NO[sub x] removal on a coal-fired utility boiler by selective non-catalytic reduction
- Aalborg Ciserv International A/S, Aalborg (Denmark)
- Technical Univ. of Denmark, Lyngby (Denmark)
A plant for Selective Non-catalytic Reduction (SNR) of NO[sub x] emissions by NH[sub 3] (ammonia) injection has been designed, installed and successfully tested on a 135 MW[sub e] coal-fired utility boiler. The final 2000 hours test was performed with the plant automatically controlled. The NO[sub x] level in the untreated flue gas is typically 400-700 ppm, and NH[sub 3] is injected at a molar ratio to NO between 0.6 and 1.8. Through most of the load range 50-70% reduction of the NO[sub x] emission was achieved. The temperature window for the process is 850-1050[degrees]C, with an optimum at 950[degrees]C. In order to minimize the emission of unburnt NH[sub 3], natural gas was added in a molar ration to NO[sub x] of about 1 in part of the load range. The plant met a demand of no more than 15 ppm NH[sub 3] in the flue gas. The research and development work needed for adoption of the SNR-process to coal-firing has been in progress through five years in a cooperation between Aalborg Ciserv International, The Technical University of Denmark, and the Danish power plant association ELSAM. The research program included basic laboratory research on the chemical kinetics of the process, pilot scale research on the reducing capacity and emissions of ammonia and urea, testing in laboratory scale and pilot scale of several additives for widening the temperature window and minimizing the NH[sub 3] emission, and development of nozzles for good mixing of NH[sub 3] into the flue gas. The resulting concept is applicable for NO[sub x]-removal on several types of boilers. 20 refs., 10 figs.
- OSTI ID:
- 6233288
- Journal Information:
- Environmental Progress; (United States), Journal Name: Environmental Progress; (United States) Vol. 11:4; ISSN 0278-4491; ISSN ENVPDI
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
200202* -- Fossil-Fueled Power Plants-- Waste Management-- Noxious Gas & Particulate Emissions
54 ENVIRONMENTAL SCIENCES
540120 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
AIR POLLUTION CONTROL
AMMONIA
BOILERS
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTIONS
COAL
CONTROL
DENITRIFICATION
ENERGY SOURCES
FLUE GAS
FLUIDS
FOSSIL FUELS
FOSSIL-FUEL POWER PLANTS
FUEL GAS
FUELS
GAS FUELS
GASEOUS WASTES
GASES
HYDRIDES
HYDROGEN COMPOUNDS
INJECTION
INTAKE
MATERIALS
NATURAL GAS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL
POWER PLANTS
REDUCTION
REMOVAL
SELECTIVE CATALYTIC REDUCTION
THERMAL POWER PLANTS
WASTES