A recent discovery by University of Minnesota researchers could someday make ethanol from corn the preferred source of hydrogen fuel. The event marks a promising step in the evolution of America's search for renewable energy alternatives to fossil fuels.
Hydrogen-powered fuel cells
Last year, President Bush's FreedomFuel initiative earmarked $1.2 billion toward the development of fuel cell and hydrogen technology. The move helped validate the significance of fuel cells, which use a chemical reaction rather than combustion to generate electricity and heat with relatively little pollution.
With continued research, scientists believe that hydrogen-powered fuel cells could someday electrify houses, businesses and vehicles across America. If and when this dream is realized depends in part on whether technology can advance far enough to make hydrogen fuel cells a less costly energy alternative to burning fossil fuels.
One challenge has been where to get the hydrogen. Though hydrogen is the most abundant element on Earth, most of it is locked up with other elements in forms such as hydrocarbons and water. It takes a lot of energy to get significant quantities of hydrogen from water alone, so the most practical sources from which to liberate hydrogen are fossil fuels such as natural gas, diesel fuel or gasoline. But using fossil fuels as a hydrogen source removes some of the “green” appeal of fuel cells.
Hydrogen from ethanol
The University of Minnesota's discovery appears to position corn-based ethanol as an appealing alternative. Lanny Schmidt, professor of chemical engineering, headed the project along with assistants Gregg Deluga and James Salge. The team's prototype reactor was able to produce hydrogen from ethanol after two simple adjustments to a process already used to get hydrogen from methane, natural gas and gasoline.
The first step was to use an automotive fuel injector to vaporize an ethanol-water mix. The second required altering the composition of the reactor's ceramic catalyst material, a combination of the elements rhodium and cerium, for the vaporized ethanol to pass through and be converted. Schmidt says other researchers had tried similar methods but gave up because fires often developed in the reactor. Schmidt's team adjusted the process enough to avoid the fire problem.
Why turn ethanol into hydrogen rather than burn it? The answer is efficiency, Schmidt says. “Ethanol in car engines is burned at 20% efficiency because you have to remove the water first. But if you use ethanol to produce hydrogen, the efficiency is 50 to 60% because you don't need to remove the water. Hydrogen comes from the ethanol and the water.”
Wind and power
Throw wind power into the mix, and ethanol-based hydrogen becomes an even more practical energy source. The University Outreach Center in Morris, MN, is looking at ways of using wind-generated power in conjunction with fuel cells. Facility director Greg Cuomo explains that using wind power to collect hydrogen is one way to store the energy of the wind. Wind power is a key part of hydrogen economy research in Europe.
In many rural Minnesota and other Corn Belt communities, using wind and corn, two abundant and renewable resources, could create revitalized local economies. A rural-based hydrogen energy economy would create new jobs and income for local residents. At some point, each community or business might have its own fuel cell power plant, creating a distributed power network to make communities more energy independent.
Before those dreams are realized, many current conditions need to change. In addition to hydrogen energy's getting cheaper, energy derived from sources such as coal-fired generators and nuclear plants will need to get more expensive, either through scarcity of resources or government-mandated environmental assessments that attempt to place a monetary value on the cost of pollution. Such scenarios are most likely to occur decades, not years, into the future.