Trap grease is food wastes separated from the waste water that goes down the drain in a restaurant.  It’s caught in a "grease trap." It’s a useless waste product that restaurants and haulers pay to have collected and incinerated or dumped in landfills. 

Restaurants pay trap grease haulers to pump out these traps and the haulers then pay to dispose of the trap grease. Until now!  PFoD’s patent pending technology makes it profitable, without subsidies, to use trap grease as a raw material for fuel. 

Converting trap grease into a pure fuel is a daunting chemical and engineering challenge because it requires separating and treating everything that goes down the drain in a restaurant.  In the words of one of our collaborators at the US Department of Agriculture “Trap grease is the foulest, ugliest, chemically most-challenging crud I have ever brought into my lab.”

But besides being foul crud, it’s also an abundant feedstock for fuel. The National Renewable Energy labs estimates that 495 million gallons of trap grease are generated each year nationwide, concentrated in major population centers where, incidentally, most diesel fuel is used.

Most municipalities around the world require that all restaurants and food service facilities  install a grease trap to “trap” the wastewater before it can go down the sewer lines. A grease trap works by slowing down the flow of warm and hot greasy water and allowing it to cool. As the water cools, the fats, oils and greases separate and float to the top of the grease trap allowing cleaner water to flow down the sewer lines. Traps are required to be pumped at specific intervals by law, typically every three months, depending on size.

But, noncompliance is rampant and regulators have been reluctant to crack down on poorly maintained traps and trap grease collectors because disposal options are limited and expensive. Few wastewater treatment plants accept trap grease and haulers are forced to drive long distances and pay high tipping fees for grease disposal. The few plants that do accept grease were not designed to accommodate the large volumes of grease they receive and are plagued by equipment downtime.

If a trap is not properly serviced, the grease simply passes through the trap and enters the sewer system. Data collected by the EPA suggests that grease is the primary cause of 40% - 50% of sewer overflows nationwide and a secondary factor in another 10% - 25% percent. When combined sewers overflow, grease and other untreated contaminants enter the watershed, polluting local bodies of water including creeks, streams and rivers.

Currently, there is no good use for trap grease; it is simply a waste product, most typically disposed of at sewage treatment facilities.

By working with food service facilities and grease haulers, PFoD provides an environmentally preferable solution for the disposal of trap grease. By developing innovative technology to convert trap grease into biofuels, PFoD can minimize the amount of grease escaping into the water supply and lessen the processing demands for the already overtaxed wastewater treatment facilities. Most importantly, PFoD produces a renewable energy fuel from an otherwise useless waste product.

Current domestic biodiesel production uses virgin vegetable oil, a high cost feedstock. 

To a lesser extent, biodiesel is also made from fryer grease, the oil in restaurant deep fryers that must be changed periodically. Fryer grease is an excellent source of biodiesel feedstock, however, there is already a robust market for this waste grease. Currently, most fryer grease is cleaned and sold as an additive for animal feed. To utilize fryer grease for biodiesel production, it would need to be purchased at the high market rate that the animal feed market commands.

Trap grease can be a cost effective feedstock for biodiesel. The high cost of biodiesel is the single biggest barrier to widespread use. Biodiesel plants across the country are closing down because of the high cost of soybean oil.

Philadelphia Fry-o-Diesel demonstrates that ASTM-standard biodiesel can be produced from trap grease at a cost that is competitive with petro-diesel products.