EVALUATION OF THE COMBUSTION EFFICIENCY AND EMISSION OF POLLUTANTS BYCOAL PARTICLES IN A VORTEXING FLUIDIZED-BED

Experiments were carried out in a pilot-scale (a0.45 m i.d.) vortexing fluidized bed combustor (VFBC), with coal particles as the fuel, lime stone as sorbent, and river sand as the fluidizing medium. The effects of various operating parameters on the combustion efficiency and the pollutants emitted were investigated. Different formulae for the combu stion efficiency are compared. A combustion efficiency of 96% can be e asily obtained in a VFBC. Both the NOx and SOx emissions, based on an oxygen content of 6 vol.% in the Rue gas, are found to be below 100 pp m. The retention of sulfur by limestone displays a maximum temperature in the bed at 850-880 degrees C. (C) 1997 by The Combustion Institute .