Ship particulate exhaust characterization: microstructure, elemental composition, surface chemistry
Résumé
Ship transport emission into relatively clean marine environment contributes significantly to the local and regional air quality and climate. A particulate emission from marine transport attracts the attention because of its possible impacts on clouds and the radiation budget. Also in harbors areas ship emission residuals particles are considered to be dangerous for human health. In spite of the important role of ship particulate exhaust its detailed characterization like size, microstructure, and chemical composition are still not well described in the literature.
The present work is devoted to the in-depth analysis of heavy fuel oil exhaust particulates. Sampling is performed on container ship with the main diesel engine Kincaid B&W 6L90. Heavy fuel oil is typically highly polluted with sulfur, vanadium, iron, sodium, nickel, and calcium etc. Individual particles microstructure and its chemical elemental composition were determined by Transmission Electron Microscopy (TEM), Energy Dispersive Spectroscopy (EDS) and Selected Area Electron Diffraction (SAED). It was found that the ships exhaust particles are resented by three groups. Soot particles dominate in the submicrometer fraction, spherical char particles present in the micrometer fraction. As well in the micrometer fraction there are char-mineral particles which are highly polluted by vanadium, nickel, calcium etc. Presents of char and char-mineral particles was found to be typical for heavy fuel oil combustion. We have also observed separated ash/mineral particles which are mostly made of metal and mineral compounds. Typically it was Ca-containing particles, in particular CaO.
Fourier Transmission Infrared (FTIR) spectroscopy proves carbonaceous nature of ship particulate exhaust and shows presents of oxygen and sulfur-containing functional groups on the surface.
Origine : Fichiers produits par l'(les) auteur(s)