PROVO, UTAH USA -- If you don't mind the smell of French fries coming from your exhaust pipe, and you don't mind collecting and straining restaurant grease instead of pumping fuel, burning grease in your diesel engine is for you. Not only is it pocket-book free, but it is nearly emission-free. Vegetable oil has a different chemical composition, not giving off the fumes that diesel does when it burns.
Ernest and Lohetta Griesel have been running their bus on grease since November of last year. Their transportation is also their housing -- a bus that they have converted for this purpose.
Though endowed with an ironically suitable last name, the Griesels have another kind of conversion in mind as they travel from place to place. They are called "Grandma" and "Grandpa" among the Rainbow gatherings and rock concerts they accompany as they migrate from area to area throughout the United States. Mingling non-judgmentally among Pagans and Wiccans, they serve as a sort of Christian Red Cross in an environment that is sometimes less than civilized. Since 2001, they have been offering food, clothing, and inspiration to homeless youths across the U.S. in their nomadic outreach. They converted one school bus into a roving industrial kitchen, and another into a mobile home.
"We've never had so little, and we've never been so happy," he says.
Ernest describes the conversion process of how he modified his bus' diesel engine to run on grease. Given that Rudolph Diesel designed his engine in the 1890s to run on vegetable-sourced oil in order to give farmers a financial break, it’s ironic that modern diesel engines have to be converted to use this bio-fuel. It is simple enough to tackle for anyone who is even half-way mechanically inclined.
The conversion consists of installing a separate chamber to hold the grease, then running a length of coiled copper tubing through it. The closed tubing heats the grease by feeding hot radiator fluid from the vehicle's cooling system through the bio-fuel. Once it gets above 180 degrees Fahrenheit, Griesel pulls off the side of the road and manually turns a stop-cock-like switch. This enables the engine to run on the pre-heated grease, rather than on the petroleum diesel fuel from the gas tank. It's really that simple.
"I was a little nervous when I first ran the engine on grease, but it didn't miss a beat; and it has run extremely well," he said.
Of course mounting the grease chamber will take some creativity, and caution so as to avoid a fire hazard, but it is something that most do-it-yourselfers could handle with relative ease.
The only expensive component is a marine diesel filter, which can be removed for periodic cleaning. If an electronic control were added to enable the switching from one tank to the other, pulling over to turn the switch manually would not be required.
There is one other requirement that must be carried out before putting this vegetable oil into the vehicle. The grease must be strained to remove the fried-food residues which would rapidly clog the engine.
The grease needs to be above 80 degrees Fahrenheit when it is strained. Griesel uses ten separated layers of cloth. "That is not a very pleasant process," he says. Perhaps once this concept catches on more widely, this process can be automated, and "griesel" can be made available at low cost where it is in demand.
Canadian Discovery Channel reported recently that this is already being done commercially in California. In British Columbia, where one town is operating fleets of vehicles on this vegetable fuel, a few individuals are planning to set up a straining operation in order to avoid having to import the cleaned product.
Griesel says that most restaurants are more than happy to give you their grease. They usually have to pay to have it hauled off.
"I prefer Chinese Restaurants," Griesel said. "They change the grease more frequently, so it is not as dirty."
The Griesels certainly are not the first to run a diesel engine on grease. As more people catch on, perhaps there will be no longer be any such thing as discarded grease. Instead, it will enter the market as a commodity of value, to be recycled as an inexpensive alternative to planet-depleting fossil fuels.
With solutions such as the Griesels offer, a world of peaceful coexistence with nature is not just a hope of hippies.