A yellow and black Butler Cat Challenger M5 tractor is not an uncommon sight on the North Dakota State University campus, after all this is a land-grant institution, an agricultural university. This tractor, however, is sitting in an unusual place -- behind Dolve Hall and the mechanical engineering department. On the front end of the tractor perches a strange looking fiberglass tank about the size of a water-cooler jug tipped on its side.
A sticker on that tank proclaims, H2 NDSU. On the periodic table, H is of course hydrogen, and, as far as Robert Pieri knows, this tractor is the first agricultural-use vehicle to be converted to run, at least in part, on hydrogen.
Pieri and his team of mechanical and electrical engineering students haven't reinvented the wheel in this, he says. What they have done is used the hydrogen conversion technology available for cars and trucks and retrofitted the tractor as part of a Wind to Hydrogen project of the energy company, Basin Electric.
While two members of that team, Austin Decker and Aaron Zuther, lift the hood to examine the engine, Pieri, tall, grey, bespectacled, serious, checks this correspondent's credentials before beginning a lecture that covers the origins and development of the internal combustion and diesel engines, and weaves in such events as the first oil well drilled in western Pennsylvania by Edwin Drake in 1859 and the oil embargo of 1973.
The way Pieri sees it, the Wind to Hydrogen project is a step toward bringing the modern farmer back to a self-sufficiency last experienced in farm country in the 19th and early 20th centuries. Modern wind generators, he explains, have a very small footprint -- 100 by 100 feet. Each windmill can be placed 1,000 feet apart in a line, and each will generate three megawatts of power.
What if, Pieri asks rhetorically, a farmer has a canola field, which can be used as a bio-diesel fuel, bordered by windmills producing energy that can be stored as hydrogen and used along with the canola as fuel for the farmer's vehicles?
The answer is that it doesn't negatively affect the environment and is not tying the farmer to fuels coming out of the desert halfway around the world. The science behind it, he admits, can put most anyone to sleep. But what can be understood, and what is exciting about the project, he stresses, is that chance to bring self-sufficiency back into farming through bio-fuels and wind farming.
NDSU's involvement in the project is in its second stage. The first stage was basically to prove that a tractor could burn hydrogen and not blow the top of the engine off. The second stage, Pieri says, is to experiment with the hydrogen to diesel ratio being injected into the cylinders.
Here is some of the science: hydrogen burns readily in a spark-ignition engine, but a diesel engine's ignition comes from compression. The self-ignition point for hydrogen is higher than that of diesel fuel. Pieri pauses and calls to Decker, his mechanical engineering student: "What are the numbers for the self-ignition points for hydrogen and diesel?" Decker, looking up from under his red ball cap, gives the answer promptly -- "550 degrees centigrade to around 400 degrees."
Pieri smiles. To have a diesel engine run solely on hydrogen, he continues, the cylinders would need to be almost twice as long as those in a conventional engine in order to compress the hydrogen enough to self ignite. Which is why this conversion will always need to have a ratio of diesel along with the hydrogen to run, it is needed to ignite the hydrogen gas.
Right now that mix is more diesel than hydrogen, but Pieri and his students hope to reverse that to more hydrogen than diesel. Just what is the right ratio, or the ratio that will use the least amount of diesel, is what they will be experimenting with.
Zuther, the electrical engineering member of the team, says that he signed on to the project because he is interested in the future of alternative fuels and perhaps a career in the field. Currently the flow of hydrogen into the tractor's intake manifold is being regulated manually, he explains. One of his contributions to the project will be to change that flow regulator over to an automatic control that regulates the amount of hydrogen going into the fuel ration depending on engine speed.
Decker adds that ultimately the idea is to have the tractor retrofitted so that it can run on plain diesel, bio-diesel, or hydrogen, automatically regulating the needed flow and ratio of each fuel all with a flip of a switch. The hope is that eventually the technology would be sold as a dealer installed option.
But, Pieri is quick to add, that it is quite a way down the road. And once this project is over, NDSU mechanical engineering students will remove all the retrofitting and return the tractor in its original state to Butler Machinery.
The tractor is only one part of NDSU's involvement in the Wind to Hydrogen project. NDSU's North Central Research Extension Center south of Minot is where Basin Electric is housing its electrolyzer, the machine that separates the hydrogen from oxygen in water and then stores it. The electrolyzer was brought there by Hydrogenics, a company out of Belgium.
Jay Fisher, director of the North Central Research Extension Center, characterizes the project as "cutting edge" and "in its early research and development stages." He has been driving one of three Chevy Silverado pickups converted to hydrogen that are also part of the project. Currently Fisher's pickup, retrofitted from a gas engine so that it runs entirely on hydrogen, is in Arizona being turbo-charged.
To say that Fisher is looking forward to getting that pickup back is an understatement. He has to be one of the few drivers in this country, or anywhere else, who can fill up his tank with hydrogen at his own place (the research extension center) and hit the road or the fields. He explains that this summer, running solely on hydrogen, they found the Chevys to be a little lacking in power. The turbo-charging should fix that. "I want to get my hands back on it and see how it performs," he says.
Of course hydrogen is just one of the alternative fuels that NDSU is studying. The research extension center is also looking at canola and switchgrass biofuels. You look at this, says Fisher, and it's like looking at the first light bulb. All you can really say is, "Wow."