Thermal exposure from large scale ethanol fuel pool fires

• First tests of large scale (254 m2) ethanol fuel pool fires are presented.
• Impact from ethanol-rich fuels scale differently with size than that of oil-rich.
• For small fires (~1 m2), ethanol-rich fuels radiate less than gasoline-rich fuels.
• For large fires (>100 m2), ethanol-rich fuels radiate more than gasoline-rich fuels.

The growing use of ethanol as fuel for combustion engines has dramatically increased the need for large scale storage of ethanol in tanks. There are new risks related to fires in storage tanks having larger volumes. Very little experimental data exist to support risk assessments regarding emitted radiation and burning rate for large pool fires. Experience from small scale tests show that the exposure to nearby surroundings is less for alcohols than for hydrocarbon fuels like gasoline and these results are often extrapolated to fires of large sizes. This paper describes the results of two pool fires conducted within the frame of the ETANKFIRE project, one with 97% ethanol and 3% gasoline and the other with 85% ethanol and 15% gasoline, both with a surface area of 254 m2. The results show, contrary to experience from small scale pool fires, that the exposure to nearby surroundings is much larger for ethanol-rich fuels compared to the calculated radiative heat flux from a pure gasoline fire of same fuel area.