Plasma Combustion Technology Could Dramatically Improve Fuel Efficiency

The technology, a plasma combustion technique that applies electrical voltage to the gaseous-phase fuel stream prior to combustion-turning the fuel into a plasma-has already produced excellent results with propane. The next step, according to the research team, Don Coates, an intellectual property and industrial partnerships coordinator with the Physics and Chemistry divisions, Louis Rosocha of the Plasma Physics Group and David Platts of the Hydrodynamics and X-ray Physics Group, is to move into a new experimental phase with a working fuel injected gasoline engine.

But with no suitable engine readily available at the Laboratory, and no funding to purchase a new engine, the researchers were at an impasse. That's when Coates turned to the New Mexico vendor community. He quickly contacted Chris Tornillo at the Albuquerque branch of Cummins Rocky Mountain. "Chris recognized the value of the research almost at once," said Coates. "The Laboratory has had a wonderful working relationship with Cummins Rocky Mountain for years and so before too long he had offered to loan us, no strings attached, a brand-new Cummins generator engine that we could use for whatever research was needed -- he said we could do whatever we wanted to it -- obviously this level of generosity is pretty overwhelming."

Coates, Rosocha and Platts take delivery of the 300-pound, 5-10 horsepower, four-stroke twin cylinder engine today, delivered personally by Tornillo. "We can't wait to get started on the next set of experiments," said Coates. "We think we can drive the 'leanness,' or efficiency, of the gasoline to unheard of levels, much in the same way we did with propane."

Kerosene, propane, gasoline and diesel fuel are all hydrocarbons, all made up of the same basic chemical constituents but separated by the size of their individual molecules. The more efficient fuels, and therefore more highly refined and expensive kerosene and propane, consist of fairly small chains of carbon and hydrogen atoms, whereas the less efficient and cheaper fuels, gasoline and diesel, are made of long chains of molecules. According to Coates, when electrodes attached at the spray nozzle of a fuel injector apply enough voltage to the fuel, energetic plasma electrons from voltage-induced breakdown of the fuel cause reactive species to be created, changing the basic chemical composition as the fuel becomes a plasma.

"You put into an engine the equivalent of a 'process plant' or fuel refinery," said Coates. "The plasma unit basically acts like a 'cracker' in a refinery, cutting the long chains of hydrocarbons into bite-size parts -- the smaller the parts the better the burn -- taking cheap fuels and making them combust like expensive ones."

The three researchers also believe they can construct a device that is relatively simple, cheap and easy to retrofit to existing fuel injection systems. "The ultimate goal is driven by fuel efficiency, of course," said Coates. "But this could also have a dramatic impact on the environment, with the reduction of combustion waste products, specifically nitrogen oxide. In the coming years, new federal requirements will force internal combustion engines to be cleaner and cleaner -- this technology could be one way to achieve compliance with the regulations. And when you think of things like large jet engines running on diesel, there is a safety improvement as well; diesel will not explode like kerosene or gasoline, it's low flash-point makes it much more safe to use."

Los Alamos National Laboratory is operated by the University of California for the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy and works in partnership with NNSA's Sandia and Lawrence Livermore national laboratories to support NNSA in its mission.

Los Alamos develops and applies science and technology to ensure the safety and reliability of the U.S. nuclear deterrent; reduce the threat of weapons of mass destruction, proliferation and terrorism; and solve national problems in defense, energy, environment and infrastructure.