Published on 06/29/06

Scientists studying ways to put biomass to work

By Brad Haire
University of Georgia

If you know how to do it, you can turn a handful of wood into enough fuel to power a small car about 1.5 miles, says a University of Georgia researcher.

Wood chips, sawdust or agricultural waste are examples of biomass. Hydrocarbons, such as coal and oil, and carbohydrates, found in biomass, are about the same chemically, said K.C. Das, an engineering professor with the UGA College of Agricultural and Environmental Sciences.

The biorefinery process is similar to refining crude oil. It's a way of turning biomass into products like fuel, char and chemicals that can be used to make a product like plastic.

"What we're doing is looking at various sorts of biomass available and how to use it in the most optimum manner," said Das, who also coordinates the UGA Biorefining and Carbon Cycling Program.

Energy is all around, Das says. There's solar, hydro and wind energy, for example. Energy is also in biomass.

If you've ever thrown a stick onto a fire to keep it burning, you've seen biomass energy at work. But there's more inside waiting to be unlocked.

"By taking a biorefinery approach," Das said, "we're looking at making systems that are sustainable and utilizing as much of the biomass as possible."

One way to do this is through pyrolysis, which uses high heat. Simply put, if you took a handful of wood pellets and heated them to 800 degrees Fahrenheit in the absence of oxygen, you'd get oil, gas and carbon char, the remains of the wood.

You could stop there. But you could go further and get more from the wood. Ratchet up the heat to the oil and gas to 1,475 degrees and throw in steam and a catalyst like nickel and you can capture hydrogen for fuel cells.

The common way to make hydrogen now is to use natural gas, which isn't renewable. The natural gas way also releases greenhouse gases, believed to cause global warming. Pyrolysis doesn't create any new greenhouse gases.

There are some hitches, Das said. The oil it produces is very reactive, making it hard to store and handle. But it can be modified to run in an engine with a few extra steps. CAES scientists are working on that, too.

From recovering chicken fat from poultry plants to finding the right feedstocks for industrial use, 25 faculty and staff members are working on 15 projects under the Biorefining and Carbon Cycling Program umbrella, which started about two years ago.

Just as gasoline prices have spiked in recent years, so has U.S. interest in biorefining technology. But it's not really new. "A lot of this technology has been sitting on the shelf in the United States for decades because crude oil was cheap," he said.

Countries such as Russia and South Africa have used biorefining techniques and products since the 1950s, he said. Brazilians have run their automobiles on ethanol refined from sugarcane since the 1970s.

"I think the average person would be surprised at what could be available through conversion technology," Das said. "It's competitive today because fossil fuel prices are going up."

Last year, CAES biorefining and hydrogen-production projects received $1.8 million in federal and state grants. The same amount is expected in 2007.

"What we're doing and what we'll continue to do is improve the technology in an effort to make it more widely available and sustainable," Das said.

It's tough to predict when products from biomass will replace those made from crude oil.

"Some of it has already begun, like bioplastics," he said. "I think within the next five to 10 years, the technology and the products will be more widely available and accepted. ... There's a lot happening now."

Brad Haire is the former news editor with the University of Georgia College of Agricultural and Environmental Sciences.