Nov. 2, 2005
By Anita Martin
For former Exxon CEO Lee Raymond, the future looks black as Texas tea. At last summer's Reuter's Energy Summit, before his retirement, Raymond made the pessimistic prediction: "gas production has peaked, continues to decline, and will start to decline more rapidly."
American vehicles travel about 2.6 trillion miles a year and more than half our homes are heated with natural gas. Now with 60 percent of the Gulf region's oil plants closed, and gas pushing $3/gallon, most Americans agree that when it comes to fuel, the glass really is half empty -- and quickly approaching "E."
None of this worries Gerardine Botte.
Botte, a chemical engineering professor at Ohio University, may have found a fuel cell solution to the petroleum problem. The Russ College of Engineering and Technology plans to build a prototype electric car, utilizing her new method, within the next two years. According to Botte, the answer is ammonia.
The fuel cell dilemma
Although the idea of fuel cells dates back to the early 19th century, the technology has never been commercialized. Mostly because fuel cells run on hydrogen, and hydrogen is a hotheaded, slippery little devil.
"Hydrogen is the smallest, lightest element, so it's difficult to store," Botte explains. "Molecules can and will pass through the smallest holes."
Under normal conditions, hydrogen is a gas. So, to produce enough energy to equal a gallon of gasoline, you'd need enough hydrogen to fill an average dorm room.
"Then, in order to get it down to (a gallon) volume," says Russ Fahrquar, a senior chemical engineering undergraduate who researches under Botte, "you'd have to pressurize it to pressures at least 350 times higher than atmospheric pressure."
"Hydrogen is extremely volatile," adds Purusha Bonnin, an engineering master's student from Venezuela, "which makes it dangerous."
But Botte and her students didn't let details like those slow them down.
To prevent atomic escapes and explosions, hydrogen must be combined with something else for storage and transportation. Currently, methanol (CH3OH) is the preferred way to store and transport hydrogen, but Botte doesn't like the environmental implications of methanol.
"When hydrogen is taken from methanol through electrolysis," Botte says, "it releases harmful carbon dioxide." She wanted something that would not only store and transport hydrogen, but also release it without a big stink.
That's where the ammonia comes in.
"Ammonia, which consists of hydrogen and nitrogen, is dissolved in water as a liquid," Fahrquar says, "so you could fill up your car tank with ammonia liquid and from it extract hydrogen, which you can send to a fuel cell."
That's precisely what Botte and her research team have done.
Botte started her research two years ago, "from scratch." From rough sketches and tentative equations scribbled on paper, a new fuel cell technology emerged at Ohio University.
"The idea was to build an ammonia electrolytic cell," Botte says, "combined with a proton exchange membrane fuel cell."
Put simply, Botte and her research team designed a little black box that takes hydrogen "in situ", or on-site, from ammonia and sends it on to a fuel cell. This technology could some day power road vehicles or even power homes.
"The gasoline car, because it's a combustion process where carbon is involved, produces carbon dioxide, so then you have a random pollution source," Botte says. "With the ammonia, your only by-products are nitrogen and water, which are not pollutants."
In summary, Botte's little black box starts with ammonia, combines it with oxygen from the air and yields hydrogen as fuel and two byproducts: water and nitrogen, which already makes up 78 percent of the air that we breathe.
To test her idea, Botte devised a crude electrolytic cell that takes hydrogen from ammonia and uses it to power a small propeller.
"That's net power," Fahrquar says, pointing to the spinning propeller. "That proves the system works."
Botte's next step was to build a model car, about six inches long, that runs on a cup of ammonia, and take it on parade.
In Botte's laboratory, Bonnin, who worked in the oil industry before shifting to more earth-friendly alternatives, adds ammonia to the model car and sets it in motion.
This simple small-scale sedan attracted attention and support from Ohio University's 1804 Fund, the Russ College of Engineering and Technology, and the Consortium for Economics Energy and the Environment, as well as from three engineering departments: chemical, mechanical and electrical.
Total funds provide a two-year budget of $199,000. The money will be used to upgrade Botte's model car into a full-sized prototype.
Botte, along with colleagues Jim Zhu (electrical engineering) and Gregory Kremer (mechanical engineering), will work with Russ College graduate and undergraduate students. Together, they will convert an electric golf cart into an ammonia fueled vehicle, and, by Botte's calculations, a very sound investment.
"The car engine that we're trying to eventually produce is going to be 200 percent more efficient than a gasoline car," Botte says. "That means that if, with a gasoline car, you are able to run 30 miles per gallon; with the ammonia version, you could run 60.
And if that wasn't enough to excite consumers, the estimated cost of ammonia fuel may do the trick. According to Botte, if gasoline costs $2 per gallon, you would pay seven cents per mile, "but with the ammonia engine, you would only pay two cents." According to the U.S. Department of Energy, ammonia production is one of the country's largest industries. Ammonia is the fifth most abundantly produced chemical in the United States, normally for use in fertilizers.
A clean machine
The way Botte sees it; the project is a win-win situation.
"First, we provide a hands-on learning experience for undergraduate and graduate students." Botte says.
"The region benefits because we developed this technology here, in the Appalachian area. The nation benefits, because this increases demand for ammonia, of which America is one of the biggest producers in the world. And finally, we would be polluting less and providing fuel flexibility."
Botte, her colleagues and their students still have a lot of work to do before ammonia electrolytic technology enters the world market.
"Right now, we can demonstrate net power, so we know this is going to work," she says. "Now, if we can improve the technology and increase the net power, then we have a very valuable product."
Anita Martin is a writer with University Communications and Marketing.