The NO(x)-reduction efficiency of different reburning fuels was invest
igated by combustion tests on a 0.5 MW(th) pulverized fuel rig. The NO
(x) emissions could be reduced with gaseous, liquid and solid reburnin
g fuels to minimum concentrations of 110-150 ppmv NO2 (6 vol.% O2). Th
rough detailed in-flame measurements it was possible to compare the re
duction mechanisms of different reburning fuels.