Emissions from mesoscale in-situ oil (diesel) fires : emissions from the Mobile 1998 experiments

Intensive laboratory tests and tank test conducted over a period of nine years showed that the nature and concentrations of emissions in the atmosphere from in-situ combustion of offshore oil represented a fair tradeoff when compared with the environmental risks and cleanup costs of shoreline pollution. In 1998, the U.S. Environmental Protection Agency, in collaboration with Environment Canada, implemented a series of mesoscale burns in order to assess fire-resistant booms and to study the emissions from diesel oil burns. The burns took place at the Fire and Safety Test Detachment at Little Sand Island, near Mobile Bay, Alabama. Monitoring and sampling took place at nine downwind ground stations, one upwind ground station, and six side stations. Real time particulate analysers and high volume samplers were utilized to measure particulates. The analysis concentrated on polycyclic aromatic hydrocarbons (PAH). It was discovered that water under the burns, as well as the burn residue contained small amounts of PAH. The concentration in the residue was approximately the same as in the oil before the burn, but there was a small differential concentration increase in some higher molecular weight species in the residue. The combustion gases (carbon dioxide, sulphuric acid aerosols and sulphur dioxide) were very low and sometimes negligible. Summa canisters were used to measure the volatile organic compound (VOC) emissions. The authors managed to identify and quantify more than 100 compounds, most of which did not pose a health hazard since the concentrations were low. 5 refs., 18 tabs., 5 figs