An experimental investigation of fuel sulfur-fuel nitrogen interactions in low-pressure premixed flames

• Published in: Symposium, International, on Combustion Vol. 20; no. 1; pp. 761 - 768
• Main Authors: Tseregounis, Spyros I., Smith, Owen I.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 1985
• ISSN: 0082-0784
• DOI: 10.1016/S0082-0784(85)80566-X

In this paper we report the results of an experimental investigation of the structure of six premixed, burner stabilized, low pressure H 2/O 2/Ar flames, each of which was seeded with C 2N 2 or C 2N 2/SO 2 mixtures. These flames range in equivalence ratio from 1.27–1.77 and in pressure from 35–88 torr (4.7–12.×10 4 dynes cm −2). A molecular beam-mass spectrometer system was used to determine the structure of each flame. Stable reactants, products and intermediates (H 2, O 2, H 2O, C 2N 2, HCN, CO, CO 2, NO and N 2) were monitored quantitatively along with the major radicals (H, O, OH). The addition of small amounts of SO 2 to the flames was found to affect the H, O and OH concentrations. The concentration of each was lowered, with the depletion of atomic hydrogen being especially large. This effect was most noticeable in the high pressure (88 torr) flame closest to stoichiometric (=1.29). NO was formed rapidly in the reaction zone of each flame. In the absence of sulfur, it was consumed further downstream at a rate which increased with both pressure and equivalence ratio. For the sulfur seeded flames, essentially no consumption was observed in the past reaction zone, leading to increased NO emissions. The structure of these flames was found to be qualitatively consistent with NO consumption via H+NO+M=HNO+M HNO+H=NH+OH HNO+H=NO+H 2 NH+NO=N 2+OH and sulfur catalyzed radical recombination via H+SO 2+M=HSO 2+M H+HSO 2=H 2+SO 2 OH+HSO 2=H 2O+SO 2