The U.S. farm industry uses 4 billion to 5 billion gallons of diesel fuel per year — for farm equipment and transportation. If the dreams of researchers at the USDA Peanut Research Lab in Camilla, Ga., come true, peanut farmers could replace millions of gallons with biodiesel from peanut oil.

Peanut farmers in the United States historically produce approximately 4 billion pounds of peanuts per year. If every peanut grower produced 10 percent of his crop in low-input, high-yielding, high-oil-content peanuts, somewhere in the neighborhood of 200 million gallons of peanut biodiesel could be available to American farmers for about $1.60 per gallon.



Research at the University of Georgia (UG) has pegged peanut biodiesel at 123 gallons per acre, based on state average yields, which are 500 to 600 pounds per acre higher than the low-input peanuts in the USDA test.


Currently, the primary oil used in the United States to make biodiesel fuel is soy oil, which regularly produces 50 gallons per acre, based on average national soybean yield per acre. Palm oil, canola oil, even used cooking oil are other sources for biodiesel.

The major stumbling block to converting peanut oil to biodiesel is the current high price of peanut oil. To be competitive with other biodiesel oil sources, Faircloth contends, growers would need to look at a whole different way of growing peanuts and grow this crop separate from edible peanuts.



In tests in his UG lab, Geller says, peanut biodiesel is less toxic to the atmosphere and has a cleaning effect on diesel engines. He says peanut diesel can gel in the engine at temperatures as high as 50 degrees F, but the problem is easily fixed, and not likely to be a limiting factor in commercial use.

Peanuts and biodiesel go way back — to the beginning of diesel engines. German scientist Rudolph Diesel received a patent for his engine design in 1893. At the 1900 World's Fair, Diesel demonstrated his new engine powered by peanut biodiesel. Diesel noted at the World Fair demonstration that his vision was that fuel for his engine would be grown in the area where the diesel powered vehicles would be used.







A rye cover crop was planted to help with weed control on peanuts planted in early June. Glyphosate, Prowl and paraquat constituted premerge and early season weed control,followed by a half rate Cadre and 2,4-DB later in the season.

The researchers added gypsum and due to an extremely dry planting season in 2006, and added Lorsban for insect control.

Irrigated peanuts in the combined tests yielded 2,200 pounds per acre. However, Faircloth points out, the peanuts were under so much stress, irrigation didn't help much, considering the dryland peanuts still averaged over 2,000 pounds per acre, over all varieties at all locations.

Georganic under irrigated conditions made nearly 3,000 pounds per acre using the minimal input system. Georgia 03-L and Georgia 04-S, a Spanish type variety, did well in the test. Georgia Green, the most popular runner variety currently grown in the Southeast, was in the middle of the pack at about a ton per acre.

In 2006, the oil content in the varieties tested ranged from a high of 49 percent to less than 45 percent.

Faircloth points out that in 2005 many of these same varieties produced 5 percent more oil due to better growing conditions, compared to 2006.




The bottom line, Faircloth emphasizes, is how much it costs to produce a gallon of peanut biodiesel with these minimum input peanuts. Under irrigation, Georganic was the most efficient at $1.75 per gallon. The average cost from all varieties was $2.38 per gallon.

Of dryland peanuts, GA-03L was the most cost-efficient variety at $2 per gallon. In some varieties, yields were so low that the cost per gallon topped $8. This is a clear indication, Faircloth says, that growers need to be careful to choose the right varieties and right production system to get maximum gallons per acre.

In a real-world situation, Faircloth says, peanut oil will most likely be used in a 50/50 blend with No. 2 diesel fuel.

With a government subsidy of 50 cents per gallon and petroleum diesel fuel at $2.45 per gallon and peanut diesel at $1.75, the total cost of a gallon of blended diesel would be $1.60 per gallon, using the low-input production system used in the USDA tests.

Even dryland peanuts, which cost $2.69 a gallon just for oil, is more than 30 cents a gallon cheaper than diesel fuel once the tax credit is applied. Faircloth points out that his equations include only a 50-cent per gallon subsidy. In some cases $1 per gallon is available.

