John Deere showed off a canola-powered forestry harvester at the recent Green Week agricultural display in Berlin and says once some modifications were made the plant-based fuel produced the same power as conventional diesel.
The German state of Bavaria initiated the project in an effort to make forestry operations more environmentally friendly and contracted John Deere to do a 30-month research programme.
Research leader Professor Peter Pickel says modifications had to be made to the engine’s electronic control unit, changing the injection timing and pressure, and extra heating elements were added to keep the canola oil runny enough in winter.
“The engine got some extra heated tubes and hoses because in winter operation the canola oil gets like butter,” he says.
Other modifications were made to comply with exhaust emission regulations but researchers found plant-based oil has advantages over diesel in that regard.
With diesel the particulate (soot) filter that every modern vehicle is fitted with needs to be cleaned regularly and that is done with a pulse injection of diesel fuel, adding up to 3% in overall fuel consumption.
That happens automatically without any input from the driver. But plant oil burns a little hotter than diesel and produces less soot and seems to be self-cleaning, actively burning unassisted in the particulate filter.
“This leads to a self-regeneration effect in the diesel particulate filter so we don’t need to regenerate the filter,” Pickel says.
That means there’s no need for the injection of fuel to clean the filter, lowering overall fuel consumption.
“The biggest challenge was emissions and winter operation because of the butter effect but there were some effects that were positive for us.”
Originally, it was agreed that after the project the test machine would be converted back to run on diesel but so successful has the testing been that the Bavarian state government wants to keep it as it is.
“They want to have a clean machine for forest operations. If you spill some of the plant oil on the ground in the forest it does not hurt, it’s not toxic to the ground. For them, it’s an environmental issue.”
The next step is to create a multi-fuel system so machines can run on different products including diesel, biodiesel, which is plant-based but with glycerin removed to make it very similar to diesel, or plant-based fuels basically made by pressing out the oil from the seeds of crops including canola, sunflowers and soya beans.
“We want to make the engine detect the fuel in the tank and optimise automatically.”
