Two major energy-related research projects just underway at SIUC will contribute to fuel efficiency and a cleaner environment.

The first aims to build and commercialize a lower-emission, more powerful, more fuel-sparing diesel engine based on a mono-valve design. Engines now have two or four valves to take air in and out of each cylinder; the work at SIUC will fine-tune the use of a single valve for that purpose.

Peoria-based Caterpillar Inc. has donated two U.S. patents, several foreign patents, and $85,000 in associated funds to support the project. The timing of the research could not be better, since the Bush administration recently approved new rules to cut diesel-powered machine emissions by 90 percent over the next 26 years by combining new diesel engine technologies with reduced sulfur content in diesel fuel.

Suri Rajan, a professor of mechanical engineering and energy processes who is leading the project, says a mono-valve engine design could offer several advantages, including continuous maximum operating efficiency at all engine speeds. He anticipates that mono-valve engines will be smaller and lighter but deliver a faster response.

Rajan expects that designing, building, and testing a prototype will take a couple of years. That includes time to develop various mechanical components such as controls to make engines reach peak performance.

Undergraduate and graduate students will participate in the research and development project, and the manufacture of the prototype engine will take place in the mechanical engineering department's fabrication shop and engine laboratory.

If the prototype is successful, Rajan estimates it may be another few years before the engine could be commercially available. The technology could ultimately have applications for large trucks and other diesel machinery, such as road graders, farm equipment, and locomotives. While Caterpillar is most interested in four-stroke diesel engine applications, the patent rights also cover two- and four-stroke gasoline engines, which power everything from small lawn mowers to automobiles.

Meanwhile, a $369,446 grant from the U.S. Department of Energy is funding a second new energy-related project, this one on improving solid oxide fuel cells.

Fuel cells are electrochemical devices that convert a fuel, such as hydrogen, directly into electricity. They'll be part of our energy future because they're clean, fuel-efficient, and quiet.

So-called solid oxide fuel cells offer a key advantage over other types: they can run on any hydrocarbon fuel, from pure hydrogen to gasified coal. Unfortunately, they operate at temperatures around 1000°C. For use in vehicles, rather than just power plants, they need to run cooler.

Engineers now are developing solid oxide fuel cells that can operate at 650 to 800°C , an acceptable range for engines. But the new cells, made with new materials, will require new interconnects--the components that link individual fuel cells into stacks in order to boost power levels.

That's where the SIUC research comes in. Rasit Koc, a professor in mechanical engineering and energy processes, previously has developed interconnects for standard solid oxide fuel cells. For the new generation of fuel cells, he is now developing interconnects using titanium carbideÐbased composite materials.

An expert on fabricating advanced ceramic materials, Koc patented a process in 1995 for making very-high-quality titanium carbide powder at low cost. He'll combine this ceramic with other materials to make the new composite interconnects.

Titanium carbide fits the bill because it is highly conductive yet durable under harsh operating conditions, such as high heat and oxidation. That combination is hard to find, says Koc.

The project is a collaborative effort with David Carter of Argonne National Laboratory. Koc will develop and test the composite ceramic materials under simulated conditions at SIUC. The most promising materials will be tested at Argonne in actual fuel cells, then fine-tuned back at SIUC.

The research grant comes through DOE's Solid State Energy Conversion Alliance program, whose goal is to develop and commercialize affordable solid oxide fuel cells for transportation applications by 2010.

--by Pete Rosenbery, Media & Communication Resources; Marilyn Davis, ed.