(116b) Comparative Fire Risk of Motor Vehicle Fuels: Gasoline Vs. E-85 Ethanol

If motor vehicles switch from gasoline to E-85 ethanol, is the fire risk to the general public reduced or increased? This paper explores the fire risk associated with four accident scenarios:

? Transport from refinery to distributor (pipeline versus truck or barge),

? Transport from distributor to retail facility by truck,

? Spill during fuel dispensing to motor vehicle, and

? Motor vehicle fire following traffic accident.

Each of these scenarios represents a stage in the life cycle of the liquid fuel, from wholesale distribution and consumer usage.

In each case the risk of fire is composed of the probability of occurrence and the consequences of the fire. The probabilities were estimated from various compilations of accident statistics. Overall, the probability of an E-85 ethanol release was greater than or equal to a gasoline release. This was due to the comparative accident frequency of different transportation modes and distances involved.

The fire consequences were quantified in terms of spill area, heat release rate and radiant heat flux to nearby targets. For spills of the same size, the gasoline fire tended to be more severe than the E-85 ethanol fire. This is due to the differences in their physical properties, the enthalpies of combustion, and the emissivities of the flames.