Integrated process and apparatus for control of pollutants in coal-fired boilers

Patent · Tue Nov 24 04:00:00 EST 1992

OSTI ID:7279601

Hunt, T G; Offen, G R

A method and apparatus are described for reducing SO[sub x] and NO[sub x] levels in flue gases generated by the combustion of coal in a boiler in which low NO[sub x] burners and air staging ports are utilized to inhibit the amount of NO[sub x] initially produced in the combustion of the coal. A selected concentration of urea is introduced downstream of the combustion zone after the temperature has been reduced to the range of 1300 F to 2000 F, and a sodium-based reagent is introduced into the flue gas stream after further reducing the temperature of the stream to the range of 200 F to 900 F. Under certain conditions, calcium injection may be employed along with humidification of the flue gas stream for selective reduction of the pollutants. 7 figs.

• DOE Contract Number: FC22-91PC90550
• Assignee: Public Service Co. of Colorado, Denver, CO (United States)
• Patent Number(s): US 5165903; A
• Application Number: PPN: US 7-796909
• OSTI ID: 7279601
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010800* -- Coal
Lignite
& Peat-- Waste Management
AIR POLLUTION CONTROL
CHALCOGENIDES
CHEMICAL REACTIONS
COMBUSTION
CONTROL
DENITRIFICATION
DESULFURIZATION
FLUE GAS
FLUID INJECTION
GASEOUS WASTES
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL
STAGED COMBUSTION
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
THERMOCHEMICAL PROCESSES
WASTES