Retail Petroleum Equipment

4 Central Illinois Manufacturing Company Rev B March 2006 Phase Separation The worst enemy of any ethanol blend is water. The potential for Phase Separation re- quires that gasoline oxygenated with ethanol not be exposed to water during its distribu- tion or use in a vehicle. Because of this requirement, gasoline oxygenated with ethanol is usually not transported in pipelines, which sometimes contain water. Rather, the ethanol is usually added to tanker trucks at the terminal immediately before delivery to the service station. If water contaminates the fuel, the water dissolves into the ethanol and disperses through the tank. Once it exceeds the tolerance level, the alcohol water mixture will separate from the gasoline. Depending upon individual conditions, about 40% to 80% of the ethanol will be drawn away from the gasoline by the water, forming two distinct layers. The top layer will be a gasoline that is a lower octane and perhaps out of specification, while the bottom layer is a mix of water and ethanol that will not burn. This is Phase Separation. Housekeeping at the service station is very important to prevent water con- tamination. “ Depending upon individual conditions, about 40% to 80% of the ethanol will be drawn away from the gasoline by water and will separate into two distinct layers.” “ The top layer will be a gasoline that is lower octane and perhaps out of specification, while the bottom layer is a mix of water and ethanol that will not burn.“ Phase Separation in Ethanol Blends Did You Know? In a 10% Ethanol Blend, it takes as little as 18 gallons of water in a 6,000 gallon tank to cause Phase Separation. In a 2% blend it takes only 3.6 gallons to cause Phase Separation!