Mileage Gains Using Ethanol Seen 20% Higher Than EPA SaysMark Drajem
A tweak to an automobile’s engine software can improve by as much as 20 percent the estimated fuel efficiency when using gasoline with ethanol or methanol, according to a non-profit group pushing gasoline alternatives.
A Fuel Freedom Foundation study showed that setting the engine to run at an optimal setting for the higher octane in so-called alcohol fuels can cut the greenhouse gases emitted on average by 17 percent to 20 percent, making it better for the environment than estimated by independent analysts and the Environmental Protection Agency.
“Alcohol fuels are not getting a fair treatment,” Eyal Aronoff, a founder of the non-profit group and co-author of the study to be released soon, said in an interview. With the correct analysis, “the greenhouse-gas emissions look really, really appealing.”
Fuel Freedom is an independent non-profit based in Irvine, California, that doesn’t have financial ties to the ethanol industry. It advocates for policies to build a distribution system for alternatives to gasoline in order to cut drivers’ costs and spur economic growth.
The EPA bases its mileage estimates on the best available science, and if a new, credible study contains relevant information, the agency will consider its findings, according to a statement in response to questions about Aronoff’s study.
Under the Renewable Fuel Standard, passed by Congress in 2007, refiners such as Exxon Mobil Corp. must use a certain amount of renewable fuel each year, with the contribution tied to their share of the fuel market. The EPA and renewable-fuel producers say it spurs production of domestic fuels and cuts greenhouse-gas emissions by reducing use of gasoline or diesel.
The energy content in a gallon of pure ethanol is about 33 percent less than that in gasoline, according to the U.S. Energy Information Administration.
In analyses performed by the EPA to analyze the emissions for corn-based ethanol, the greenhouse-gas emissions are close to that of gasoline, or maybe greater depending on how the fuel is made and what assumptions are used.
“EPA’s conclusion was that there were opportunities for ethanol from an efficient facility to be a little bit cleaner than gasoline,” Jeremy Martin, an analyst on biofuels at the Union of Concerned Scientists in Cambridge, Massachusetts.
Emissions estimates must account for any reductions tied to carbon that’s absorbed by cropland and forests, according to Martin’s group. Environmental groups such as the Natural Resources Defense Council, citing the role of crops and forests, question the benefit of substituting corn-based ethanol for gasoline. Groups such as Friends of the Earth say the renewable fuel mandate should be scrapped.
Refiners are also fighting the renewable fuels standard, and the American Petroleum Institute has argued to Congress that ethanol provides no greenhouse-gas benefit to gasoline.
“It’s true that you can offset the energy-content loss with a higher-compression engine, but it’s not because of anything unique to ethanol,” Patrick Kelly, senior policy adviser at the American Petroleum Institute, said in an interview. “It’s the octane that ethanol delivers.”
Aronoff, who co-founded Quest Software Inc. before it was sold to Dell Inc., says that’s the point. Alcohol fuels are a way to cheaply deliver higher octane, and adjusting engines to run most efficiently when using those fuel blends could boost efficiency and led to more miles per gallon.
“The energy content of fuel is what it is,” Aronoff said in an interview. “But if you program the car to run on methanol, you can get better conversion efficiency.”