Straight canola oil can pack the same power as diesel fuelDate posted: February 24, 2004
Don't try this approach at home folks, at least not without professional advice. But, using canola oil as fuel is an economical and sustainable farming practice worth some consideration.
What do an older farm tractor, a Volkswagen van, and a deep fryer at a local fast food restaurant have in common? If you made a wild guess that they can all run on canola oil, you'd be right.
As far out as it sounds, some diesel engines can be adapted to run on straight vegetable oil (SVO) fuel. No ethanol, no blending with other fuel additives, just straight out-of-the seed oil. Even used canola oil, which restaurants pitch in a rendering tank to be recycled, will power specially-modified diesel engines just as well as commercial diesel fuel that retails for 50 to 60 cents a litre.
So why isn't everyone doing this? Simply, it's not a perfect science yet. The theory does actually work in practice, however. Alberta Agriculture, Food and Rural Development's (AAFRD) AgTech Centre has modified a John Deere 3130 two-wheel drive tractor to run on canola oil. And consultant Edward Beggs, with the Westbank, B.C.-based Neoteric Biofuels Inc., has put more than 10,000 kilometres on his own 1988 Volkswagen van, all powered by Prairie-grown canola oil, at least some of it cold-pressed in the cargo area of the van as he travels around the country. He says there are dozens of farm and urban-based vehicles in North America running solely on vegetable oil.
"We don't want people to think they can start using new or used canola oil in all diesel engines," says Beggs, whose company markets SVO conversion kits. "But, it is technology being studied here and elsewhere in the world, that well suits sustainable farming practices. It's technology people should be aware of."
That's how the AgTech Centre views the idea too. The Lethbridge-based centre worked with Beggs to modify the older diesel farm tractor for demonstration purposes. They continue to monitor the tractor's operation on SVO fuel. "It may not be technology that is immediately adopted, but it may have applications in certain situations," says Kelly Lund, an energy specialist with the AAFRD Agricultural Engineering Branch, based in Red Deer.
Don't plan on the technology to power a modern a four-wheel drive tractor during seeding season this year. But, any producers with an older diesel tractor, or passenger vehicles with suitable diesel engines, could look at adapting their engines to SVO fuel. And if they can get free used cooking oil from a local restaurant it makes for economical transportation. The used oil needs to be properly filtered to remove all particles, but it can work just as well as new oil.
Most suited engines
Diesel engines most suited to SVO fuel include older indirect injection engines manufactured for some farm trucks and passenger vehicles from the early 1970s through to the mid-'90s. Some of the modern TDI (turbo direct injection) engines also have potential to operate on SVO fuel. In fact, in Germany, single tank conversion kits are available to allow for the use of vegetable oil in Volkswagen TDI engines. Beggs does not have a kit available for modern TDI engines, but it is something the company is looking at. Some classic direct injection systems with mechanical fuel pumps will also work on SVO. There are several exceptions, so a professional needs to be consulted on engine suitability.
Most farm tractors, even the older models, have direct injection engines. They will run on SVO, as the AgTech Centre's John Deere demonstrates. And again, in Germany, as this technology is being refined, the government has assisted with the conversion of 100 new Deutz tractors all to be run on new, cold-pressed rapeseed oil. Beggs says ideally, diesel engines should have some modification. Otherwise, SVO used directly from the fuel tank can cause injectors to develop a carbon build up which affects injector performance.
The key to making straight canola oil work as a fuel in diesel engines is in viscosity. Even summer-temperature SVO is too thick to provide optimum engine performance. The oil needs to be heated, and not just a little. The objective is to heat the oil to at least 70 C. Heating is a large role of the two-tank conversion kit Beggs has developed and uses to adapt the fuel system to diesel engines. The cost of the complete conversion kit, including cold weather accessories for Canadian climate, is about $1,200.
The basic process
Here's how it works. In a two-tank system, one tank holds straight new or used vegetable oil, while the other holds diesel fuel. The SVO fuel line has a specially developed in-line heating element, which warms the oil to about 70 C. The cold engine is started on diesel fuel, but once the engine and fuel are warm, the operator switches the engine to run on SVO. To shut down the vehicle, reverse the process. Switch from SVO fuel to diesel for a few minutes to purge the fuel lines of SVO and then turn off the engine. A new feature even includes a buzzer that reminds a forgetful operator if they've missed the purging step. The buzzer sounds if the engine is shut down on vegetable oil.
Reducing vegetable oil viscosity and being able to purge the system with diesel is the best bet to maintain a clean running system, says Beggs. However, he notes examples of direct injection diesel tractors operating on SVO in the fuel tank (only one tank with no heating) and they've run virtually trouble-free for years. "It can be done, but we feel for our climate the two-tank system is the best option," he says.
A European study completed last year which evaluated the use of SVO fuels in direct injection engines reported "generally all measured operating characteristics power, torque, fuel consumption and efficiency prove that when using these novel fuels there are only slight power and consumption disadvantages in comparison to diesel fuel."
Long range scenario
"Biofuels such as straight vegetable oil aren't suitable in all engines, in all circumstances and in all operations," says Beggs. "But I do see them filling a niche in farm fuel needs."
The SVO fuels may have the best fit in regional farm-based co-operatives, he says. A group of producers in an area could buy equipment for cold-pressing canola to extract their own oil. More of these co-operatives are being organized in Canada and the U.S. Even green seed and lower quality canola often processed just for meal could be used for SVO. "The group could use the oil to operate SVO engines and either feed or sell the canola meal byproduct," says Beggs. The meal from the cold-press system, containing about eight percent canola oil, has been found to be more palatable and nutritious than press cake from the conventional solvent-extraction canola crushing process.
The cold-press systems can be expanded on a modular basis, as needed, says Beggs. "One operation in the U.S. uses cold press just to make meal pellets for their elk herd," he adds. "For them the oil is the byproduct they don't use. The economics of cold-pressing need to include finding value-added uses for the pellets and oil together."
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