EXPERIMENTAL STUDY OF PAH IN ENGINE SOOT BY ISOTOPIC TRACING

ABSTRACT

This paper describes an experimental procedure aimed at exploring the Polycyclic Aromatic Hydrocarbon (PAH) formation in engine soot and the effects of fuel composition. Experiments were conducted directly in a series Diesel engine to take into account the real heterogeneity of mixture, levels of pressure and temperature, with two different fuels (standard and water-fuel emulsion). Deuterated naphthalene was added (1000 ppm) to fuel and used as a combustion tracer. Detection of deuterated compounds in particulate matter was achieved by gas chromatography and mass spectrometry. Only deuterated pyrene and phenanthrene, and residual deuterated naphthalene (no other deuterated compound) have been detected in particulate matter. This study shows that PAH initially present in fuel can promote PAH formation and growth. A discussion about the description by HACA (Hydrogen Abstraction aCetylene Addition) mechanism of PAH exhaust formation is made.

Keywords:

• polycyclic aromatic hydrocarbon
• particulates formation
• isotopic tracer

Notes

∗Products identified during deuterated naphthalene combustion in present experiments.

(NR: Non research—: not detected species).