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On-Farm Biodiesel Processing

Forty Guernsey dairy cows once drove the economy of John Williamson’s State Line Farm near Shaftsbury, Vermont. Then came falling milk prices, and in 2003, Williamson was forced to disband the herd started by his grandfather in 1936.

The void in economic diversity created by the abandoned dairy beckoned to be filled. So when a friend suggested a big leap toward growing oilseed crops and producing biodiesel on the farm, Williamson grabbed hold of the notion.

With his creation of State Line Biofuels, Williamson became the first farmer in Vermont to develop an on-farm facility for processing biodiesel from oilseed crops grown on his own farm and those of his neighbors. The growth in his enterprise into a regional hub for the custom processing of biodiesel has been supported by grants from the Bioenergy Initiative of the Vermont Sustainable Jobs Fund (VSJF). Yet, Williamson relied on his own bootstraps to get started. The hands-on beginning gave critical lessons in small-scale, on-farm production of biodiesel.

bare-bones start

His start was bare bones, at best. His friend donated a bag of Canadian canola seed, and Williamson planted 3 acres. The planting, managing, and harvesting of the oilseed presented a steep learning curve he navigated alone.

“I couldn’t find anyone else in Vermont who had grown canola,” says Williamson. “We cleaned the seed by hand using a barn fan, and we harvested the crop with an old McCormick Deering combine. We had trouble with the fine seed leaking out of any cracks there were in the combine hopper. We ended up sealing the cracks with duct tape.”

Those 3 acres yielded 2 tons of canola and drew the interest of a county agent. A $3,000 grant resulted, and Williamson used it as seed money to purchase a Swedish oil press for $9,000. 

“The press was midrange in size,” says Williamson. “It was an efficient screw-press mill of food-grade specifications. It could process 3 gallons of oil in an hour.”

The meal (or grain-like pellets) resulting from the pressing process was just as valuable as the oil. This meal provided feed for the farm’s beef cattle.

Each ton of canola yielded a third of its weight in oil.

To make biodiesel from the oil, Williamson mixed it with sodium hydroxide and alcohol. The reactor, or mixing container, was a plastic tank salvaged from the farm’s existing line of equipment.

“We had a weedeater fastened into a drum for our alcohol-lye mixer and a milk tank agitator for a fuel reactor mixer,” says Williamson. “None of this was safe, but we had very little money invested at this point.”

After mixing their first batch of 100 gallons of biodiesel, it was time to test the fuel in a tractor. “My dad was skeptical about the whole process and wanted to test it first in the oldest tractor on the farm – a Massey Ferguson 65,” says Williamson. “We put the biodiesel in that tractor, and he went out and mowed hay with it. It worked great!”

In time, Williamson processed more biodiesel, primarily from canola and sunflower oil, and he burned it in all the diesel-powered equipment needed to grow oats, oilseeds, hay, and sugar crops on his farm’s 230 acres.

“I burned the biodiesel in a diesel pickup, four tractors, and a combine. That 100 gallons of biodiesel lasted quite awhile, and it didn’t take long to make a new batch,” he says.

“We’ve done a bunch of tests since then, including mixing it with differing proportions of regular diesel fuel,” he says. “We’ve found no difference in rates of fuel consumption between diesel fuel and biodiesel.”

A benefit of the biodiesel is the nonirritating scent of the exhaust. “It’s almost a pleasant smell,” says Williamson. “If you’re burning biodiesel processed from used frying oil collected from restaurants – as we have done, as well – the exhaust takes on the smell of whatever food was fried in the oil. If it was onions, then the exhaust has a pungent onion odor.”

Lubricity is improved

Lubricity is another benefit of biodiesel. “Because biodiesel is more slippery than regular diesel fuel, it makes diesel engines run smoother,” Williamson believes. Research and personal experience taught him, too, the cold-weather drawbacks of the biofuel. “After starting an engine burning biodiesel in cold weather, the engine has a little less power until it warms up,” he says.

In Vermont’s cold winters, the biodiesel can gel. Blending the fuel half and half with diesel fuel prevents the gelling. Williamson has also found gelling not to be a problem when a biodiesel-burning machine is kept in a heated shop. “Once it’s running, the engine keeps the fuel warm,” he says.

After several years of processing biodiesel using his bare-bones system, Williamson was approached by the VSJF. “The VSJF wanted to promote the small-scale, on-farm production of biodiesel,” he says.

The ensuing grants and agency support led to the expansion of Williamson’s capacity to produce biodiesel. Between 2006 and 2008, his on-farm enterprise – State Line Biofuels – developed the processing capability to produce 250,000 gallons of biodiesel per year. Williamson built much of the facility from materials salvaged from the dairy. The total capital cost came to $135,000.

For a number of years, his business provided custom-processing services for farmers within a 30-mile radius. Williamson pressed oil from their oilseed crops and processed it into biodiesel. The farmers received both the biofuel and the meal.

drop in prices hurt

This business activity was financially feasible until the price of diesel fuel dropped, reducing the economic viability of biodiesel production. “All the farmers who were involved with us have backed off,” says Williamson. “It costs us $3.50 to produce a gallon of biodiesel. That’s not feasible when diesel fuel costs about $2 a gallon.”

Williamson continues to process biodiesel from used frying oil at a production cost of 60¢ a gallon. He remains poised to again process biodiesel from oilseed crops. “We continue to power our farm with biodiesel,” he says. “It’s important to me to remain energy independent and to provide our own source of fuel.”

cost of production

A recent study at Tennessee State University suggests that cost of production for on-farm processing of biodiesel from sunflower varies widely. The study reports a production cost ranging from $2 to $3.21 a gallon. The cost includes revenue from seed meal.

This cost range suggests that differences in crop production and processing scenarios require further study. Yet, the range leaves room for cost-effective biofuel production even when the price of diesel fuel is low.

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