The thick, viscous nature of raw oil can damage injectors, making for some pretty expensive repair costs
Producers often envy the extra value added to grain and livestock by processors after those products leave the farmyard. Extracting oil from a variety of oilseeds, such as canola, is one way to do the same thing right on the farm.
The raw oil can be refined into biodiesel and the meal — what’s left over after oilseeds have been through an expeller press to remove their oil content — can be sold or used on the farm as a high-protein feed supplement. The raw oil can also be burned as fuel in diesel engines even without refining it into biodiesel.
“Once you have the oil, you have to decide what to do with it,” says Rex Newkirk, director of research and business development at the Canadian International Grains Institute, which provides seminars across the Prairies on how to make biodiesel on the farm.
“The other thing you can do is burn the oil straight (in a diesel engine),” adds Newkirk. That may require making some modifications to a vehicle, he says. The thick, viscous nature of raw oil can damage injectors, making for some pretty expensive repair costs.
BLEND YOUR OWN FUEL
The way to overcome that problem is to heat the oil before it gets to the engine, reducing its viscosity. Then it can be burned as fuel. One simpler solution is to blend the raw oil into diesel in smaller concentrations, that eliminates the need for modifications. But it also minimizes the amount of raw oil that can be used.
“Generally speaking, (because) there are exceptions, a diesel can run on five to 10 per cent vegetable oil as a fuel additive without adding any external heat,” says Jasmin Hofer of Energrow, an Ontario company that provides oil-processing and vehicle-conversion equipment.
Hofer adds that anyone blending oil should keep weather conditions in mind. Concentrations should be kept low during cold temperatures. In the summer, when things warm up, the concentration can be increased.
Blending raw oil into diesel can be done without adding a second fuel tank to a vehicle or machine. But to run an engine on pure oil, a second tank must be installed to keep the raw oil and diesel separated. With a dual-tank system, the engine always starts and runs for a short time on regular diesel. When it gets up to normal operating temperature, the engine can be switched over to run on just raw oil.
During the initial warm-up period, heat from the engine’s cooling system is circulated around the oil tank to raise its temperature. After the oil warms up, the engine is switched over to run on it. By then the viscosity has been reduced allowing it to flow more easily.
“The two-tank system is the most recommended by us for running higher quantities of oil,” says Hofer. “Once (the engine is) up to temperature, you switch over to the canola oil tank. Two-tank systems have the ability to run on 80 to 100 per cent straight vegetable oil.”
Companies like Energrow make conversion kits for vehicles that include all components necessary to burn raw oil as a fuel. “A two-tank conversion consists of an additional fuel tank, heat exchanger, heated filter, heated lines or outlets and valves. Generally, conversions can range from $750 to $4,500,” says Hofer.
THE COST OF PRESSING OIL
But along with the expense of converting a vehicle is the cost of purchasing the system to produce oil in the first place. “For a complete turnkey system installed on-farm, including our mobile filtering system, a farmer would be
looking at approximately $25,000 to $35,000,” says Hofer. The price varies with the amount of automation and built-in ability to upgrade the system, increasing capacity.
After extracting the oil, producers will need a suitable place to store it until it’s used. “Oil should be stored in a cool, dry place out of the light and oxygen if possible,” says Hofer. And she notes oil extracted with an expeller press tends to be more stable than oil extracted by other systems. Oil produced by the systems Energrow sells, which include expeller presses, meets the DIN51605 European standard for fuel oil.
After pressing, the meal produced can be fed to livestock immediately; but the oil should be left long enough for the sediment to settle out, which is especially important when using it as a fuel.
While running a machine on raw canola oil may sound a little unusual to some, manufacturers are beginning to produce engines capable of taking advantage of this fuel resource. Fendt’s 820 Greentec tractor is one example (see a full Profireport on it in this issue). “Which begs the question, is it the fuel or the vehicle that needs to adapt?” comments Hofer.
But even if you are reluctant to pour raw canola oil into a new and very expensive diesel engine,
there may still be a good economic reason to start extracting it on the farm. Both it and the meal can be sold into the livestock feed market. There is also a niche demand for raw, unrefined canola oil for human consumption, although it remains relatively small.
“Some people taking the course who started down the road to make biodiesel decided to go that route (selling the oil),” notes Newkirk. “They realize, wait a minute, I can sell that oil for $850 or $900 a tonne; fuel costs less than that.”
Scott Garvey is machinery editor for Grainews.
Contact him at [email protected]