UMass professor works to shrink hydrogen fuel cells
Professor Dimitrios Maroudas of the University of Massachusetts chemical engineering department thinks that briefcase-sized hydrogen car batteries could be on the horizon, thanks to new research attempting to advance hydrogen’s effectiveness as a “green” energy source.
Maroudas, graduate student Andre Muniz and NASA scientist M. Meyyappan were researching carbon nanotubes – tube-shaped structures of carbon atoms which measure billionths of a meter – when they discovered that there is a certain density of nanotubes where hydrogen atoms can form bonds with carbon atoms without swelling and preventing more bonds from being formed. Less swelling in the nanotubes ultimately would mean that hydrogen could finally have a viable storage method. This in turn should lead to smaller, more effective hydrogen batteries reaching the consumer market in the coming decades.
With growing concern over the environmental impact of fossil fuels and the Obama administration’s commitment to ecologically friendly fuels and technologies, this discovery could have major implications.
“It’s [got] big promise because hydrogen’s the cleanest fuel you can imagine,” Maroudas said. “When you burn hydrogen, you get steam.”
The biggest problem with a hydrogen-based economy, Maroudas said, has always been storing the fuel. Hydrogen is the lightest element and its reactivity makes for a very good fuel. However, as Professor John McCarthy of Stanford University wrote in his online journal, “a 15-gallon automobile gasoline tank contains 90 pounds of gasoline. The corresponding hydrogen tank would be 60 gallons, but the hydrogen would weigh only 34 pounds.”
The solution discovered by Maroudas and his team may have solved this problem. Scientists realized as early as 1997 that carbon nanotubes could be used for hydrogen storage. However, they always arranged the nanotubes too densely, so that when they attached the hydrogen atoms, the tubes would swell and prevent further bonds from being formed and the maximum number of hydrogen atoms could not be attached.
What the group from UMass has done is develop a computer simulation showing that there is a certain point where the swelling cannot go on. Using this knowledge, they were able to calculate a specific optimum density of the carbon nanotubes so that they can swell to their maximum without preventing the hydrogen atoms from forming all the bonds they can.
The research has been supported by a National Science Foundation grant, as well as a Fulbright Scholarship awarded to Muniz. Maroudas believes that this work could be used to build a briefcase-sized car battery that is up to eight percent hydrogen by weight. A hydrogen car battery that miniscule could have the power to transform the way energy is used across the world, and possibly make the future a whole lot “greener.”
Matthew M. Robare can be reached at firstname.lastname@example.org.