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

Patent · Wed Dec 31 23:00:00 EST 1997

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, Pittsburgh, PA, and Morgantown, WV
• 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

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