10 - Chemical heterogeneity in modern marine residual fuel oils

Abstract

Because of their preponderant use as fuel in marine vessels, marine residual fuels are often the focus of maritime oil spill investigations. Residual fuels, often referred to generically as heavy fuel oil or HFO, pose a variety of challenges to oil spill investigators. Variability in the composition of modern heavy marine fuels provides unique opportunities for chemical “fingerprinting” of HFOs in the environment. This chapter focuses on the forensic chemistry of HFO—the most widely used of the commercial marine fuel oils—and chemical features of these fuels pertinent to oil spill investigations. Two most popular groups of heavy fuel oils, IFO 180 and IFO 380, differ largely in their blending formulas. From a forensic chemistry standpoint, it is the combination of the refining and blending processes that impose unique chemical “fingerprints” on IFO 380 HFOs, which oil spill investigators can use to identify and track spilled fuel in the environment. Gas chromatographic analysis of petroleum fuels reveals the distinctive boiling point distribution of the chromatographable hydrocarbons that compose the fuels.