People don’t typically associate vegetable oil and construction equipment, but that’s exactly what the folks at Penn State University and Groff Tractor are doing.
Penn State’s College of Agricultural Sciences’ Farm Operations and Services is operating a Case 621E wheel loader running on vegetable oil.
“The purpose of this whole project was to take a look at what happens to an engine that is run on straight vegetable oil,” Doug Schaufler, senior project associate of Farm Operations and Services at The Pennsylvania State University explained.
The College of Agricultural Sciences’ Farm Operations and Services, a unit within the College of Agricultural Science, handles a lot of animal manure and feed stocks for the animals, and as a result operates a great deal of equipment. Most of the equipment it uses is farm equipment, including front-end loaders and on-highway dump trucks.
“Probably about five years ago Case was interested in using biodiesel in engines and 100 percent biodiesel. Because Case is in Pennsylvania, Penn State ended up with two or three New Holland tractors to run on straight B100 biodiesel fuel, and that kind of partnership led into them being interested in using straight vegetable oil. We ended up with two vehicles that could use straight vegetable oil as a part of their fuel for long term. [Case] was interested in getting some hours on those machines and that’s how we got involved in using straight vegetable oil,” Schaufler continued.
The two vehicles at Penn State — a Case 621E and a New Holland 7060 farm tractor — both have Fiat engines and are set up with two tank systems made by the European company Elsbett. A smaller tank is added to the machine for holding petroleum diesel fuel while the main fuel tank holds the straight vegetable oil.
“The machines are set up in such a way that when the load on the machine reaches about 25 percent of the rated engine load, then the machine switches it over to using straight vegetable oil. When the machine backs off and the load lightens and comes back to less than 25 percent of the rated engine load, the machine switches over to the petroleum diesel fuel and pulls fuel from that tank. So when the machine is being worked hard it runs on straight vegetable oil; and when it is not being worked as hard and engine temperatures are not as high inside the cylinders it runs on petroleum diesel fuel. So it kind of bounces back and forth between the two.”
According to Schaufler, there are still a lot of questions on using straight vegetable oils as a fuel in a diesel engine.
“Vegetable oil is thicker than a diesel fuel so when it comes out of the injector it behaves differently, generally the droplets aren’t as small as petroleum diesel fuel or even biodiesel fuel and as a result it burns in a different sort of way inside of the cylinders. The belief is that when the temperature is higher inside the cylinders the droplets will burn better, or burn more effectively, more cleanly, and won’t leave deposits that are found with engines that run on lower temperatures on the vegetable oil,” he said.
Groff Tractor and Case have been supporting the machine.
“Regular oil change intervals are half of what it would be otherwise. We have been taking oil samples every 100 hours to have those analyzed, mostly to make sure that the vegetable oil is not making its way into the crank case, because that is one of the problems with vegetable oil. It doesn’t all burn in the cylinders, at low temperatures especially, it ends up washing down the walls and ending up in the crank case and the crank case oil level actually can go up sometimes. We haven’t seen that at all,” said Schaufler.
Schaufler warned, however, that there could be some negatives associated with using vegetable oil.
“It does take some extra care and it does take extra time and that there are other things that are going to come up if you’re using it and there is no way around it,” he cautioned.
But he’s not dismissing the project.
“As the price of diesel fuel goes up there is a lot more interest in alternative fuels of course, and we are no different than anybody else in that respect. I think we’re doing this primarily to gain some more understanding of how the whole process works and as part of Penn State’s objective of outreach in education it gives us a sounder footing for answering questions that come up. We’ll have good ideas of how much fuel goes through and what the fuel is and that sort of thing,” he concluded.
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