What if you could create an entirely off-the-grid power source without needing to charge batteries or emit harmful exhaust? A chemist in Tucson may have found the solution.
Dr. Dominic “Don” Gervasio is an associate professor of chemical and environmental engineering at the University of Arizona, and he has been working with hydrogen-powered fuel cells for 30 years. Previously, he worked at Case Western Reserve University, Motorola, Bellcore and Arizona State University.
A fuel cell is a device that uses the chemical energy of different fuels to cleanly and efficiently produce electricity, according to the U.S. Department of Energy. When using hydrogen as fuel, the only byproducts are heat and water.
Existing hydrogen fuel cells combine hydrogen gas with oxygen from the air to create a reaction that sends electrons through an electrical circuit, producing electricity, and water is released as exhaust.
“The ‘holy grail’ has been just to conduct ions; in this case, protons,” Gervasio said. “We’ve had some successes, and I worked on a lot of different kinds of ion conductors over my career. And when I came to Arizona, we began working on these kinds of proton-only conductors.”
Thanks to technological advances by the departments of defense and energy, Gervasio said he believes that there are practical applications for the new developments. The key to progress is in the materials used.
“These materials, they conduct protons with no need for water,” Gervasio said. “Most materials, when they conduct protons, drag water along with them, because typically you need water for proton conduction.”
This creates a lot of headaches for engineers, Gervasio said, because water can only get so hot — 100 degrees centigrade to be exact — before turning into steam.
“The way that you get rid of heat is you take it from a hot body to a cool body,” he said. “That’s the radiator in your car. And if you can operate at a higher temperature, the net result is you can make a very compact electrical power generator, because the radiator is small — just like in your car.”
A car radiator typically operates at 150 degrees. To operate closer to room temperature, the radiator would be bigger than the car, Gervasio said.
“The big advance in these new kinds of materials is that they conduct only protons, so that simplifies a lot of things, but they also operate at higher temperatures to reject waste heat in a compact device,” Gervasio said.
The takeaway from Gervasio’s extensive research and development is that it will now be possible to create smaller, lighter power sources that are more robust and reliable. This will be especially useful when it comes to hydrogen-powered fuel cell cars.
“I think that this kind of technology can make a practical fuel cell which gives what’s always been desired — that you don’t have to wait there and recharge batteries for hours before you go again,” Gervasio said.
Another big use for the new tech is in emergency and auxiliary power, such as backup generators for hospitals or an emergency grid for hurricane-prone regions.
“When there are hurricanes and storms, electrical lines go down, but gas lines are buried in the ground; they tend to survive,” Gervasio said. “This type of high-temperature fuel cell is very compatible with a hydrogen made from natural gas.”
That’s a big deal because present technology requires the hydrogen fuel to be cleaned excessively. The new fuel cells, on the other hand, are much less sensitive to contaminates that exist in hydrogen created from natural gas, a process that has existed for decades.
“The kind of reactors that make hydrogen, that’s pretty mature technology; those are called reformers,” Gervasio said. “Over 90 percent of today’s hydrogen is made from hydrocarbons like natural gas and petroleum.”
The higher-temperature fuel cells Gervasio is developing are so resistant to impurities that they may be able to use liquid hydrocarbon mixtures — methanol and water, for example — to make hydrogen within the fuel cell system itself. That means a hydrogen-powered car could use liquid fuel, which is much easier to manage and transport than pressurized gas.
“In fact, the liquid fuel you could use is windshield washer fluid,” Gervasio said. “Windshield washer fluid, especially what’s called low-temperature windshield washer fluid, is 50 percent water and 50 percent methanol, and that’s an ideal fuel to make hydrogen.”
The new developments will open up a lot of opportunities to use fuel cells in practical, everyday situations, Gervasio said.