Reburning thermal and chemical processes in a two-dimensional pilot-scale system. Report for May 1983-June 1984

Technical Report · Sat Mar 01 04:00:00 EST 1986

OSTI ID:5695060

Lanier, W S; Mulholland, J A; Beard, J T

The paper describes an experimental investigation of the thermal and chemical processes influencing NOx reduction by natural gas reburning in a two-dimensional pilot-scale combustion system. Reburning effectiveness for initial NOx levels of 50-500 ppm and reburn stoichiometric ratios of 0.75-1.0 is evaluated in the low-temperature environment (< 1500K) and simple aerodynamics of a firetube package boiler. Both input/out and in-flame sampling trials are reported to provide insight into the controlling kinetic mechanisms. An overall reaction order between 1.5 and 1.6 was observed with respect to initial NO. N/sub 2/ formation is observed to occur in both the fuel-rich reburning and fuel-lean burnout zones. NO destruction in the reburning zone is attributed to the reaction CH + NO yields HCN + O; < 1 ppm CH radical is required to produce the observed trends in nitrogenous species. Burnout-zone N/sub 2/ formation is influenced by total fixed nitrogen speciation with low fractional conversion of HCN and NH/sub 3/. Under low primary NO conditions, the reaction CH + N/sub 2/ yields HCN + N becomes important and is a contributor to reduced reburning effectiveness.

• Research Organization: Environmental Protection Agency, Research Triangle Park, NC (USA). Air and Energy Engineering Research Lab.
• OSTI ID: 5695060
• Report Number(s): PB-86-166741/XAB; EPA/600/D-86/048
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
421000 -- Engineering-- Combustion Systems
500200* -- Environment
Atmospheric-- Chemicals Monitoring &amp; Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION ABATEMENT
BURNERS
CHALCOGENIDES
CHEMICAL REACTIONS
COMBUSTION
CONTROL
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS BURNERS
GAS FUELS
GASES
KINETICS
NATURAL GAS
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
POLLUTION ABATEMENT
REACTION KINETICS
THERMOCHEMICAL PROCESSES