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U of M researchers create ethanol-to-hydrogen energy reactor
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The U's Lanny Schmidt says the eventual application is a washing machine sized unit that uses ethanol to create hydrogen that will power an electricity creating fuel cell (MPR photo/Dan Olson)
President Bush and Congress have committed the country to lessening our dependence on fossil fuels by developing hydrogen as an alternative power source. However, most hydrogen is made from fossil fuels. Researchers at the University of Minnesota Thursday announced they've developed a way to make hydrogen from ethanol, a renewable fuel. But not everyone agrees making hydrogen from ethanol adds up. Observers say it takes a lot of energy to make ethanol.

St. Paul, Minn. — Hydrogen's proponents have painted the fuel's future in the rosiest colors. Someday soon, they say, hydrogen will fuel our cars and supply electricity for our homes and offices.

Hydrogen powered cars appear to be years, maybe even decades away. There's no safe or cost effective way to ship and store the massive quantities of hydrogen required to fuel the nation's vehicles.

The technology for hydrogen powered fuel cells that create electricity for buildings, on the other hand, is available now.

The news that University of Minnesota researchers have found a way to get hydrogen from ethanol addresses several problems.

Most hydrogen is derived from natural gas, a non-renewable fossil fuel. There's an abundant supply of natural gas, but demand is rising, and prices have more than doubled in the past six years.

Also, making hydrogen from natural gas takes a lot of energy. So much, some critics argue, the energy equation is a bust - it takes more energy to make hydrogen than the fuel delivers.

Ethanol, on the other hand, is relatively easy to make, transport and store, and it's renewable. In addition, the U researchers say, the process they've developed uses almost no additional energy to make hydrogen.

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Image Reactor separates hydrogen from ethanol

Lanny Schmidt, University of Minnesota regents professor of chemical engineering, and colleagues make hydrogen from ethanol in their fourth floor lab at the University of Minnesota's Amundson Hall.

An automotive fuel injector clicks away as ethanol is pushed through and mixed with air.

"So now we have a gas," Schmidt says, "And the catalyst is right there which I don't want to touch because it's glowing."

The catalyst is glowing because it's very hot from the chemical reaction. The catalyst is a gizmo the U researches have created using the metals rhodium and ceria. It's a white, porous plug about the thickness of a thumb. When the ethanol oxygen vapor is forced through the catalyst it strips off the hydrogen atoms.

Schmidt points to the tube carrying the hydrogen to a burner.

"That jet there is a hydrogen oxygen flame," he says. "We have to burn it because we make so much hydrogen that we really wouldn't want to vent it into the laboratory or out onto the roof."

In a real world application the hydrogen would not be burned. It would be pushed through a fuel cell to make electricity.

"The fuel cell makes electricity with perhaps twice the efficiency of a power plant and that's the big, long permanent advantage," Schmidt says.

The eventual application, Schmidt believes, is for homes, farms, lake cabins - any location that needs stand alone electrical power.

Schmidt imagines a 1 kilowatt unit about the size of a washing machine where the electricity comes from a fuel cell powered by hydrogen, derived from ethanol.

Not everyone agrees ethanol is a cost effective source of hydrogen.

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Image U Scientist Greg Deluga and grad student James Salge

Ethanol is distilled from corn. Corn is an extremely energy intensive crop requiring lots of petroleum based products for planting, fertilizing and harvesting.

University of California Davis professor Dan Sperling says the energy that goes into raising corn and making ethanol makes it less attractive than natural gas as a source for hydrogen.

"It's only if you make the ethanol from a cellulosic material with not much energy going into it that it becomes even plausible as an option for hydrogen," Sperling says.

But distilling ethanol from plant stems and other cellulose creating sources, scientists say, is a ways away. For the moment, corn is virtually the sole source.

Sperling is a member the National Academy of Sciences panel which this week delivered their evaluation of hydrogen's potential. There's a lot of potential, the report concludes. However, the report recommends the country should pay much more attention to deriving hydrogen from renewable energy sources such as wind and solar. University of Minnesota scientists acknowledge the energy required to make ethanol is substantial. But they point out making hydrogen from natural gas also takes lots of energy, and the production of natural gas, like ethanol, is generously subsidized.

The research is funded by state and federal dollars including grants from the National Science Foundation. The announcement will play well in a state with 14 ethanol plants capable of producing nearly 400 million gallons of ethanol a year. The finding is reported in this week's edition of Science. The U is seeking patents on it's process.

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