Homogeneous formation of NO and N2O from the oxidation of HCN and NH3 at 600–1000°C

Formation of HNCO, HCN, and NH3 from the pyrolysis of bark and nitrogen-containing model compounds

“…CH 4 was measured with the second NDIR instrument. HCN, NH 3 , and HNCO were analyzed with the FTIR. The data acquisition times were 1 s for all instruments except the FTIR, which had a data acquisition time of ≈3 s. In order to prevent NH 3 from being catalytically destroyed at the metallic junction connecting the ceramic gas sampling probe in the reactor with the filter placed on top of the reactor top plate, or in the filter, the gases were cooled to ≈300-400 • C in a water-cooled fourth zone of the quartz glass reactor, ≈100 mm long, located between the third zone of the reactor and the reactor's top plate (Fig.…”

“…Although the concentrations of NH 3 were quantified with higher accuracy than the HCN concentrations for bark at 700 and 800 • C, the accuracy was not high enough to be completely satisfactory in these experiments. 3 were identified as pyrolysis products from all five fuels at all temperatures used in this study. HNCO could be identified in all spectra from whey, soya bean, and yellow pea.…”

“…The question of whether the volatile nitrogen species are NH 3 , HCN, or some other compounds is crucial for the results of the modeling. Gas combustion experiments, as well as kinetic modeling of combustible mixtures doped with HCN, have revealed that HCN forms NO and N 2 O under combustion [1][2][3]. In mixtures doped with NH 3 , NO is formed, while N 2 O formation is negligible [1][2][3].…”

“…Gas combustion experiments, as well as kinetic modeling of combustible mixtures doped with HCN, have revealed that HCN forms NO and N 2 O under combustion [1][2][3]. In mixtures doped with NH 3 , NO is formed, while N 2 O formation is negligible [1][2][3]. HNCO has not been as thoroughly investigated as HCN and NH 3 but the formation of N 2 O is mainly a result of the reaction (1) NCO + NO → N 2 O + CO.…”

“…These studies revealed that HCN, NH 3 , and HNCO are the main pyrolysis products from proteins and that the amino acid composition of the protein greatly affects the distribution of nitrogen between the solid residue and the gas phase as well as the HCN/NH 3 selectivity. Since the amino acid composition of the proteins greatly affects the selectivity between volatile nitrogen and char nitrogen as well as the selectivity of the different volatile nitrogen-containing species, it is important to choose proteins that have amino acid compositions similar to those found in biomass when using proteins as model compounds [6].…”