NOx Reduction by Potassium-Containing Coal Briquettes. Effect of NO2 Concentration

The reactions of a potassium-containing bituminous coal briquette and the corresponding catalyst-free char with different NO/O 2 mixtures have been investigated at temperatures between 300 and 325 °C. The isothermal reactions have been followed by two techniques: thermogravimetry and gas chromatography + chemiluminescence analysis. A NO/NO 2 mixture rich in NO 2 results in a high carbon loss compared to that corresponding to the mixture poor in NO 2 . Despite that, NO x conversion is similar for both mixtures. The extra weight loss in the presence of a high concentration of NO 2 is a consequence of NO 2 reduction by carbon, producing NO and CO 2 evolution.