Alternative fuels sound like a winning proposition: reducing dependence on foreign oil, reducing the impact on the climate, and cutting down on prices at the pump have all resulted in the call to increase the proportion of renewable fuels available to users, stated Ranajit (Ron) Sahu, Ph.D, consultant for environmental and energy issues. In particular, there have been marked calls to rapidly increase the proportion of ethanol (ethyl alcohol) in gasoline. However, proponents of mid-level ethanol blends fail to properly consider the interaction of these proposed fuels with a large and extensive existing fleet of over 300 million pieces of equipment and vehicles that have to run successfully on the fuel they are given but are designed to run only on gasoline containing up to 10 percent ethanol.
According to Sahu, the current gasoline pool in the United States contains anywhere from 0 percent by volume (E0) to 10 percent by volume of ethanol (E10) depending on time of year and location. A mix of 85 percent ethanol in gasoline (E85) is also available as a motor fuel for vehicles that are capable of using the fuel. There are several efforts underway to statutorily increase the ethanol proportion to greater than 10 percent. In particular, Minnesota has targeted 20 percent ethanol in gasoline as the goal for fuel for the conventional market, and legislators in other states have attempted to mandate 30 percent and 50 percent ethanol blends.
In his “Technical Paper On The Introduction of Greater Than E10-Gasoline Blends,” Sahu indicated that some (but not all) of the changes in fuel properties due to the addition of ethanol to gasoline include:
* Change in octane number
* Change in fuel volatility (as measured through several properties, including vapor pressure, vapor-liquid ratio, and the temperature-distillation curve)
* Change in the energy density
* Change due to the oxygen content
* Effect on water solubility and phase separation
These property changes can affect performance, emissions, or both. Ethanol also may affect the fuel’s compatibility with various materials, which means it can affect the product’s durability.
Ethanol also corrodes certain metals, stated Sahu. Corrosion occurs through different mechanisms including acidic attack, galvanic activity, and chemical interaction. The first is caused by water in the fuel. Ethanol attracts and dissolves water, creating a slightly acidic solution. Unlike gasoline, ethanol alone or combined with water conducts electricity; this conductivity creates a galvanic cell that causes exposed metals to corrode. Another mechanism is direct chemical interaction with ethanol molecules on certain metals. Clearly, deterioration of materials would result in loss of function of critical engine components, resulting in fuel leaks, fires from fuel leaks, and equipment failure.
According to the Alliance for Safe and Alternative Fuels Environment (AllSAFE), blender pumps allow users to select various levels of ethanol when dispensing fuel. Yet current law only allows ethanol levels up to E10 for general purpose fuel and up to E85 for use in “flexible fuel” vehicles. However, many pumps are inadequately labeled, so consumers are often unaware that ethanol levels above 10 percent are only recommended for “flexible fuel” vehicles. AllSAFE recommends that consumers check their owner’s manual or with the manufacturer to identify the proper fuel for their vehicle or product.
The Environmental Protection Agency (EPA) recently issued an enforcement letter addressing blender pumps at retail outlets and the risks involved when using fuel blends containing more than 10 percent ethanol.
“Gasoline containing more than 10 percent ethanol may cause damage to certain emissions control devices and systems, and increased emissions from gasoline-only vehicles and engines,” the EPA letter stated. “For this reason, the Clean Air Act prohibits retail gasoline stations from selling gasoline blended with more than 10 percent ethanol for use in gasoline-only vehicles and engines.”
Kris Kiser, spokesman for AllSAFE and vice president of public affairs for the Outdoor Power Equipment Institute (OPEI), said, “The proliferation of ethanol blender pumps at retail outlets in some regions of the country pose potentially serious problems for consumers and manufacturers alike. Current labeling fails to properly inform the consumer of the potential harm that a ‘mid-level’ ethanol blend may do to an automobile, motorcycle, boat, chain saw, lawn mower, ATV, snowmobile, generator or any other engine product.”
AllSAFE points out that using blends beyond the legal E10 in vehicles not designed to handle higher ethanol levels will likely void manufacturers’ warranties and may result in serious safety risks to the user, as well as performance irregularities.
“There are currently insufficient data to permit a change in law allowing the general use of higher ethanol blends in conventional vehicles and products,” said Kiser. “Without better consumer education, retailers may face a consumer backlash by using the wrong fuel in their products.”
AllSAFE added that its members do not object to increasing the overall amount of ethanol used in the nation’s gasoline supply as long as the amount of ethanol for sale to the general public does not exceed the legal and recommended 10 percent per gallon (or 85 percent per gallon for specially designed “flexible fuel” vehicles).
“We need to be vigilant that consumers are educated about the risks of using ethanol blends above E10,” OPEI stated in a prepared release. “The fact is that when ethanol levels are raised, small engines react differently, and in a potentially hazardous way.”