Chemistry and Emissions of Nitrogen Oxides (NO, N02 , N20) in Combustion of Solid Fuels II. Heterogeneous Reactions — N20
K. Svoboda, J. Čermák, and M. Hartman
Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic,
CZ-165 02 Prague
Abstract: Nitrous oxide (N20) volume fractions in atmosphere increase at an estimated rate 0.7-0.8 ppb per year. Potential anthropogenic sources of N20 include fertilization, combustion, mobile (car) sources, and atmospheric transformation of NOx to N20. Combustion of solid fuels and waste at lower temperatures (750-900 °C) presents a significant source of N20. During stages of a coal particle combustion (pyrolysis-devolatilization and char combustion) both volatile N and char N are mainly transformed to N2 + NO and partly to N20. HCN was recognized as the main precursor of N20 in volatile combustion. Char-N conversion to N20 (through various mechanisms) is affected by in seiu reduction of N20 by carbon surface and CO.Temperature has the most important effect on N20 emissions. At temperatures over 1000°C the N20 emissions are negligible. Char and CaO are in practical combustion systems the most effective catalysts for thermal decomposition of N20.
Full paper in Portable Document Format: 542a118.pdf
Chemical Papers 54 (2) 118–130 (2000)
Friday, November 27, 2015