Right now, the U.S. biodiesel industry has roughly 1.5 billion gallons of production capacity on the drawing board-maybe more-and this speculative future volume is largely based on designs to construct large plants that consume virgin oilseed feedstocks and follow proven technological routes. Like it or not, that's simply how the maturing U.S. biodiesel industry is getting built out.

So why, in this growingly competitive business, would a small company rooted in a regional energy cooperative trouble itself with doing things differently? Why would the people behind Philadelphia Fry-o-Diesel LLC dedicate four years of their lives to proving that one particularly sordid variety of waste-restaurant trap grease-can be converted into ASTM spec biodiesel on a commercial scale?

Why? Because trap grease is widely available where they live. And they believe it can be done.

"We believe in using what you've got, and what we've got is restaurants, Fry-o-Diesel President Nadia Adawi says, explaining that trap grease is cheaper than yellow grease-the recycled vegetable oil that is discarded after making fried foods such as french fries. Yellow grease, unlike trap grease, is already being refined into biodiesel at various plants throughout the United States; it's also used as an animal feed ingredient. In other words, yellow grease has a market value. Trap grease doesn't.

However, despite the fact that trap grease is essentially free, there's a reason biodiesel producers aren't lining up for it. And perhaps that makes Fry-o-Diesel's story all the more compelling.

Adawi and her business associates, including Michael Haas, a research chemist with the USDA-ARS Eastern Regional Research Center, have roots in a Philadelphia-based energy co-op simply named The Energy Cooperative. The co-op's mission is to provide energy cost savings, as well as education and advocacy, on behalf of its members-particularly its low-income, elderly and disabled members-to promote the efficient use of both non-renewable and renewable energy.

Fry-o-Diesel's formation conjures up the cliché adage about challenges being opportunities in disguise. Indeed, it was The Energy Cooperative's own dilemma that led to the creation of Fry-o-Diesel in 2002. At the time, the co-op, which serves thousands of members in the Philadelphia area with renewable electricity and heating oil, was seeking an affordable, renewable alternative to heating oil. Biodiesel-or "bioheat"-was an attractive option, Adawi says, but it wasn't produced locally. Trucking in biodiesel (or biodiesel production feedstocks like soybean oil) from the Midwest was doable, but that process seemed to negate the environmental upshot of using the renewable fuel.

And there it was-that adage about finding opportunities within challenges was playing out after all-the idea for Fry-o-Diesel, a company that would produce its own fuel from a locally available waste product, was born.

Four years and an untold amount of intellectual and physical toil later, the company is now on the precipice of making its long-shot plan pay off. Adawi says construction of a 2 MMgy to 3 MMgy commercial-scale biodiesel plant is expected to commence by the end of the year. If that happens, the plant could start up in late 2007. Assuming the project develops as planned, Fry-o-Diesel would be the only source of locally produced biodiesel in the Philadelphia area.

Improving Trap Grease
Disposal Options
The irony of Fry-o-Diesel's beautiful plan is the repulsive nature of the raw material it's based on. Trap grease is a waste product in the truest sense. Haas calls it the "the foulest, ugliest" and most chemically challenging crude biodiesel feedstock he has ever brought into his lab. However, that didn't scare him off, and the scientist's decade of experience with low-value biodiesel feedstocks has brought a lot to the table for Fry-o-Diesel.

According to the National Renewable Energy Laboratory (NREL), a grease trap works by slowing down the flow of warm greasy water and allowing it to cool. As the water cools, the grease and oil separate and float to the top of the grease trap. The cooler water with less grease continues to flow down the pipe to the sewer. The grease is trapped by baffles, or deflectors, which cover the inlet and outlet of the tank, preventing grease from flowing out of the trap.

The grease, which turns solid at room temperature, must be collected in the trap, or else it congeals on the walls of sewer pipes and restricts flow, explains Debra McCarty, deputy commissioner of the Philadelphia Water Department. To prevent sewer blockage and backflow, food service providers are required by city laws to have their grease traps cleaned out at specific intervals. This service is usually performed by private businesses, such as septic tank service companies, for about 5 cents per pound, according to NREL. By creating value for what is currently a waste product, Fry-o-Diesel's plan could help both restaurateurs and the city, McCarty says, explaining that grease traps might be cleared more routinely if collecting and disposing of the unsavory material becomes easier and less costly.

Typically, collected trap grease is-or should be-brought to wastewater treatment facilities and processed for landfill disposal. Fry-o-Diesel will harvest the feedstock from traps at restaurants. The company is also negotiating contracts with existing trap grease haulers to have the waste delivered directly to its future biodiesel plant. "Trap grease haulers are thrilled to have a better disposal option for their grease," Adawi says, adding that restaurants and other producers of trap grease are universally excited to find a use for the waste.
To get a sense of the chemical makeup of the feedstock, Fry-o-Diesel spent a considerable amount of time sampling from traps, trucks and dumping sites. The company discovered that not only is trap grease unpleasant-it's extremely variable. "We've been trying to get a handle on what is typical, and we found there is no such thing as 'typical' trap grease," Adawi explains.

The combination is an assortment of fats, oils and greases (including animal fat, olive oil and vegetable grease), as well as food particles, dirt, water and anything else that falls down drains. The percentage of free fatty acids (FFA) in trap grease varies from 50 percent to 90 percent, although some samples collected by Fry-o-Diesel have come in below 10 percent, according to Process Technology Associates' Wes Berry, who has been working on the development of Fry-o-Diesel's process technology for over two years.

Clearly, the primary challenge for this company is tweaking existing process technology to handle this difficult and highly inconsistent feedstock. "By adapting the existing technology and know-how, the technology risks are minimized," Berry tells Biodiesel Magazine. Fry-o-Diesel uses the same basic steps as conventional biodiesel process technology, but the pretreatment of the feedstock is much more extensive; a methyl ester post-treatment is also involved. Berry says there is as much work involved in pretreating the feedstock as there is in the actual production of the finished product.

Another hurdle is odor control. Berry points to conventional techniques, but asserts that the system must be a lot tighter than a standard biodiesel plant. Before making the step to a commercial-scale plant, there are also some process challenges yet to be worked out-process modifications have been necessary to adapt to the very volatile, very high FFAs in the feedstock-and the company will likely use a mix of trap grease and recycled vegetable oil to regulate the FFAs and ensure oxidative stability. Berry says Fry-o-Diesel is still scrutinizing its post-treatment procedures in order to assure product quality.

Harvesting Opportunity
In part, Fry-o-Diesel's progress over the last two years has been facilitated by the $369,696 grant it received in 2004 from the Pennsylvania Department of Environmental Protection (DEP). The Energy Harvest Grant, awarded by the DEP's Office of Energy and Technology Deployment, is designed to promote and support the development of green business start-ups in Pennsylvania.

Fry-o-Diesel is precisely the kind of enterprise the program was created to support, and Dan Desmond, the agency's deputy secretary, says the DEP gets 10 times more applications for Harvest Grants than it can hand out. "It speaks well for those who get [them] because they tend to be at the top of their class," Desmond says, adding that the grant it presented to Fry-o-Diesel was on the high side of what is typically awarded through the Energy Harvest program.

Desmond says Fry-o-Diesel was an especially appealing project because it is an adaptor of novel technology in a rapidly growing industry. "Three years ago, Pennsylvania wasn't even on the national radar screen when it came to alternative fuel markets," he says. "This coming year, we may be among the largest biodiesel markets in the country." In fact, various reports show that demand for biodiesel in Pennsylvania could reach 40 MMgy by 2007, and Desmond says the timing for Fry-o-Diesel's emergence couldn't be better.
Adawi says Fry-o-Diesel has matched the grant with funds from The Energy Cooperative and in-kind donations from the USDA and Drexel University's College of Engineering, which has engaged engineering students in group design projects focused on such issues as trap grease pretreatment and computer modeling.

Haas and ARS biologist Karen Scott were instrumental in landing the USDA in-kind donation for the project. Two years ago, Haas requested that his office collaborate with Fry-o-Diesel as analytical and advisory partners. Since then, Haas' lab has worked closely with the company, analyzing the chemical composition and yield of the methyl esters produced at the pilot plant. "They've made great advances with the technology they're developing," Haas tells Biodiesel Magazine. "Pilot runs to date appear to have achieved production of [ASTM quality] product."

Adawi and her partners know fuel quality is critical, which is why the company will seek BQ-9000 certification, she says.

Going Commercial
Assuming Fry-o-Diesel is able to commercialize its process technology, one big question remains to be answered: Is there enough trap grease available to support a 2 MMgy to 3 MMgy plant in Philadelphia?

Because most trap grease is disposed of illegally, its actual availability is relatively unknown. However, NREL's estimates suggest that a city of 1 million people would produce enough trap grease to support a 1.7 MMgy biodiesel plant. At press time, Fry-o-Diesel was working with Philadelphia city officials to identify a site for its commercial-scale plant. Adaptations needed to take the process from pilot scale to commercial scale-improved process control automation, for example-are just now being identified. Final product testing will take place this summer and fall at the company's pilot plant. Pennsylvania State University's Energy Institute will compare emissions of biodiesel made with trap grease with that derived from more traditional feedstocks like soybean oil and yellow grease. A local school district has agreed to conduct test performance trials by using Fry-o-Diesel-made biodiesel blends in a number of school buses.

Once the commercial-scale plant is built, Fry-o-Diesel plans to maintain its pilot plant as a research facility for studying the use of other biodiesel feedstocks. In addition, the company's goal is to continue to hone the trap-grease-to-biodiesel model. "Our hope is to make this a model for other municipalities," Adawi says. "Grease in the water system is a problem everywhere-we've had inquiries from all over the world. We hope to … [help] other municipalities solve their trap grease problems."

Adawi believes Fry-o-Diesel's process technology is marketable, and the company is in the process of patenting it. Berry explains that the operating cost associated with the process is higher than a traditional feedstock plant and will also require a higher per-gallon capital cost. However, he says the reduced feedstock cost more than offsets the increased pretreatment and production costs on an annual basis. This means the overall cost for biodiesel from trap grease should be less than a conventional process.

"I think they have a good team and a good plan, and they're aggressive in business development," Berry says. "I'd like to see a bunch of these built. … Not only would that provide new sources of alternative fuel, but it would also reduce the troublesome grease load that wastewater treatment facilities now deal with."

Anduin Kirkbride McElroy is a Biodiesel Magazine staff writer. Reach her at amcelroy@bbibiofuels.com or (701) 746-8385.