Demonstration of urea-based SNCR technology on a pulverized, coal-fired, wet-bottom boiler. Final report

Technical Report · Sat Apr 01 04:00:00 EST 1995

OSTI ID:74111

The Clean Air Act Amendments of 1990 have made the control of oxide of nitrogen (NO{sub x}) emissions from utility boilers a major concern for electrical utilities. Urea-based selective non-catalytic reduction (SNCR) is one option for controlling NO{sub x} emissions. Urea is injected into the furnace and flue gases where the temperature of these gases is between 1700{degrees}F and 2200{degrees}F. The nitrogen in the urea reacts to change some of the NO{sub x} to N{sub 2} and H{sub 2}O. This process has been applied to boilers firing gas, oil, coal, and other fuels, but not to a unit with the same configuration as the wet-bottom, continuous-slagging, pulverized-coal furnaces operated at PSE&G`s Mercer Generating Station. This report provides a review of the urea-based SNCR demonstration performed from June to September 1993 on the reheat furnace of Unit 2 at Mercer Generating Station. The unit is a twin-furnace boiler capable of supporting 321 MW of generating capacity. The SNCR process was able to reduce NO{sub x} emissions by an average of 38% while maintaining an NH{sub 3} slip of 5 ppm (corrected to 7% O{sub 2}). When simulated over-fired air or air biasing was combined with the SNCR process the amount of NO{sub x} reduction was between 45% and 80% while the NH{sub 3} slip was again below 5 ppm (corrected to 7% O{sub 2}).

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States); Carnot, Tustin, CA (United States)
• Sponsoring Organization: Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 74111
• Report Number(s): EPRI-TR--105071
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
CONTROL
EMISSION
EXPERIMENTAL DATA
FOSSIL-FUEL POWER PLANTS
GASEOUS WASTES
INJECTION
NITROGEN OXIDES
PULVERIZED FUELS
REDUCTION
UREA