Agriculture has big role in fuel supply

It's not unrealistic to assume that by 2025, agriculture will be supplying as much as 35 percent of the U.S. energy supply, says David Bransby, an Auburn University professor of agronomy and soils and a nationally recognized authority on biofuel alternatives. Bransby spoke at the recent Alabama Agriculture Energy Conference held in Auburn.

“The United States accounts for 25 percent of the global consumption of oil, but we own only 3 percent, making us critically vulnerable,” says Bransby. “We import more than 60 percent of what we use, and 15 percent of that comes from the unstable Middle East. It's not possible to replace that 60 percent, but it is possible to replace that 15 percent.”

Biofuels won't solve these problems completely, but they certainly can help, he says. “If the recent hurricanes aren't a ‘wake-up call,’ then I don't know what it'll take. It'll fall back on us down here, and if we have to do it without Washington, then we'll do it. We have to do something. Rural America will respond a heck of a lot faster than Washington,” says Bransby.

In addition to the hurricanes of this past season, several other developments have occurred this year in the arena of energy, he says. “There have been several new reports on bioenergy and several new emerging technologies. We've also had an energy bill and an election. In addition, consumers have seen very sharp rises in the costs of all fossil fuels — not just oil but also natural gas and coal.”

Oil, coal and natural gas all are fossil fuels, says Bransby. “The term ‘natural gas’ is a little misleading — it's not natural at all — it's a fossil fuel. We are burning it, and taking carbon out of the ground and putting it into the atmosphere. We're aggravating the risks associated with global warming,” he says.

All fossil fuels are finite, and their use is not sustainable, he adds. In addition, all fossil fuels contribute to increased greenhouse gasses and to the risk of climate change, he says. “And all of these fuels are subsidized in some way, and that's one of our toughest barriers to address.”

Experts estimate, says Bransby, that the world is very close to the point to where oil demand equals supply, after which time the price will increase sharply. “A lot of people say we're already at that point. This makes us vulnerable. The hurricanes of this year have demonstrated a couple of things. First, that global climate change is real, and I hope that gets through to Washington. They also show how vulnerable we've become from an energy standpoint.

“But it's not just the hurricanes. We've also seen fuel price hikes, but they're very different from the ones we saw in the 1970s. At that time, prices went up and came back down. Now, they will come down some, but they won't come down permanently or for a very long period of time. In the 1970s, we didn't have the rapidly expanding economies of India and China, and this demand isn't going away. In fact, it'll become more intense. We won't likely see gas again at $2 per gallon.”

Some people already are responding to this situation, he says, and it would be easier to do so with help from the U.S. government.

A study released this year by the USDA and the U.S. Department of Energy looked at the feasibility of the United States supplying 1 billion tons of biomass for energy uses, says Bransby.

“If we can do that on a national scale, we could replace 30 percent of the oil we're importing into this country. From forest resources, we can produce 368 million tons of biomass, and from agriculture resources, we can produce almost 1 billion. That's about 1.3 billion tons, and their estimates are conservative ones,” he says.

Studies show that Alabama already has enough biomass to supply all of its residential energy needs, says Bransby.

“We have crop residue in the fields and at processing plants. Although corn grain is pretty much all consumed, we have the stovers that are not being used. We have about ½ million acres of cotton stalks that are going back into the soil. We need to put some of it back, but not necessarily all of it. Cotton gin trash also is piled up at cotton gins, and it could be used. Peanut hulls also are a great feed stock.

“In addition, we can grow energy crops such as grass and trees. There's a lot of energy in perennial grasses. Across the Southeast, we grow 10 million acres each of bahiagrass and bermudagrass. We have 1 million acres of bahiagrass in the southern part of Alabama, and we have more than one half million acres of bermudagrass in the state. At the moment, it's being used for livestock. But if a fair market was developed, a lot of it would be diverted to energy.”

There also are grasses that can be rotated with existing traditional crops, in addition to animal waste, he says. “We generate more than 1.5 million tons of poultry litter each year in Alabama, and we're looking at using that as a source of energy. And we shouldn't forget about trying to grow the grain and starch crops for biodiesel. Not just from existing crops, like soybeans, but other crops that would be even better, including canola and castor bean.”

Some progress in being made in the drive towards developing biofuels, says Bransby. “Interest is strong, especially given the cost of fossil fuels. The new energy bill is a step in the right direction, but it's hopelessly inadequate. We need more than what's in that bill.”

Current ethanol technologies, he explains, include acid hydrolysis and enzyme hydrolysis followed by fermentation. “These are the old technologies, and they are the ones supported and funded by the government. Their efficiency is 60 gallons per ton of biomass and 60 to 80 gallons per ton of biomass, respectively.”

The two new technologies, notes Bransby, are owned by small companies. Their efficiencies are up to 100 gallons per ton of biomass and 90 to 130 gallons per ton. One of these involves gasification on the front end and fermentation of the gas by bacteria to ethanol. The other one involves gasification by catalytic conversion.

This technology, he says, isn't so far fetched in other countries. “Other countries are far ahead of us. Brazil produces 30 percent of its transportation fuel as ethanol. The flexible-fuel vehicles that use the ethanol come from the United States. They're using our technology to get ahead of us. Europe is ahead in terms of wind energy and incentives for biomass-powered electricity. They are ahead of us because of government incentives.”

Americans shouldn't think of government incentives as a cost to the taxpayer, says Bransby. “It has been shown over and over again that the returns from such incentives exceed their cost. Our next chance for policy change is the farm bill. What needs to be done for commercialization? Policy is more important than technology. Technologies already are out there, but they still need to be improved.

At the federal level, funding and incentives for commercial plants for emerging technologies would help us enormously, he says. “The federal government typically will take funding for new technologies up to a pilot-scale plant, and then they'll say you're on your own as far as getting the commercial plant up and running. That last step is very difficult, and the federal government needs to fund it. Our policy is lacking because smaller companies can't afford to do it themselves.

But none of this can be accomplished without education and information distribution, says Bransby.

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