In this research, particulate emissions from a marine diesel engine were measured using a dilution system according to JIS B 8008 and the soluble organic fraction (SOF) in the particulate matter (PM) was extracted by a Soxhlet extractor. Then, the SOF was analyzed by a thermo-gravimetric analyzer to determine its origin. Total hydrocarbon (THC) concentrations in the upstream and downstream of the dilution system were also measured using a hydrocarbon analyzer to evaluate how much THC passes through the PM collection filter of the dilution system. The relationship between SOF and THC were investigated.
The results show that: 1) SOF consists of higher boiling point constituents of the fuel oil and lubricant; and the ratios of the former to the latter is influenced by engine operating conditions, 2) several tens of percent of THC in the exhaust gas pass through the PM collection filter, 3) there was no close correlation between SOF and THC in the engine operating conditions studied.
