Nitric Oxide Formation during Pulverized Coal Combustion

摘要

The paper discusses the formation of nitrogen oxides (NOx) during pulverized coal combustion. Data on the overall conversion of coal-nitrogen to NOx were obtained at 1250 and 1750 K for a residence time of 1 second. The conversion of coal-nitrogen to NOx decreased monotonically with increasing fuel/oxygen equivalence ratio and decreased slightly with increasing temperature. Oxidation experiments were also carried out on char to separate the contribution to NOx emissions of the char from that of the volatiles. The char used was prepared by the pyrolysis of coal at a temperature and residence time corresponding to those of oxidation experiments. The conversion to NOx of char-nitrogen was lower than the corresponding value for coal-nitrogen. It was found that volatilized nitrogen compounds accounted for a major fraction of NOx produced from coal-nitrogen, especially at high temperatures and low fuel/oxygen equivalence ratios.