Reduction of NO emissions from a coal-fired fluidized bed combustor by addition of NH/sub 3/ through a water-cooled injector

Journal Article · Tue Nov 01 04:00:00 EST 1988 · Combust. Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(88)90015-6· OSTI ID:6471447

Wittler, W; Rotzoll, G; Schugerl, K ^[1]

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1. Institut fur Technische Chemie, Univ. Hannover (DE)

To reduce NO emissions, ammonia was injected into a coal-fired fluidized bed combustor having a diameter and expanded bed height of 30 cm and a freeboard height of 100 cm. The injector consisted of a water-cooled stainless steel tube that could be moved axially to adjust the injection height. Experiments were performed to investigate the optimal position for NH/sub 3/ addition, and the influence of coal type and operating conditions, such as the fluidization number ..mu../..mu../sub mf/, the NH/sub 3/:NO molar ratio ..beta.., the excess air level and the temperature. A distinct optimal position in the axial coordinate was always found, and depends on the fluidization number and coal type. The amount of NO reduction increases with ..beta.., with minimal reduction levels of 70% at ..beta.. = 2 and a temperature of 850/sup 0/C. The amount of excess air was also found to have an important influence on the NO reduction: optimal results were obtained at about 5% O/sub 2/ in the flue gas. The rather low temperature level at which the reaction proceeds, and the weak temperature dependence seem to indicate that the NO-NH/sub 3/-O/sub 2/ reaction is influenced by heterogeneous reaction steps in the environment of the fluidized bed combustor.

• OSTI ID: 6471447
• Journal Information: Combust. Flame; (United States), Journal Name: Combust. Flame; (United States) Vol. 74:2; ISSN CBFMA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000* -- Coal
Lignite
& Peat-- Combustion
42 ENGINEERING
421000 -- Engineering-- Combustion Systems
AIR FLOW
AIR POLLUTION ABATEMENT
ALLOYS
AMMONIA
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL
COAL RANK
COMBUSTION
COMBUSTION CONTROL
COMBUSTION KINETICS
COMBUSTION PRODUCTS
COMBUSTORS
CONTROL
DATA
ELEMENTS
EMISSION
ENERGY SOURCES
EVALUATION
EXPERIMENTAL DATA
FLUE GAS
FLUID FLOW
FLUIDIZED-BED COMBUSTION
FLUIDIZED-BED COMBUSTORS
FOSSIL FUELS
FUEL-AIR RATIO
FUELS
GAS FLOW
GASEOUS WASTES
HIGH ALLOY STEELS
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
KINETICS
MATERIALS
MINIMIZATION
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NITROGEN OXIDES
NONMETALS
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
POLLUTION ABATEMENT
REACTION KINETICS
STAINLESS STEELS
STEELS
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
TUBES
WASTES