Art Cullen

Green Energy in Progress

If you are interested in getting off the oil addiction and promoting sustainable rural development, you should check out the Iowa Energy Center, associated with Iowa State University. The folks there and at ISU are doing some novel and important work in melding sound agronomy and economics with renewable energy production. Check it out at

We learned more about the center after reading a case study on producing ethanol from sweet sorghum by I.C. Anderson, a retired agronomy professor at ISU. Our interest initially was piqued by Jerry Hatfield, director of the National Soil Tilth Lab in Ames, who studied nitrogen loads into the Raccoon River.

Hatfield suggested that the high nitrogen loads were not so much a result from over-applying anhydrous ammonia in the fall, as is commonly believed. Rather, he said that nitrogen moves in the water in the spring when there is no corn crop in the ground to suck it up. Hatfield suggested that sweet sorghum would be a good early crop to plant near water because it could suck up excess nitrogen until the corn crop is planted. Hatfield also noted that sweet sorghum has great potential as an energy crop.

Various studies show that sweet sorghum offers up to twice the ethanol value as corn, and 50% more mass per acre than corn. Brazil converted about 30% of its fuel use to ethanol by growing a sugar crop, not corn.

"Sweet sorghum is the closest thing to sugar cane that we can grow here," said Norm Olson, an engineer and project manager at the Iowa Energy Center.

It gets more fascinating:

Olson notes that the sheer mass of sorghum would make it difficult to handle at a huge ethanol plant. (It's a limiting factor cited for all sorts of cellulose like switchgrass or corn stover that could be used to make ethanol.) Rather than have one huge regional ethanol plant, Olson envisions two to four biorefineries per county distilling ethanol or other biorenewables such as plastics from sweet sorghum. This is not unprecedented: We used to have two to four grain cooperatives per county. These mini-refineries could be organized by closed-end cooperatives owned by local people. That's how the ethanol and biodiesel plants were first organized. Such a plant might be 10 million gallons rather than the 100-million-gallon plants we have seen sprouting up owned by outside investors. The products then could be marketed by an existing regional distributor.

Refining sweet sorghum at the factory would leave a by-product of nitrogen, phosphorous and potash to re-fertilize the soil from whence it came, Olson says. The process also would throw off hard matter called lignin that could be incorporated back into the soil to give it structure.

Olson says that a cover crop could be planted in the early fall after the sorghum is harvested that would hold until replanting in spring.

So we have a closed-cycle system that prevents nitrogen loads to our rivers and lakes, produces more ethanol per acre, maintains soil health and provides more manufacturing activity in rural counties.

"The economics are going to favor this model," Olson says.

People will begin to realize it sooner rather than later, he believes, possibly within five years using breakthroughs in technology.

Here's another interesting, and possibly revolutionary, idea that Olson is researching: Autos can run on anhydrous ammonia.

Anhydrous is the best carrier for hydrogen. It can be produced by wind turbines and stored as ammonia, a combination of hydrogen and nitrogen. The byproduct of burning it is nitrogen, which already is abundant in the air we breathe, and purified water. The infrastructure is in place in the form of huge ammonia tanks, dispensaries and pipelines. Ammonia is safer than gasoline or most other combustibles. To make diesel engines or regular internal combustion engines more efficient, adding biodiesel or ethanol made from sweet sorghum to the mix gives the engine the extra pop it needs for performance. A business in Algona, Iowa, that makes hydrogen-powered engines for the airport industry is working on engines that will be fueled by ammonia. The main hitch with it, according to Olson, is that people outside the Midwest fear that ammonia is unsafe.

One of the drawbacks of wind energy is how to store it for still days when the wind doesn't blow. You store it in the form of ammonia. The same holds true for solar energy.

This all goes by way of saying that there are ways of improving water quality, reducing our dependence on fossil fuels, exploiting wind and solar energy fully, and revitalizing rural America in ways we have not contemplated. We need to put our shoulder behind it. We can't look at these working proposals as interesting oddities but as the foundation for our future. We need to approach the topic with a complete national dedication that eclipses Project Manhattan (the atomic bomb) or landing a man on the moon.

Work is underway for the next great leap forward. That work needs the resources that are slowly but surely shifting away from the petrochemical complex.

Art Cullen is editor of the Storm Lake (Iowa) Times. Email

From The Progressive Populist, June 1, 2007

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