Modeling of fluidized-bed combustion of coal. Volume II. AFBC component models. Final report. [Location and kinetics of NO-char and O/sub 2/ -CO reactions within the bed]

Technical Report · Sat May 01 04:00:00 EDT 1982

OSTI ID:6413672

Louis, J F; Tung, S E; Lee, D

A theoretical study of the mechanism of the particle entrainment phenomenon relating the particle trajectories with bubbling actions in the bed allowed the development of a backbone model for the prediction of particle mass concentration profiles in the freeboard of a fluidized bed. Simple experiments in the freeboard of MIT 0.6m x 0.6m FBC unit were used to compare with the model calculations. Good agreements have been obtained. This entrainment model takes into account the stratification effect due to density difference of particles in a multi-component fluidized bed. Satisfactory agreements have been obtained in comparing the calculated char elutriation with experimental data. This mechanistic entrainment model has also been used in conjunction with a chemical kinetic description of the NO-char reaction for prediction of the reduction of NO along the height of the freeboard in fluidized coal combustion. Oxidation of carbon monoxide along the height of the freeboard (the combustion space between the top of the bed and the first row of heat exchange tubes) of a coal burning fluidized bed is also modelled and predicted CO concentration profiles are compared with measurements obtained in MIT 0.6 x 0.6m cross section 4.5m high experimental fluidized combustor. The CO oxidation model is based on a set of twenty-two homogeneous chemical reactions as proposed by Lyon and Hardy and on an assessment of the rate of heterogeneous recombination reactions of free radicals on the surfaces of solid particles carried by the fluidizing gas stream from the bed into the freeboard.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA). Energy Lab.
• DOE Contract Number: AC21-81MC16000
• OSTI ID: 6413672
• Report Number(s): DOE/MC/16000-1294-Vol.2; ON: DE83001906
• 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
BENCH-SCALE EXPERIMENTS
BUBBLES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHARS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL
COMBUSTION
COMBUSTORS
DATA
ELEMENTS
ELUTRIATION
ENERGY SOURCES
ENTRAINMENT
EXPERIMENTAL DATA
FLUIDIZED-BED COMBUSTION
FLUIDIZED-BED COMBUSTORS
FOSSIL FUELS
FUELS
INFORMATION
KINETICS
MATERIALS
MATHEMATICAL MODELS
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PYROLYSIS PRODUCTS
REACTION KINETICS
SEPARATION PROCESSES
TESTING
THERMOCHEMICAL PROCESSES
VALIDATION