct diffusive microcombustion flames for maintaining said nitrogen oxides NOx at most at a level of 10×10−6 cubic foot of NOx per cubic foot of said exhaust gases during combustion as measured at atmospheric burner entrance conditions, said combustor further comprising a plurality of hydrogen distribution channels (26) with air flow spaces between said channels, channel walls enclosing each of said hydrogen distribution channels, said channel walls including wall sections forming at least part of said burner surface area facing into said combustion chamber (CC), said through-holes (27) formed in said wall sections for feeding hydrogen jets (31) through said through-holes (27) into said combustion chamber (CC), said through-holes (27) extending through said wall sections so that a hydrogen flow direction of said hydrogen jets (31) extends at a first angle to a surface of said wall sections, and a grid structure (28) with cut-outs (29) in said grid structure (28) for controlling an air flow direction (30) of said air jets (30) passing through said grid structure (28), said grid structure (28) being so positioned relative to said through-holes (27) that said air jets (30) passing through said cut-outs (29) and said hydrogen jets (31) passing through said through-holes (27) cross one another at a second angle to form said stable and distinct diffusive microcombustion flames.