Patrick White 2013-04-03 14:47:35
A Behind-the-Scenes Look at Biodiesel Turning used cooking oil into an alternative energy source to power vehicles—and even heat school buildings. We live in an age of such environmental awareness, we’re taught that even trash is a resource! Today, our youngest children know that plastic bottles, glass jars and old cardboard boxes can be recycled and reused. Still, it can be a challenge to see any value in some of the waste we generate, such as used fryer oil. What possibly could be done with this often disgusting-looking byproduct? Well, after just a little processing, it can be transformed into biodiesel—a fuel used to power trucks and buses and even heat buildings. That’s pretty impressive for a material that for decades was left out by foodservice dumpsters by the barrel-load to be carted off to landfills. Biodiesel started to attract attention about 10 years ago, but largely as something of a novelty. A typical processor might have been an earnest college science major who collected used cooking oil from behind the local McDonald’s to convert it into biodiesel in his garage and power a rusty, old Mercedes Benz diesel station wagon. But times have changed. Thanks to steadily rising petroleum prices and new emissions regulations, the demand for domestically available, petroleum-free fuel sources now makes commercial sense, and there are for-profit companies specializing in the collection of waste cooking oil and the production of biodiesel. According to the National Biodiesel Board (NBB, www.nbb.org), some 112 million gallons of biodiesel were processed in the United States in 2005. By 2006, that number had doubled. And in 2011, more than 1 billion gallons were produced. While many K-12 school nutrition operations are eliminating fried foods from menus, some continue to offer these on a limited basis, especially at secondary schools not participating in the National School Lunch Program or as part of catering or concession services. If your program still uses cooking oil to prepare certain menu items, you might want to consider looking into biodiesel processing opportunities such as those found by the districts showcased in this article. Biodiesel Backgrounder So, what exactly is biodiesel? First, it’s important to note that biodiesel is not raw vegetable oil. While there are some individuals who have modified diesel engines to run on WVO (waste vegetable oil), these are rare exceptions, and WVO is not considered a legal motor fuel. In contrast, biodiesel is a regulated fuel source that must be processed to meet certain specifications. According to the NBB, “Biodiesel is produced from any fat or oil such as soybean oil, through a refinery process called transesterification.” The fuel that results from this chemical process can be used in nearly any diesel engine, usually with no further modifications required. It can be used alone (B100) or mixed with traditional diesel fuel. A blend that is 80% diesel and 20% biodiesel, for example, would be known as B20. Some biodiesel is made from “scratch,” using oil from soybeans and other sources; other biodiesel is made from “recycled” sources, such as used cooking or fryer oil. From an environmental standpoint, there are definite advantages to biodiesel. For starters, it produces 78% fewer CO2 emissions than petroleum diesel fuels. Biodiesel also is made from renewable resources. But there is one key factor working against greater use of the fuel: cost. Biodiesel generally costs more than petroleum diesel fuel, about 5 to 25 cents per gallon more, depending on the blend, according to the latest U.S. Department of Energy estimates. An Opportunity for Education One way to bring the cost of biofuel down is by having your own built-in source of vegetable oil. That’s the case for some school districts, which collect used oil from the school kitchen for educational purposes, i.e., teaching students the chemistry behind processing biodiesel. Others produce biodiesel on a larger scale to help power fleets of diesel school buses. At Birch Run (Mich.) High School, for example, students in the school’s 4-H program collect oil from the school kitchen, as well as from local restaurants, and have produced more than 1,400 gallons of biodiesel. This has saved the district money required to dispose of the oil, and the fuel has been used to help power district buses. Darlington County (S.C.) School District has 19 school kitchens supplying waste oil that the district processes for use in its fleet of activity buses that transport students to sporting and other extracurricular events. At State College (Pa.) Area High School, a biodiesel-based partnership between the school nutrition department, physical plant staff, the career and technical program and science teachers has helped save money while providing students a valuable educational experience. The project began about six years ago and “grew legs and just kept going beyond any of our thoughts,” reports science teacher Paul Heasley. Child Nutrition Director Megan Schaper, SNS, says her staff in the kitchen drains oil into containers and then e-mails Heasley when the containers are full and a pickup is needed. “We just save the containers the oil comes in, and when we clean the fryers, we just drain it right back into those and set it right outside the kitchen door,” she explains. From there, science students bring the containers to the district’s agricultural mechanics lab and empty them into a large tank. “After we have 40 to 50 gallons of used oil, the students pump 40 gallons of oil through a filter and into our biodiesel reactor. The oil is heated to 120°, and we add seven gallons of catalyst and mix for two to three hours,” Heasley explains. Once a chemical reaction takes place, the material is then “washed,” resulting in about 36 to 38 gallons of biodiesel. “After producing two batches of biodiesel, we write a physical plant work order to have them take the fuel to an elementary school to use as a supplemental fuel source,” adds Heasley. The physical plant then pays half the cost incurred in producing that fuel; the funds subsequently are used for improvements to the processing equipment or field trips to see other alternative energy production sites. The biodiesel produced represents only a small percentage of the elementary school’s overall heating fuel, but Heasley insists that the benefits go beyond student education—and they add up over time. “To date, we have produced about 2,240 gallons of biodiesel from the waste French fry oil. This has saved the foodservice department about $500 to $600 per year in waste hauling and the physical plant about $500 to $800 each year in fuel costs,” he details. Across the country, Rockwood Summit High School in Fenton, Mo., started its own biodiesel program roughly five years ago. Three of the district’s four high schools take a conventional route to kitchen oil disposal. “But at one school, they take the oil that we used to put in the dumpster and use it to produce biofuel,” explains Carmen Fischer, SNS, school nutrition director. There’s no extra work required on the part of the high school kitchen staff, notes Fischer; they simply fill barrels as opposed to putting the oil in dumpsters. The used oil is collected by student members of the school’s Biodiesel Club, and it is used as part of the chemistry curriculum to show how the process works. Plans are currently being considered to construct a standalone building at the school to house a Biodiesel Sustainable Fuel Research and Education Center. Why does the program take place at only one of the district’s high schools? “They have a teacher at that school who is interested in this and has, literally, fueled the fire,” says Fischer, with a laugh. Jokes aside, she estimates the cost savings to the school nutrition department at about $150 to $300 per year in used oil disposal costs. “It’s a good use for the oil and a win-win for everyone,” she summarizes. Back on the East Coast, Gaston County (N.C.) Schools has been operating its own biodiesel processing facility since 2005. Over that time, the school nutrition department has been supplying oil to the project, “but we’re not a major supplier, because we don’t use all that much oil,” notes School Nutrition Director Frank Fields. “The real source of most of the cooking oil that they’ve converted to biodiesel is from industrial sources and major restaurant chains.” At one point, the Gaston County district produced 100,000 gallons of biodiesel per year for district school buses. But that figure has come down recently, remarks Fields. While the school nutrition department continues to contribute its own limited used oil, supplies from many of the other, larger sources have begun to dry up. “It used to be a giveaway, but many of the larger suppliers now have their own programs where they’re either making their own biodiesel or they’re selling their used oil,” he explains. In other words, there’s a growing recognition of the value of the used oil, so it’s now harder to find for free. “The used oil is a commodity now, and people aren’t giving it away. That’s making it difficult to sustain this project,” says Fields. “It’s a changing dynamic.” Biodiesel production at Gaston County has become more sporadic, and with larger suppliers falling by the wayside, the school nutrition program now represents one of the larger contributors of oil. “We may be able to provide them 1,500 gallons every six months, and they’ll process that in only a day,” reports Fields. “It’s still helpful, but the project isn’t as large or as viable as it once seemed.” The Collection Connection For many school districts, it likely makes more sense to have any used cooking oil picked up by a specialized biodiesel producer than to try to make the fuel inhouse. General Biodiesel in Seattle is one example of a company that collects oil from foodservice kitchens and processes it into biodiesel. “We have a few thousand partners where we get oil from: restaurants, schools, prisons, airports, stadiums, anybody who is producing fried foods,” explains Zach Shelton, vice president of recycling operations at General Biodiesel. That oil is taken to a central facility where it is aggregated and used to create biodiesel. Shelton says that school districts are among the groups that General Biodiesel works with, but they represent a relatively small piece of the overall picture. “We’ve noticed a trend, at least locally, over the last several years where elementary districts—and some high schools, as well—are actually eliminating fried foods from the menus,” he observes. “That’s certainly not a general trend out there in society. There are still a lot of people eating fried foods. But within the school world, we have seen an impact [in the amount of oil available].” Different types of oil have different properties when they become fuel, says Shelton. For example, animal fat can gel up at high temperatures when used as fuel, similar to the way bacon grease will harden when collected in a can at home. “So, it is possible to make biodiesel out of animal fat, fish oil, palm and cottonseed oil. But we prefer— and, fortunately, it’s the norm—a clear liquid vegetable oil from fryers. That tends to make the best biodiesel,” explains Shelton. General Biodiesel typically does not pay for the oil it picks up, but it does provide collection services for free, so customers who had been paying to dispose of the oil see a modest cost savings. “One thing we provide our customers with is a sustainability credential,” Shelton adds. “That’s important to many of our partners, who use that credential in their own marketing efforts, and they think the whole idea of using the waste oil for fuel is cool, and they want to be part of it.” Looking to partner with a waste oil collection company? Be sure to check to see what the oil will be used for and where it will end up, advises Shelton. Large quantities of biodiesel end up being shipped overseas, he notes, which can counteract the environmental advantages the fuel can offer. Fuel that will stay local offers the greatest benefits, he asserts. As is the case with many waste oil collection companies, General Biodiesel supplies kitchens with special containers for the used oil. These containers range in size from 55 gallons to 350 gallons, depending on operation size. Then, regular pickups are scheduled based on the volume being produced. The goal, he explains, is to make the process simple for those running foodservice kitchens, hopefully spurring more people to send their used oil to be processed into biodiesel. “Most people don’t understand what happens to this resource. And why would they, really?” reflects Shelton. “If you’ve been operating a kitchen for years, you just know, ‘There’s a barrel out back that the oil goes into and somebody disposes of it, so I don’t have to.’ But it’s really great once they learn what that resource can be used [to produce].” Patrick White is a freelance writer in Middlesex, Vt., and a former assistant editor of this publication.
Published by School Nutrition Association. View All Articles.
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