Trap waste, or FOG, is a highly variable waste product. When removed from restaurant grease traps, it is composed of wastewater, grease, oil, food particles, restaurant waste (i.e. napkins, plastic forks) and other non-digestible debris. Typically less than 5% by weight of each gallon of trap waste is a digestible or refinable lipid. Systems which focus on refining the grease component of trap waste are leaving the other 95% of the waste disposal challenge to someone else, often having an economic, environmental and energy cost.
Common heat processing of separated or rendered FOG grease has demonstrated the benefits of this source material, but comes at a high cost – the energy or chemicals required to pre-process, heat treat, render or mechanically separate produces waste by products, often involves chemical treatments and pushes the non-lipid FOG waste components into someone else’s waste stream, degrading the environmental benefits of processing FOG. These additional costs are rarely included in the analysis of the productivity or feasibility of other FOG handling approaches. If the FOG handling and processing challenge is properly addressed, however, FOG Waste is an energy dense material, which can also be used to meet today’s sustainability and green goals. In fact the FOG Energy System extracts over 90,000 BTUs of energy from every gallon of grease processed – making it as rich a source fuel as typical fuels like Ethanol and Diesel.