Release and reactions of fuel-nitrogen in a high-pressure entrained-coal gasifier

Conference · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6311784

Nichols, K M; Hedman, P O; Smoot, L D

The authors present effects of elevated pressure, flame type, and coal feed rate on fuel-nitrogen release and nitrogen pollutant formation examined in a laboratory scale entrained-coal gasifier. A Utah, high-volatile bituminous coal was used. Fuel-nitrogen release from the coal showed little dependence on oxygen-coal ratio, pressure, or coal feed rate. Values at the gasifier exit averaged 83% for the diffusion flame and 92% for the premixed flame. Fuel-nitrogen release exceeded fuel-carbon release by about 10% for the premixed flame and about 30% for the diffusion flame, depending on oxygen-coal mass ratio. Most of the fuel nitrogen was thought to be released during devolatilization. Over one-half of the released fuel-nitrogen formed N/sub 2/, with significant amounts of NH/sub 3/ and HCN, and lesser amounts of NO produced. Increased pressure at constant mass feed rates caused sharp decreases in effluent NO concentrations (to near zero) for both flame types. This NO reduction was explained by a combination of increased residence time, and increased NO decay rate, both of which resulted from increasing pressure. Elevated pressure operation also increased the effluent NH/sub 3/ concentration and decreased HCN concentration for the diffusion flame. The more complete mixing of the premixed flame resulted in lower NH/sub 3/ and HCN levels, and higher N/sub 2/ levels than the diffusion flame. In general, nitrogen species concentrations were not largely affected by coal feed rate, though increased coal feed rate decreased NH/sub 3/ levels somewhat.

• Research Organization: Brigham Young Univ., Provo, UT
• OSTI ID: 6311784
• Report Number(s): CONF-8610180-
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010900 -- Coal
Lignite
& Peat-- Environmental Aspects
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Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION MONITORING
AMMONIA
BITUMINOUS COAL
BLACK COAL
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
COAL
COAL FINES
COMBUSTION KINETICS
EMISSION
ENERGY SOURCES
FLAMES
FLOW RATE
FOSSIL FUELS
FUEL FEEDING SYSTEMS
FUEL SYSTEMS
FUELS
GASEOUS WASTES
HYDRIDES
HYDROGEN COMPOUNDS
KINETICS
MATERIALS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PRESSURE EFFECTS
REACTION KINETICS
WASTES