(46e) Hot Surface Ignition of Gasoline, E85, Diesel and E-Diesel

While ignition of flammable and combustible liquids by hot surfaces is a well-known hazard in the chemical processing, automotive and aviation industries, only a limited amount of research has been conducted to understand the ignition mechanism. Recent studies [1-3] have been conducted to better understand this phenomenon for common fluids and fuels in the automotive industry. However, there are very few data on the ignition characteristics of the increasingly popular automotive bio-fuels, such as E85 and E-diesel. E85 is composed of 85% ethanol and 15% gasoline, whereas E-diesel is a blend of standard No. 2 diesel fuel containing up to 15v% ethanol and a proprietary additive to maintain blend stability and certain fuel properties such as cetane number and lubricity. Currently E-diesel fuels are considered experimental. They can be used legally in off-road applications but for on-road use special permission must be obtained from the U.S. Environmental Protection Agency (EPA). In this paper, we present the results from over 600 ignition tests using a reproducible testing apparatus which includes: a temperature controlled hot plate, a controlled volume of liquid injected onto the hot surface and a fairly quiescent environment. Tests were conducted to study the ignition characteristics of the bio-fuels and compare the results to commonly used gasoline and diesel. Hot surface ignition tests were conducted using 100% ethanol, E85, gasoline, diesel and E-diesel. Based on the results of the tests, the propensity for the various fuels to ignite on a hot surface was addressed.

Reference: 1. Colwell, J.D., and A. Reza. ?Hot Surface Ignition of Automotive and Aviation Fluids,? Fire Technology, 41(2):99-117, 2005. 2. Davis, S., Chavez, D. and Kytomaa, H. ?Hot Surface Ignition of Flammable and Combustible Liquids,? SAE Paper 2006-01-1014, SAE World Congress, Detroit, MI, April 3-6, 2006. 3. LaPointe, N.R., Adams, C.T., and Washington, J, "Autoignition of Gasoline on Hot Surfaces" Fire & Arson Investigator, Oct. 2005: pp. 18 - 21.