Nitric oxide (NO) and nitrous oxide (N2O) emissions during selective non-catalytic reduction and selective catalytic reduction processes in a pulverized coal/Ammonia Co-fired boiler

The global warming and climate change are accelerated by the emissions of CH4, chlorofluorocarbon, and N2O gases along with CO2 resulting from the use of fossil fuels. Recently, a new combustion technology that combines carbon-free ammonia (NH3) fuel and coal has been proposed to reduce CO2 emissions from thermal power plants. In this study, we examined the emission levels of NO and greenhouse gas N2O from the existing coal-fired and future carbon-neutral coal/ammonia co-fired thermal power plants. As a result, a correlation between the amounts of NO and N2O gases generated during combustion in the furnace of a thermal power plant was established, and possible relationships between NO and N2O emissions during the selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) of NOx were experimentally analyzed. In addition, a linear correlation between the CO and N2O concentrations was observed. The air-staged combustion during SCR (300 °C, urea) produced the lowest total emission concentration of NO and N2O (9 ppm) under the utilized conditions. The findings of this study can help control the emission levels of air pollutant NO and greenhouse gas N2O throughout the entire process of thermal power plants.