Photographs by Whitney Curtis
In 1989, Thomas Reed pulled up to a McDonald’s in Colorado and asked for a gallon of waste oil from their fryers. Workers directed him to the grease dumpster out back. A chemistry professor at the Colorado School of Mines, Reed experimented with the grease back home.
Techniques to make diesel from virgin oil had long been in place, but using waste oil wasn’t as well understood, and Reed realized grease was remarkably abundant and inexpensive. After letting the water and fried bits of food settle, he mixed it with lye and added methanol.
The result was potent enough to power diesel engines.
Reed decided to sell the product. He made a batch of 100 gallons and took it to Denver’s RTD bus service for testing. He even named it McDiesel and applied for a copyright, but McDonald’s threatened to sue. When mixed with normal diesel, the fuel burned efficiently and produced few pollutants. Reed never got rich from the concoction, but biodiesel home-brewers across the country eventually adopted his practical recipe.
More than 20 years later, I pull into the Lemp Brewery at 5 a.m. to ride along with Kelley Green Biofuel, a local company that’s among the first in the area to use waste vegetable oil on a commercial scale. I drive in through a narrow alley, with warehouses looming on either side. The Lemp Brewery, a 14-acre complex of aging brick industrial buildings on the South Side, has been closed since Prohibition. Underneath it are natural limestone caves that were used by German beer tycoon Adam Lemp to cool lager in the 1840s. Following instructions over the phone, I turn, and my headlights land on a waving figure perched on the back of a truck.
Joel Carrico picks up grease for Kelley Green Biofuel. Orange earplugs, like an airline baggage handler’s, dangle around his neck, but he doesn’t use them today, despite operating loud machinery. “I don’t have any others,” he says, “but I won’t make you suffer alone.” Inside the warehouse, 50 white plastic storage totes of grease are arranged in rows across the floor. He climbs into an Isuzu with a pill-shaped tank in the bed and pulls onto Lemp Avenue.
We head toward Washington University, one of Kelley Green’s biggest clients and company founder Kristopher Kelley’s alma mater. Kelley developed the business plan while in college and invited Carrico to join after Kelley graduated in 2008. Today, Kelley oversees production in Kentucky, while Carrico handles grease collection in St. Louis.
We pull up to a loading dock outside of a Wash. U. food court. Carrico jumps aboard the truck bed and uncoils a long hose to two green metal drums. The vegetable oil’s surface reflects black in the dark morning, like a barrel of sweet crude. The metal grate on top is jammed with crusted bits of food; the smell conjures chicken wings and mozzarella sticks. Carrico sticks the tube into the liquid below, and the fluid begins to drop quickly. He tilts the drum and sticks the tube into the corners, sucking up the grease residue. I recall Daniel Plainview’s famous line from There Will Be Blood: “I drink your milkshake.” At another dining hall, a bemused food-service worker chuckles: “You take vegetable oil, and you get fuel... Man, that’s something.” At the last stop on campus, fries, tater tots, and onion rings sit on the oil drum’s grate. Carrico pushes them through the lattice to be sucked up with the grease.
At a hospital, he warns about the risk of tipping over a drum; they’re housed deep within the facility, and must be wheeled over cracked floors and through a bustling kitchen. “I’ve never had a big spill,” he says, “but the potential is there, and it is terrifying.” He shows me the sack of absorbent pebbles carried in the truck just in case, “the same as when some kid vomits in the middle of school.” The food waste in the drums is denser than oil, so as the oil is sucked up the hose, the food appears at the bottom, a light-brown mash that looks like gravy.
After a few more stops, Carrico calculates we’ve almost filled the tank, so we return to the Lemp Brewery. He sticks the hose into a storage tote, and the morning’s grease shoots out the end, golden in color. In a little more than three hours, we’ve collected about 450 gallons of waste vegetable oil.
“Next, we let gravity do its work,” says Carrico. “After a few days, the bottom third will be food, then about 10 to 12 gallons of oily water, and the rest is a nice, dark, rich color.” The food and sediment will go to waste disposal. The oil will be driven to Goshen, Ky., home of Kelley Green’s processor.
Despite its potential, little biodiesel made from waste vegetable oil is churned out in the United States relative to other energy sources.
After Reed discovered the simplified recipe, he met resistance from policymakers and energy scientists. Instead, researchers made biodiesel from a variety of virgin plant oils, from olive to coconut. In Europe, biodiesel plants began to turn soy and canola crops into diesel, but deep-fryer grease could not meet the exact tolerances of commercial fuel production.
Others, however, welcomed the idea. Filmmaker Nicole Cousino drove across the U.S. in a diesel van, collecting grease and cooking it into biodiesel on the spot; the result was the 1995 film Fat of the Land. Biodiesel enthusiasts began to pop up around the country, hauling oil from restaurants and feeding it through improvised processors.
Today, biodiesel brewers remain an amateur bunch—an underground network of alchemists concocting diesel in their kitchens and advertising it on their bumpers. The field is decentralized, with low investment barriers; an initial setup can cost less than $100. It is fairly low-tech—handyman’s technologies, compared to corporate R&D. (Home setups can look a lot like high-school science projects, with blenders, electric drills, and spaghetti strainers.) As a result, there’s a community surrounding grease, a counterculture salvaged from fryers and cooked up at home.
In these circles, grease is called “WVO”—waste vegetable oil. Internet sites make expertise, equipment, and oil easily available. Websites document in exquisite detail how to make biodiesel, with article titles like “Methoxide the easy way.” Early WVO users had to get methanol sold as paint thinner or stove fuel; now they can buy a 55-gallon drum for $165 online.
Home-brewers use a variety of waste feedstocks: chicken grease, soybean oil, canola oil, peanut oil—typically, whatever’s in the fryer at the end of the week. Many go to fast-food joints or Chinese restaurants. The market for WVO can be competitive—it is, essentially, free fuel—and grease haulers sometimes steal behind each other’s backs. (Carrico and Kelley didn’t know why Wash. U.’s pressurized tank was rarely full until a university employee tipped them off that another local company was taking the grease, despite Kelley Green’s contract. The next morning, Carrico put a lock on the pipe.)
Granted, WVO-made biodiesel has its limitations. Biodiesel is viscous (it “gels” in winter conditions), so it must be mixed with petroleum diesel. This is why many aficionados elect to burn straight vegetable oil, or SVO. Rather than converting it to diesel, they convert their cars (1980s-era Mercedes-Benz diesel sedans are most popular). In the United States, using SVO as fuel isn’t even recognized as legal, but a wide variety of conversion kits are sold. Many kits use two fuel tanks; the engine is ignited with diesel fuel, then switched over to SVO once it’s warmed-up enough to flow.
Tower Grove Park resident Suzanne Renard converted her 1984 Mercedes-Benz. Instead of a double tank, she says, “The single tank contained a heater to warm up the oil, thinning it so that it would flow through the engine without gelling up—unheated oil could turn to a lardlike consistency and wreck everything.” She collected high-quality grease from a Middle Eastern restaurant, let the solids settle, and triple-filtered the oil before pouring it in her gas tank. People told her the exhaust smelled like falafel. Her beloved Mercedes recently met its demise after an accident.
“The police and fire fighters were fascinated by the car, wanting a tour of the systems, from trunk to engine,” she recalls. “It turned into a mini how-to seminar, on the last day of my own practice.”
A week after my outing with Carrico, I visit Kelley Green Biofuel’s diesel processor, located at Woodland Farm, 20 miles outside of Louisville, Ky. The farm, owned by Kelley’s uncle Steve Wilson and aunt Laura Lee Brown, encompasses more than a thousand acres of dense forest and bison grazing on rolling hills.
Kelley greets me at the car. He’s tall and lanky, with a mess of dark-brown hair, a thick beard, and glasses. We walk down a short hill, to where he’s walled off a tall room at the end of a farm shed. Packed inside is his processing machinery: two 12-foot-tall green tanks wrapped with silver insulation; a pair of narrow dry-wash towers; a squat steel mixing tank; a shiny rectangular collection tank for finished biodiesel; an intricate design of tubes, valves, motors, and pumps. (Picture the array of tanks and snaking pipes at an oil refinery, and shrink them to one-tenth scale.)
He’s started a batch of biodiesel just before I arrive. The first step: continuously heating and cycling the grease through spinning centrifuges to remove impurities. As the centrifuges work, we visit his apartment in a neighboring farm building, so he can titrate an oil sample.
Kelley is easygoing, with an agreeable Southern drawl, and he whistles as he mixes chemicals and makes calculations. He grew up on a farm in Bardwell, Ky., a couple hundred miles to the west, where his family grew much of their own food. Like his father, he tinkered with motors and machinery, and inherited a desire to own his own business. In high school, he and Carrico started a T-shirt design company. During college, Kelley sought a varied liberal-arts education—creating his own major, aesthetics and society—while studying entrepreneurship. "I took an entrepreneurship class, and we had to come up with a business idea,” he recalls. He began looking into biodiesel, and continued with an independent study the next year. Early on, he realized using recycled feedstock was the only economically viable option. “The more research I did,” he says, “the more potential I seemed to find.”
After graduating, he launched Kelley Green Biofuel, collecting and storing grease in the Lemp warehouse in fall 2008. “I wanted to do a much larger-scale operation, but I came to realize that you have to have a lot of oil—like a million-gallon minimum—and there’s no way that I could have that much ready on a given date,” he says. “So I decided that I had to build a smaller operation and increase the amount of oil that I collected.”
Kelley met hurdles, however, when he set out to get the necessary municipal permits. “People hear biodiesel, and they don’t understand. They just hear the ‘diesel’ and think everything is going to burn down.” (Since biodiesel has a high flash point, it actually has a relatively low risk of explosion.)
“My uncle came and visited, saw what was going on, and said, ‘Why don’t you build your first processor on the farm?’” he recalls. His uncle’s operation, Kentucky Bison Company, already used “a tremendous amount of diesel.” He bought the truck, got the plastic storage totes for the warehouse, and started salvaging metal drums. He also began pursuing grease contracts. “I actually talked to Wash. U. when I was still in school about collecting their oil,” he says. “They said, ‘Oh, but we couldn’t have a student making money off the school.’” So he signed a contract to collect Barnes-Jewish Hospital’s grease, then contracted with other food-service operators in the medical complex. Last year, Washington University Dining Services signed on.
At the time, Kelley’s processing capacity wasn’t sufficient to deal with such a load. “When I started looking into processors, I thought I was just going to buy one,” he says. “But I realized, to get it the way I want it, I really needed to build my own.” In designing the operation, Kelley put a premium on materials that would otherwise go to waste. Soon, he was spending more and more time working on the farm’s processor, leaving Carrico to handle the collection. They eventually made the arrangement permanent.
The processor is still in a state of continuous change. “The first time, I started with unsettled oil, and it centrifuged for 24 hours before it was clean,” says Kelley. One problem led to another. The first Venturi vacuum was too small, the larger vacuum made the system overheat, and the water jackets had to be completely replaced. Recently, he had to swap all of the system’s brass fittings for stainless steel, after discovering a green residue where the brass had slowly reacted with the diesel.
Today’s batch is the first to be made with the upgraded system.
Kelley sets lab equipment on the kitchen counter of his apartment: beakers, a mixer, a graduated cylinder, and sterile syringes. He washes everything meticulously, to avoid contaminating the sample—if one measurement is off, the whole batch could go wrong. Kelley shows me a canister of pure yellow oil, high-quality grease from his aunt and uncle’s Louisville restaurant, Proof on Main. Fast-food operations change their oil far less frequently, so it contains more particulates and free fatty acids.
In a beaker, Kelley mixes 1 milliliter of an oil sample with 10 milliliters of rubbing alcohol and a pinch of turmeric. He drops in a metal paddle and sets it on the mixer. Powered by a rotating magnet underneath, the paddle begins to twirl rapidly, churning the liquid into a yellow broth. With a syringe, he titrates, adding drops of a known base, counting each one as it briefly flashes magenta. In his other hand is a timer; the solution must stay magenta for 30 seconds. The amount of base needed to turn the turmeric this color will indicate the pH. The next drops stay magenta just a second longer, and suddenly the entire beaker bursts bright purple. Two milliliters.
Grinning, he declares, “This oil is really good.”
After returning to the processor, Kelley unscrews the small centrifuges and scrapes out the congealed black goo. He turns on a pump, and resin-colored oil begins to fill the tank where the diesel reaction will occur. A transparent hose next to the tank has black lines drawn on to measure the volume, like the glass tube on a coffee machine. After several minutes, the oil levels off at 705 liters.
He’s ready to blend lye and methanol to make the catalyst. The mixer—industrial salvage, originally used to stir paint—has a paddle that spins at the bottom. Kelley starts up a vacuum to draw the clear methanol into the mixer; to add lye, he ascends two ladders to a pine platform. There, he puts on a gas mask, makes a calculation on his iPhone, and shakes the white powder from a paper sack, then pulls out chunks with gloved hands, until the scale’s screen reads 5,217 grams. The lye tumbles down a chute into the mixer, to be blended with the methanol for an hour while we go grab lunch.
At Big R’s Bar-B-Q in nearby La Grange, over pulled pork and brisket sandwiches, Kelley discusses the state of his company. He currently has about five large accounts—hospitals, Wash. U., and a few other St. Louis–based companies—that total around 3,000 gallons of WVO a month. Collecting grease contracts has been much simpler than turning it into diesel, so Kelley isn’t pursuing more supply right now.
Determining the value of waste oil is complicated. In areas of the country where there is an established market, collectors might pay more than $1 per gallon, but elsewhere businesses still treat it as refuse and pay to have it hauled away. Kelley Green picks up grease for free. For many institutions, the positive public image alone makes it worthwhile. “Businesses promote that their oil is going to renewable energy,” Kelley says. That promotion also benefits his company: A recent newspaper article about the Wash. U. contract led to an agreement to collect grease from Energizer.
The scale of Kelley Green’s biodiesel production is still limited—fuel is sold to local farms and Washington University Dining Services. But Kelley can make biodiesel for around $1 a gallon. Blended at 5 percent with normal diesel, it runs in any diesel vehicle. “If you look at my per-gallon cost, it would be way less than any other fuel, less than it costs just to refine gas,” he says. This is important: “From a philosophical standpoint, I think that sustainable alternatives should not and do not have to cost more.”
Kelley is currently forced to truck his product back and forth to the farm (using a truck that runs on biodiesel mixed with the conventional variety), but in the next few years, he plans to build a processor in St. Louis and develop his company in several different cities. “All bigger operations than I have now, but none of them that large,” he says. “So I can collect locally, produce locally, and sell locally.”
Worldwide, the field of companies making diesel from WVO is small, but growing. In the U.K., McDonald’s has begun running its fleet of delivery trucks on fuel made from its own fryers. Because so many producers are small, the sector flies largely under the radar. No cumulative data are available. But while WVO biodiesel certainly can’t serve as our sole source of transport fuel, it’s estimated that the oil poured from fryers in the United States totals nearly 3 billion gallons annually—which, if fully used, could replace more than 1 percent of our petroleum consumption.
The vast majority of biofuels available commercially, though, are made from virgin oil, rather than waste. Soy-based biodiesel is the most common type in the U.S., and is widely used in Europe. Corn ethanol is now blended into some 70 percent of gas nationwide, and production has been increasing rapidly; in 2009, a full quarter of the American corn crop became fuel. Proponents say corn ethanol provides American jobs and national security. At the same time, critics disparage making fuel from corn for a number of reasons: They say it disrupts world grain markets, depends on fossil fuel–intensive fertilizers, and provides little help in slowing climate change.
Still, ever more promising commercial-scale biofuels are coming down the pipeline. “I think fuels made from algae, in particular, are going to be important in the future,” says Kelley. Cultivated in open ponds and transparent tubes, algae can be used to produce either ethanol or diesel, and may be able to generate 30 times more fuel per unit of land than soybeans, with far fewer fossil-fuel inputs. Algae fuel, though, is still in the future; science hints at possibilities, but the technology isn’t yet commercially viable.
Waste vegetable oil, on the other hand, is everywhere for the taking—to cook it into biodiesel takes only an adventurous soul.
After lunch, we return to the farm to find the smoke detector going off.
Apparently, the heat of the reaction alone can set it off. The catalyst is now blended milky white, ready to be added to the oil. Kelley opens valves and turns on a motor to draw it into the tank—but through a tiny glass window, he sees that the level isn’t going down. There must be a clog. Trying to locate the source of the problem, he tries flushing the valve with an air compressor. Suddenly, methanol fumes escape into the shed. He scrambles to shut the right valve, and I rush outside for fresh air. I’m startled to see dozens of bison grazing on alfalfa and clover nearby.
Earlier in the day, Kelley mentioned that, as a side project, he was interested in finding a market for the buffalo hides, a byproduct of Kentucky Bison Company’s meat-processing operations. He seems to view everything through the lens of salvage. The plastic storage totes, the processor tanks, the grease collection barrels—all were industrial waste. The pickup truck came from a lawn-care company. Glycerin, a chemical byproduct, currently goes unused, but Kelley hopes to burn it soon as fuel for heating the processor tanks.
There are definite benefits to this sort of reclamation. “I go to industrial-salvage lots and see things that work perfectly for my use,” says Kelley. His approach takes more time and effort than buying new, but he saves money, as well as “the massive amount of energy it takes to make a huge tank out of metal,” he says. You might expect established companies to see the value in both the machinery and the waste oil, but Kelley says that’s mostly not the case. Even if they did recognize it, he points out, among the industrial-salvage outfits in Louisville, “none of their stuff is on eBay; none of them have a searchable inventory.” Consequently, he spends hours prowling junkyards for valuable equipment.
Back inside the shed, he continues blasting compressed air into the clogged area, which eventually clears. The catalyst level begins dropping, and the diesel reaction—transesterification—instantly begins.
For Kelley, the core of his business lies in the salvage of waste. “The very nature of the oil is a byproduct,” he says. Conventional uses for WVO—integrating it into animal feed or soap—involve shipping the material over great distances, burning more petroleum in the process. Often, the oil is simply treated as sewage, the energy inside completely squandered. “I think it’s our responsibility to know where our waste stream is going, so that’s what I provide,” says Kelley.
Most policymakers don’t view WVO biodiesel as a legitimate fuel source: It’s dirty, unconventional, and comes in small batches. What they don’t realize is that collectors of grease are providing a valuable service, literally sucking up the fat leaking out of the system. Kelley knows his product will never replace petroleum on its own, but he’s confident in his business model, because the oil is a byproduct that people are happy to have him haul away. “If there’s a big breakthrough in renewable fuels,” he says, “then I think biodiesel from waste oil could still fit in, because it’s so cost-effective.”
After 90 minutes, the reaction has converted the fatty acids into a tank full of biodiesel. Kelley draws a beaker of fluid from tank No. 2. It’s cloudy at first, frosted yellow. After a few minutes, it settles into two discrete layers: Glycerin pools at the bottom, below a strikingly clear fluid, pure gold—diesel.
Kelley says he’ll further purify the fuel, then blend it with petroleum diesel to be sent to customers in St. Louis and Kentucky. Back at Wash. U., it will help fuel the diesel trucks that ferry food around campus—including, among other things, mozzarella sticks and onion rings. 7
Joseph Stromberg is a recent graduate of Washington University. He became interested in biodiesel while compiling an anthology on the topic of waste. Stromberg is currently spending a year in India on a William Jefferson Clinton Fellowship.
