COMPARATIVE QUANTITATIVE RISK ANALYSIS OF MOTOR GASOLINE, LPG, AND ANHYDROUS AMMONIA AS AN AUTOMOTIVE FUEL
Quest Consultants, for Iowa State University, June 2009
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Quest Consultants: NH3 fuel risk analysis [PDF, 750 KB]
Introduction
Quest Consultants Inc. was retained by Iowa State University to perform a quantitative risk analysis (QRA) that compared the risks associated with the bulk movement, storage, and dispensing of three automotive fuels. The fuels that were the subject of the study were automotive gasoline, liquefied petroleum gas (LPG) and anhydrous ammonia. The objective of the study was to compute the level of risk posed to the public near an average roadway along which the fuels would be transported in road tankers, and near an automotive fueling station.
The study was divided into three primary tasks.
Task 1 – Compare the potential consequences associated with an accidental release of anhydrous ammonia to the potential consequences associated with accidental releases of automotive gasoline and LPG, when used for automotive fuel.
Task 2 – Review of the frequencies associated with accidental releases of anhydrous ammonia, automotive gasoline, and LPG.
Task 3 – Evaluation of the risk level (consequence x frequency) associated with each material when used as an automotive fuel. The boundaries of the analysis will be defined by the transport of bulk material to the service station, storage of material at the service station, and loading of material
into automobiles.
Conclusions, Summary
The hazards and risks associated with the truck transport, storage, and dispensing of refrigerated anhydrous ammonia are similar to those of gasoline and LPG. The design and siting of the automotive fueling stations should result in public risk levels that are acceptable by international risk standards. Previous experience with hazardous material transportation systems of this nature and projects of this scale would indicate that the public risk levels associated with the use of gasoline, anhydrous ammonia, and LPG as an automotive fuel will be acceptable.
It is also important to note that the risk associated with traveling in a vehicle powered by any one of these fuels is dominated by accidents that do not result in a release of the fuel. As described in the National Safety Council database referenced in Section 1, very few traffic accidents result in a release of the fuel powering the automobile. Since anhydrous ammonia and LPG are stored in similar pressurized tanks, there is no reason to believe that the risks associated with the passengers in an automobile would go up or down due the use of anhydrous ammonia as the fuel.
