URBANA, Ill. -- We all know that saturated fats are bad for humans. But how do they work in bio-fuels?

Research at the University of Illinois is showing that what's bad for humans might be good for bio-fuels.

"Bio-fuels are made from a range of different vegetables and animal fats," said Alan Hansen, a professor in agricultural and biological engineering at the U of I. "And one of the properties of a bio-fuel that determines how efficiently an engine runs is its fatty acid composition."

As it turns out, palm oil, which may be regarded as unhealthy for humans because of its abundance of saturated fatty acids, makes a good bio-fuel. But polyunsaturates, which are healthier for humans, "are not good for engines because they lower the cetane number, or the ignition quality, of the fuel dramatically," Hansen said. "So it would seem that what's good for food is not necessarily good for fuel."

Hansen is investigating the properties of different bio-fuels, he said, "because they are used in combustion modeling exercises and experiments, and we want to be able to model the combustion of these different bio-fuels as accurately as possible."

Hansen is working with researchers from the department of mechanical science and engineering to study a variety of issues related to the automotive combustion of bio-fuels. The group recently received a grant from the Department of Energy to fund the new Graduate Automotive Technology Education (GATE) Center of Excellence on Advanced Automotive Bio-fuel Combustion Engines.

Chia-Fon Lee, a professor in mechanical science and engineering, is the Center director. Lee and three colleagues in the department, Professor Dimitrios Kyritsis, Professor Emeritus Robert White, and Robert Coverdill, Senior Research Engineer, are all working on developing engines that will burn bio-fuel more efficiently.

One of the engines they use is an optical engine, said Lee.

"It has a quartz piston at the top, and a side window that allows you to look into the combustion chamber. There is also a mirror arrangement that allows you to see underneath the engine."

This type of visual access to the process allows the researchers to watch as the fuel is injected into the combustion chamber.

Even though you can see through it, said Lee, everything happens so fast that laser equipment is needed to take images that track the combustion process.

"You can see how much remains as liquid, how much turns into vapor and how much it penetrates into the combustion chamber -- all characteristics that are important to determine the combustion," said Lee.

Funding from the Department of Energy will allow Lee and Hansen to work with The GATE Center of Excellence for the next five years, and Lee says there is a possibility of an additional five years of funding.

"The GATE project has an educational component that we didn't have in the past," Lee said. "Now we are able to train talented graduate students in both mechanical and agricultural/biological issues related to automotive bio-fuel combustion. We are also conducting a GATE seminar series that presents information you can't find in the textbooks. Even the professors get a lot out of it."

Hansen concluded, "With all the interest in bio-fuels at the moment, it's a great opportunity to see how we can take advantage of the new technologies to get an engine to run on bio-fuel more efficiently."

SOURCE: University of Illinois news release.