When Rudolph Diesel invented the engine named after him around 1900, it ran on peanut oil. Whether he was inspired by egalitarianism, safety considerations, or merely an abundance of the resource, Diesel’s choice of a vegetable oil to power machines and vehicles seems prescient now. One might even wonder how and why we came to embrace petroleum so much as an alternative fuel. It has taken only a century or so, but Diesel’s good idea has cycled back around in the form of biodiesel. And a local nonprofit is doing its part to convert the waste from scores of local restaurants into a resource that reduces our dependence on petroleum and has multiple other environmental benefits.
As an inventor, Diesel is said to have been motivated by societal concerns, specifically wanting to improve people’s ability to operate independent of large industry. Vegetable oil extraction could be done on a small scale throughout the countryside, providing home-grown fuel ready to use in engines that were changing the way people worked, traveled, and built things. The higher compression and longer duration of combustion in the diesel engine was much more efficient than steam engines and is more efficient than gasoline engines.
But somehow gasoline became the primary fuel running internal combustion engines, although Ford’s Model T could also burn ethanol. In fact, Henry Ford believed ethanol was the fuel of the future and that America would grow its own energy supply. Instead, petroleum distillates with the flash point of ethanol power most cars, and the heavier distillates mimicking vegetable oils power most diesel engines.
Meanwhile, the power of vegetable oils mostly went into food, and much of it ended up being thrown away. I don’t know how much used cooking oil has gone into landfills or down drains across the nation, but I did see waste vegetable oil being “land-applied”—plowed into the soil to be biodegraded—some 30 years ago.
That’s an unsettling thought for those who are now in the business of making biodiesel from waste vegetable oil. Craig Oetting is director of operations for Green Energy Biofuel, located at the University of Tennessee. Craig became interested in biodiesel when gasoline prices spiked after Hurricane Katrina. He and his father started making biodiesel as a hobby, and they quickly discovered that getting the “grease” was the hardest part. Much of that waste stream was going into animal feed.
When Craig decided to make this hobby his career, he met some resistance because he didn’t have formal credentials. It happened there was a new degree program in bioenergy at UT, and Craig had that degree in hand by 2012. Meanwhile, the UT-affiliated nonprofit Southern Alliance for Clean Energy had started collecting used cooking oil from area restaurants. Green Energy Biofuel, a company based in South Carolina, bought SACE’s customers. A synergy developed that resulted in what is now known as Green Energy operating out of a UT-based facility.
Green Energy collects its liquid gold from all over South Carolina as well as East Tennessee. The Tennessee office services restaurants along the Interstate 75 corridor from Chattanooga to Bristol and Gatlinburg to Cookville. The company also picks up from all the collection centers operated by the city of Knoxville and Knox County.
That raw material gets a preliminary clean-up at Green Energy’s location at UT just off Alcoa Highway. Fried food particles are filtered out and the dewatering process begins. When 6,500 gallons have been processed, it’s off to Winnsboro, S.C. for processing into biodiesel. As well as becoming a component of commercial diesel fuel at the pump, some of the resulting product goes into a charcoal lighter fluid called Smarter Starter that is sold at Target, Lowe’s, Home Depot, and Whole Foods stores.
Green Energy is a partner in BIO4EDU, which provides funding to schools for educational programs promoting biodiesel production and use. It seems, though, that the idea is selling itself. The Environmental Protection Agency estimates that hotels and restaurants in the United States generate 3 billion gallons of waste cooking oil per year. When you consider how much it could cost to otherwise dispose of that stuff, it makes a lot more sense to turn it into a resource.
When Rudolph Diesel designed a peanut-powered engine, he couldn’t have been thinking about the global climate benefits of biofuels, where plants grown to produce the feed stock are removing carbon dioxide from the atmosphere. Fast food, processed food, and fried foods in general weren’t nearly as prevalent as now, so cooking oil wasn’t a huge waste stream for which disposal could be problematic. Diesel would have had no inkling of the environmental and geopolitical ramifications of our eventual addiction to crude oil and its distillates. Vegetable oil was simply easy to obtain and wouldn’t blow up in your face like some of the lower flash point fuels he had attempted to use in other inventions.
It seemed like a good idea at the time, and it seems a good idea now. If you want to do your part to make biodiesel a bigger part of our energy mix and reduce your environmental footprint, bring your used cooking oil in any non-glass container to any of the following locations during their respective business hours:
• City of Knoxville Household Hazardous Waste Facility, 1033 Elm St.
• Earth Fare, 140 North Forest Park Blvd.
• Southern Alliance for Clean Energy office, 3804 Middlebrook Pike
• Knox County Convenience Center, 3606 Neal Road
• Knox County Convenience Center, 10618 Dutchtown Road
• Knox County Convenience Center, 1810 John Sevier Highway
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