'Omnivorous engine' hopes to run on many fuels
ARGONNE, Ill. (Sept. 5, 2008) — The “omnivorous engine” is no picky
eater. Gasoline? Down the hatch. Ethanol? Butanol? It'll slurp those up too.
The creators of the omnivorous engine, engineers at the U.S. Department of
Energy's Argonne National Laboratory, seek to fashion an engine that can
run on just about any type of spark-ignited fuel.
Research on the "omnivorous engine" was
originally supported by resources from Argonne's Laboratory-Directed
Research and Development program and is now supported by the Vehicle
Technologies Program in the Department of Energy's Office of Energy
Efficiency and Renewable Energy.
DOE's Vehicle Technologies Program is developing more energy efficient
and environmentally friendly highway transportation technologies that
will enable America to use less petroleum. The long-term aim is to develop "leapfrog" technologies
that will provide Americans with greater freedom of mobility and energy
security, while lowering costs and reducing impacts on the environment. |
Unlike regular automobile engines, which typically run solely on gasoline
or, in rare instances, on a blend of gasoline and ethanol, the omnivorous engine
would be able to run on any blend of conventional gasoline, ethanol or butanol,
another organic alcohol that scientists are beginning to consider as a potential
biofuel. Even more significantly, the omnivorous engine would use a suite
of sensors to calibrate itself so that it burns available fuel as efficiently
as possible.
Since the Ford Model T, the first car built to run on both gasoline and ethanol,
automakers have introduced a variety of these flexible-fuel vehicles, or FFVs.
Since both gasoline and ethanol engines rely on a spark plug to ignite the
air-fuel mixture, it doesn't take a lot of effort to equip an engine to burn
both kinds of fuel, according to mechanical engineer Thomas Wallner of Argonne's
Energy Systems Division.
"Just because an engine is compatible with different fuels doesn't mean
that it has the ability to run at peak efficiency regardless of the fuel mixture," Wallner
said. "That's where the benefits of the omnivorous engine lie."
According to Wallner, all single-fuel and most flex-fuel engines are typically
calibrated to run on a single, usually all-gasoline, fuel source. To calibrate
an engine, engineers and auto manufacturers typically tune the engine for several
variables, including the amount of fuel injected into the engine per cycle,
the time at which the fuel is injected and the timing of the igniting spark.
Each of these parameters will have different optimum values for different
fuel blends, Wallner said. Without an omnivorous engine, cars cannot adapt
themselves independently to other fuel concentrations and therefore cannot
maximize fuel economy.
"If you just ran on a blend of gasoline and ethanol, it wouldn't be too
difficult to find out just what proportions of each you have in your tank," Wallner
said. "But if you want to add some butanol in there, discovering how to
efficiently burn that whole medley of fuels becomes a much more challenging
task."
"The ultimate goal is not to know what's in the tank, but to have it
run as efficiently as possible on whatever comes down the fuel line," he
added. "This engine can run on pretty much any liquid fuel that can be
ignited with a spark."
Instead of examining the contents of the fuel tank, the omnivorous engine
will use a suite of different sensors to evaluate the characteristics of the
combustion inside the engine as well as its chemical signature, or ionization.
If these sensors determine that the engine is not running at peak efficiency,
the engine controller will make adjustments to several parameters, including
injection strategy and spark timing.
The proposed approach is also relatively simple and cost-effective, Wallner
said, enabling the rapid commercialization of the omnivorous engine. The
omnivorous engine will run efficiently on a wide range of liquid fuels while running
especially well on biofuels, giving the consumer an incentive to use fuels
other than gasoline.
The omnivorous engine would benefit the U.S. economy by reducing dependence
on foreign oil while increasing the demand for domestically produced biofuels. "The
American public will benefit from engines that perform better and that can
switch between a wide variety of fuels based on their availability," said Steve
McConnell, one of the principal investigators on the omnivorous engine project
at Argonne.
The omnivorous engine represents one of several new vehicle technologies in
Argonne's Center for Transportation Research, where Wallner and his colleagues
work. Research on the "omnivorous engine" was originally supported
by resources from Argonne's Laboratory-Directed Research and Development program
and is now supported by the Vehicle
Technologies Program in the Department
of Energy's Office of Energy
Efficiency and Renewable Energy.
DOE's Vehicle Technologies Program is developing
more energy efficient and environmentally friendly highway transportation
technologies that will enable America to use less petroleum. The long-term
aim is to develop "leapfrog" technologies that will provide Americans with
greater freedom of mobility and energy security, while lowering costs and reducing
impacts on the environment.
Argonne National Laboratory seeks solutions to pressing national problems in science and technology.
The nation's first national laboratory, Argonne conducts leading-edge basic
and applied scientific research in virtually every scientific discipline. Argonne
researchers work closely with researchers from hundreds of companies, universities,
and federal, state and municipal agencies to help them solve their specific
problems, advance America 's scientific leadership and prepare the nation for
a better future. With employees from more than 60 nations, Argonne is managed
by UChicago
Argonne, LLC for
the U.S.
Department of Energy's Office
of Science.
By Jared Sagoff.
For more information, please contact Angela Hardin (630/252-5501
or ahardin@anl.gov) at Argonne.
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