Benzo(a)pyrene, benzo(a)anthracene, and dibenzo(a,h)anthracene emissions from coal and waste tire energy generation at atmospheric fluidized bed combustion (AFBC).

The main aim of this work was the analyzing of the release to the atmosphere of benzo[a]pyrene (BaP), dibenzo(a,h)anthracene (D(a,h)A), and benzo[a]anthracene (BaA), three of the most carcinogenic PAHs listed by US-EPA as priority pollutants, emitted from combustion at the last generation reactors used nowadays in power generation, fluidized bed reactors, trying to establish their incidence when waste materials are used as "new fuels". BaP, D(a,h)A, and BaA emissions, once collected in the sampling system, have been analyzed by fluorescence spectroscopy in the synchronous mode (FS) after extraction by ultrasonic bath with dimethylformamide (DMF) as solvent. Concerning to the combustion variables influence, the conclusion reached was that, in coal combustion, the lowest emissions of BaP are generated at percentages of excess oxygen of 20%, at flows corresponding to good fluidization conditions, 860 L/h (double of the minimum fluidization velocity) and temperatures out of 850 degrees C; the lowest emission of D(a,h)A are emitted at 20% excess oxygen, 900 L/h and out of 750 degrees C, and the lowest emission of BaA are generated at 20% excess oxygen, 860 L/h and out of the range 750-850 degrees C. Regarding tire as nonfossil fuel, higher emissions of BaP, BaA, and D(a,h)A are detected in comparison to coal combustion. In coal-tire blend, the BaP, BaA, and D(a,h)A emissions are more similar to the values obtained in coal combustion and not intermediate values as it could be expected by the blend composition.