Environmental Assessment of a Commercial Boiler Fired with a Coal/Waste Plastic Mixture. Volume 1. Technical Results

摘要

The report gives results of comprehensive emissions testing and laboratory analyses of a stoker-fired commercial boiler firing a coal/waste plastic mixture. In one test, the unit fired its typical coal fuel; in the other, shredded waste polyethylene terephthalate (PET) beverage bottles were added to the coal to about 16% by weight in the mixed fuel. NOx, total unburned hydrocarbon, and solid particulate were relatively unchanged for the two tests, as was the emitted particle size distribution. SOx emissions decreased with the coal/PET fuel in keeping with its lowered sulfur content; average CO emissions were also decreased. Flue gas emissions of most trace elements were comparable for both tests, as were the trace element compositions of corresponding ash streams. However, lead emissions were significantly increased for the coal/PET fuel, reflecting an increased lead content of the mixed fuel. The cyclone hopper ash for the coal/PET test had consistently lower leachable trace element and anion content than for the coal fuel test. Total flue gas organic emissions were comparable for both tests, in the 1 mg/dscm range; although levels of several semivolatile priority pollutants were higher for the mixed fuel.