NITROGEN-DOPED C-13 MATERIALS AS MODELS FOR THE RELEASE OF NOX AND N2O DURING COAL CHAR COMBUSTION

The gasification of carbon-13 doped with nitrogen was used as a model for coal char gasification. The nitrogen was inserted into the carbon-13 by treatment with ammonia at high temperatures. N2O and N2 could thus be distinguished from CO2 and CO respectively in a thermogravimetric analysis-mass spectrometry instrument. The results of temperature-programmed gasification in oxygen-argon mixtures showed that the nitrogen in the carbon matrix was gasified to nitric and nitrous oxides with clearly bimodal gas evolution profiles, whereas the corresponding carbon monoxide and carbon dioxide profiles were symmetrical. The results are interpreted in terms of the gasification of different types of nitrogen functionality.