Burn hot, burn clean, by design

Author: John Monczunski

If power plants could burn coal above 1,500 degrees Celsius, experts estimate they could increase generating efficiency 10 to 15 percent. It’s not now possible because turbines made of conventional materials can’t stand the heat. At those intense temperatures parts break down and fail. Notre Dame aerospace and mechanical engineering professors John Renaud and Vikas Tomar, however, are working to find a way around this roadblock to the promised land of clean coal technology.

Renaud and Tomar are developing computer simulation tools to design new composite materials able to withstand extreme heat. Tomar, a materials scientist, models materials at the atomic level. Renaud’s expertise is design optimization. Combining their skills, the ND engineers are attempting to identify optimal material combinations for withstanding high heat.

By selectively moving atoms around, it’s possible to enhance the physical properties of the chosen materials.

“You have an almost infinite number of combinations when you design things at the atomic level, moving an atom here and there,” Renaud notes. “The optimization framework I’ve developed allows us to query all these possibilities in a very efficient fashion, to find the ones most likely to work.”

Specifically, Renaud and Tomar are looking at a material known as a “silicon carbide silicon nitride nanoceramic composite.” After the ND researchers identify potential designs able to better withstand the rigors of high heat, a colleague at the University of Washington will attempt to fabricate the material and test its properties against the predictions.

In addition to applications in power plants, the aerospace industry is interested in such high-temperature resistant materials for use in aerospace propulsion systems.

John Monczunski is an associate editor of this magazine.