Removal of oxides of nitrogen from gases in multi-stage coal combustion

Patent · Thu Jan 01 00:00:00 EST 1998

OSTI ID:871317

Mollot, Darren J ^[1]; Bonk, Donald L ^[2]; Dowdy, Thomas E ^[3]

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1. Morgantown, WV
2. Louisville, OH
3. Orlando, FL

Polluting NO.sub.x gas values are removed from off-gas of a multi-stage coal combustion process which includes an initial carbonizing reaction, firing of char from this reaction in a fluidized bed reactor, and burning of gases from the carbonizing and fluidized bed reactions in a topping combustor having a first, fuel-rich zone and a second, fuel-lean zone. The improvement by means of which NO.sub.x gases are removed is directed to introducing NO.sub.x -free oxidizing gas such as compressor air into the second, fuel-lean zone and completing combustion with this source of oxidizing gas. Excess air fed to the fluidized bed reactor is also controlled to obtain desired stoichiometry in the first, fuel-rich zone of the topping combustor.

• Research Organization: National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV (United States)
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 5706645
• OSTI ID: 871317
• Country of Publication: United States
• Language: English

Related Subjects

removal
oxides
nitrogen
gases
multi-stage
coal
combustion
polluting
gas
values
removed
off-gas
process
initial
carbonizing
reaction
firing
char
fluidized
bed
reactor
burning
reactions
topping
combustor
fuel-rich
zone
fuel-lean
improvement
means
directed
introducing
-free
oxidizing
compressor
air
completing
source
excess
fed
controlled
obtain
desired
stoichiometry
topping combustor
combustion process
coal combustion
oxidizing gas
bed reactor
fluidized bed
bed reaction
excess air
rich zone
multi-stage coal
stage coal
air fed
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