RESUMO
The aim of this study was to evaluate the emissions of polycyclic aromatic hydrocarbons (PAHs) bound to the particulate matter (PM) during the combustion of raw pyrolysis volatiles (bio-oil and pyrogas mixture) generated from the pyrolysis of rice husk. Five different raw pyrolysis volatiles were produced at varying pyrolysis temperatures (400-800°C) and subsequently combusted in a laboratory-scale, continuous pyrolysis-combustion facility at 850°C. 15 priority pollutant PAH levels in the resulting biochar, bio-oil, and PM were evaluated. Results showed that combustion of the raw pyrolysis volatiles produced at elevated pyrolysis temperatures resulted in greater concentrations of PM-bound PAHs (119% increase between 400 and 800°C) due to the increased PAH and oxy-aromatic content of the bio-oil fraction. Significantly increased benzo(a)pyrene (BaP) - equivalent toxicity of the biochar and PM was observed at elevated pyrolysis temperatures.
