Particulate matter (PM) emissions from ships are increasingly posing health risks to population living along coastal areas. However, studies on the characteristics of particulate emissions from ships fueled with heavy fuel oil (HFO) are quite rare. In this paper, the characteristics of the PM sampled from the exhaust of a low-speed two-stroke common-rail marine diesel engine fueled with HFO are investigated at different loads. The thermal/optical carbon analyzer was employed to discriminate the elemental and organic carbons (EC and OC), the combustion-based elemental analysis was performed to obtain the C/H ratio, and the nuclear magnetic resonance spectrometer was used to analyze the molecular structure of the sample. With increasing loads, the EC/OC and C/H mass ratios and the mole ratio of polycyclic aromatic hydrocarbons to aliphatic hydrocarbons increase. From transmission electron microscopy images, noticeable changes in nanostructure, size, morphology, and nanostructural parameters of soot particles were analyzed. Furthermore, the elemental spatial distribution in soot particles was observed by energy-dispersive X-ray spectroscopy mapping. The main elements were detected by point-analyzed spectra. These results are believed to be valuable references for hazard evaluation and building a strategy of reducing particulate emissions from low-speed marine diesel engines.
Keyphrases
- particulate matter
- high resolution
- air pollution
- magnetic resonance
- electron microscopy
- municipal solid waste
- life cycle
- climate change
- atrial fibrillation
- deep learning
- ionic liquid
- heavy metals
- optical coherence tomography
- convolutional neural network
- machine learning
- solid phase extraction
- dual energy
- gas chromatography mass spectrometry
- density functional theory
- molecular dynamics
- liquid chromatography