Pulverized-coal combustion NO/sub x/ control through fuel-staging. Final report, September 1980-August 1982. [Fuel and air staging]

Technical Report · Sun Aug 01 04:00:00 EDT 1982

OSTI ID:6875974

Kelly, J T; Pam, R L; Suttmann, S T

A 16.1-kW idealized subscale combustor was used to define the NO/sub x/ emission control benefits of fuel-staging. NO/sub x/ control is achieved by injecting coal, as well as combustion air, at two locations in the combustor. The NO/sub x/ and combustion product gases from the first stage flame are mixed with fuel and air in the second stage and reburned. The fuel fragments, fuel nitrogen components, soot and char produced by the reburning interact with previously formed NO/sub x/, reducing it to low levels within a fraction of a second. This combustion modification approach has lowered NO/sub x/ by over 70 percent from baseline levels. Test results showed that second stage stoichiometry is a dominant process variable, and that effective NO/sub x/ reduction required that the second stage be operated fuel-rich. First and third stage stoichiometries and fuel fraction injected into the second stage were less important to the process, as long as the second stage was operated under fuel-rich conditions. The NO/sub x/ reduction process was found to occur in less than 1 sec. Carbon burning efficiencies were a few percent higher or lower than conventional-staging results, depending on the first and second stage stoichiometries. Based on the test results of this study, process variable regimes were identified where fuel-staging has a distinct advantage in controlling NO/sub x/ emissions over classical air-staging. These were cases where the first stage was operated fuel-lean and the second stage was operated fuel-rich. The application of the fuel-staging process to practical combustion systems might provide designers with increased flexibility in overcoming NO/sub x/ emission problems.

• Research Organization: Acurex Corp., Mountain View, CA (USA). Energy and Environmental Div.
• DOE Contract Number: AC22-80PC30296
• OSTI ID: 6875974
• Report Number(s): DOE/PC/30296-6; ON: DE82020973
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010900 -- Coal
Lignite
& Peat-- Environmental Aspects
014000* -- Coal
Lignite
& Peat-- Combustion
AIR POLLUTION ABATEMENT
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTIONS
COAL
COAL FINES
COMBUSTION
DATA
ENERGY SOURCES
EXPERIMENTAL DATA
FOSSIL FUELS
FUELS
INFORMATION
MATERIALS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
POLLUTION ABATEMENT
SULFUR COMPOUNDS
SULFUR OXIDES
THERMOCHEMICAL PROCESSES