The reactions of a potassium-containing bituminous coal briquette and the c
orresponding catalyst-free char with different NO/O-2 mixtures have been in
vestigated at temperatures between 300 and 325 degrees C. The isothermal re
actions have been followed by two techniques: thermogravimetry and gas chro
matography + chemiluminescence analysis. A NO/NO2 mixture rich in NO2 resul
ts in a high carbon loss compared to that corresponding to the mixture poor
in NO2. Despite that, NOx conversion is similar for both mixtures. The ext
ra weight loss in the presence of a high concentration of NO2 is a conseque
nce of NO2 reduction by carbon, producing NO and CO2 evolution.