Learning Goes Both Ways

Close working relationship with an undergrad spurs a passion for fuel-cell research in professor

You expect professors to introduce their undergraduate students to their own research passions, perhaps inspiring undergraduates to pursue a related field as they progress to graduate school. But how often do you hear of an undergraduate going off to grad school and inspiring his professor to follow his lead into a brand new research area?

That's what happened in the case of Shripad Revankar, a professor of nuclear engineering and director of Purdue's Multiphase and Fuel Cell Research Laboratory. His former student, Josh Walter (BSNE '00), graduated from Purdue and stayed to pursue graduate studies in nuclear engineering. While Revankar was certainly pleased that Walter stayed in Purdue Engineering due to his mentorship and encouragement, what he never expected was for Walter to come back from a summer internship during 2000 at Los Alamos National Labs with a brand new interest—and a request.

Walter had become fascinated with fuel cells during his summer at Los Alamos National Laboratories and told Revankar he wanted to focus on fuel-cell research in his graduate work. The problem for Revankar was that, as Walter's graduate advisor, he only possessed a basic grasp of fuel cells—nowhere near the background needed to properly advise him through doctoral work. And so Revankar made his choice—he would delve deeply into fuel-cell research himself.

Already possessing a background in nuclear engineering—where hydrogen, as in fuel cells, is a focal point—as well as in multiphase flow, it's not as if Revankar had to start from scratch. But much of the chemistry Revankar had to learn was completely new to him. Despite the initial learning curve, however, Revankar counts himself fortunate to be given the opportunity to expand his area of practice.

"I've become very interested in the idea of a hydrogen economy," says Revankar. "Basically that just means we would supply all of our own domestic energy needs through the use of hydrogen. It would mark a complete departure from a reliance on non-renewable carbon-based fuel sources. With a fuel cell, your only byproducts are water and heat. It's completely clean."

He points to Purdue's on-campus coal plant, which operates at about a 30–35 percent efficiency rate. "If you were to employ fuel-cell technology, the efficiency goes above 50 percent, and that's a marked improvement. Plus, you're no longer burning any coal and getting all that pollution."

Currently, however, such large-scale projects are still years away from even the planning stages. Most fuel cell applications right now tend to focus on portable devices like laptops and the power-smart backpacks used by soldiers. The simple reason: price.

"It's not mainstream enough to become a consumer commodity," Revankar says. "The supply is far too low. Right now, it costs $20–$30 to generate a kilowatt of power using a car. For a fuel cell that cost goes up to $2,000."

But that doesn't mean fuel cells haven't been used for large-scale applications—just not within the consumer world. "Space shuttles use fuel cells, because in that context, price is not the most important driver. You also see some buses being converted to fuel cells, and some cities have employed fuel cells in waste-treatment facilities to convert methane gas into electricity."

As for Revankar, he's become fully immersed in the movement and the research. "Right now I'm teaching an undergraduate course called 'Fuel-Cell Engineering', and am in the process of writing a textbook on fuel cells," he says. "I guess you can say I'm an official convert."

And all thanks to an enterprising former student who didn't want to change advisors.

-Patrick Kelly