Polycyclic aromatic hydrocarbons emitted from a hot-mix drum, asphalt plant: study of the influence from use of recycled bitumen

Asphalt mixing is an industrial activity of which energy consumption can reach 60% of the total energy consumed by the construction and maintenance of a road over a 30-year service life. Hot mix asphalt plant represents the most common process found in the road sector. Hot bitumen fumes however contain polycyclic aromatic hydrocarbon (PAH) compounds, and, moreover, the use of recycled bitumen can lead to generating various emissions. Polycyclic aromatic hydrocarbons may also be emitted from the process itself, a step that requires warming and drying aggregate through combustion. In the aim of minimizing emissions, it has become necessary to identify the set of major influential parameters. A joint research program involving several institutions has been laid out to conduct an experimental campaign on the Blois Hot Mix Asphalt plant, with quantification of the 16 PAH listed by the USEPA. Variations in asphalt recycling rate favour emissions of heavy molecular weight PAH, among those analysed.