Distillate marine fuel oil and ULSFO spills in cold climate - oil spill characteristics and response options

Abstract

In 2014 the Norwegian Coastal Administration (NCA) conducted an environmental risk and oil spill response analysis related to possible oil spills from shipping in the areas of Svalbard and Jan Mayen. One of the key findings were that due to regulations to ban heavy fuel oil in protected areas, the most likely spill scenarios are spills of distillate marine fuel oils. Furthermore, the cold climate is expected to slow down oil weathering processes, and in calm weather situations this may call for active response, even to spills of light fuel oils. Also along the coast of mainland Norway, response options to spills of light fuel oils is an emerging topic. This includes not only MGO/MDO, but also several new products formulated to meet the 2015 Emission Control Areas (ECA) sulphur limit, also referred to as hybrid fuel oil / ultra low sulfur fuel oil (ULSFO). Previous experiences from spills of light fuel oils in Norwegian waters have been summarized; however, some recommendations for response remain inconclusive. Hence, the need for increased knowledge of the characteristics of light fuel oils and relevant response options is recognized. SINTEF analyzed a range of light fuel oils on behalf of NCA. This initial screening included chemical characterization (GC-MS/GC-FID) and identification of physical properties, i.e. viscosity, density, pour point, flash point, as well as emulsifying properties. Based on these results, five different fuel oils were selected for further examination, including:- Weathering predictions and improved trajectory modeling- Chemical and toxicological characterization of water accommodated fraction (WAF)- Laboratory tests of properties related to dispersant use and ignition, both in order to explore the applicability of dispersants and in-situ burning as response techniques, and to determine windows of opportunity for the different oil types. Laboratory tests are performed at 2 °C and 13 °C, reflecting “arctic” / cold climate conditions and North Sea summer conditions. Furthermore, mechanical recovery will be tested on the same oil types in the NCA test facility (abstract submitted by Holt & Frost). The results from this ongoing project will be presented from an operational viewpoint. They are expected to give insights useful to response planning, decision making during spill incidents, and enhanced response options for future spills of distillate marine fuel oils and ULSFO, especially in cold climates and arctic environment.