NOx reduction by potassium-containing coal briquettes. Effect of NO2 concentration

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.