Incident Report Subject: Two Reports from The National Renewable Energy Laboratory (NREL) Date of Email report: Tue 21/09/2010 Report Detail: The first report was published in 2008, Experimental and Modeling Study of the Flammability of Fuel Tank Headspace Vapors from High Ethanol Content Fuels, and the second in 2010, Experimental and Modeling Study of the Flammability of Fuel Tank Headspace Vapors from Ethanol/Gasoline Fuels, Phase 2: Evaluations of Field Samples and Laboratory Blends. Quoting from the first report, "Gasoline is so volatile at most ambient temperatures that the headspace vapors in the tank are actually too rich to burn, as long as some liquid fuel remains. However, as temperature drops, or as the liquid fuel level goes down, the volatility of the fuel decreases. As the liquid level drops, there is less fuel vapor mixed with the air in the tank. If the ambient temperature is cold enough and the tank is nearly empty, then the fuel-air mixture in the tank becomes flammable and can pose an explosion hazard if ignited. Ethanol by itself in a fuel tank produces headspace vapors that are flammable at room temperature and over a broad range of commonly encountered ambient temperatures.... Ethanol/gasoline blends generally have volatility characteristics between those of the two major constituents.... The extent of the difference, and hence of any increased risk, depends on composition of the gasoline part of the blend and how much gasoline is present in the fuel mixture." Extract from: STI - Tank Talk September 2010 Additional Documentation: |
