Chemical characterization of exhaust emissions originating from the regeneration mode of a diesel particulate trap

Abstract

The chemical characterization of exhaust emissions originating from the regeneration mode of a diesel particulate trap was achieved. The regeneration process was carried out by heating the particulate trap to 700 °C for 208 min with an air stream passing through. Emissions of carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NO x ), particulates, chemical compounds present in the particulate and the semi-volatile phase were identified and quantified. The n-alkanes with carbon number ranging from C15 to C35, 15 polycyclic aromatic hydrocarbons (PAH) and 1-nitropyrene have been identified. Results obtained for a full regeneration mode were: CO, 200 mg; HC, 30 mg; NO x , 500 mg; particulates, 5.5 mg; aliphatic hydrocarbons, 90 μg; sum of 22 PAH, < 3 μg and 1-nitropyrene, < 0.02 μg respectively. A white residue obtained in the sampling device was identified as calcium sulfate hydrate. The emission factors determined show that the amount of pollutants emitted during the regeneration mode is negligible compared to emissions during the accumulation mode.