Influence of failure modes on PAH emission during lab-scale incineration

ABSTRACT In this report the effect of process failure modes on aromatic and polv nuclear aromatic compounds during the lab-scale incineration of municipal sludge is examined. The thermal, temporal, and fuel-oxidant mixing failure modes were tested. They were respectively simulated by holding the primary thermal exposure at 400°C and varying the afterburning between 500 and 1100°C, the afterburning residence time between 1 and 3 s, and the combustion oxygen using almost stoichiometric (30%) and large excess (160%). Results indicate that the thermal failure mode is the most important factor controlling the number of compounds emitted at an afterburning temperature below 700°C. At higher temperatures the number and amounts of aromatic and polynuclear aromatic compounds emitted are controlled by the fuel-oxidant mixing failure. It was found that, when fuel oxidant mixing failure was active, the formation of 20 aromatic and poly nuclear aromatic compounds was observed even at an afterburning temperature as hig...