Used Cooking Oil Recycling
Used cooking oil (included in the waste stream category of Fats, Oil and Grease (FOG)) presents interesting disposal issues. The New York City Department of Sanitation requires that liquid cooking oil be disposed of by absorbing into paper towels, cat litter, or some other absorbent material, or by placing in a leak-proof container, or by freezing it solid.
Drain disposal of fats, oil and grease is illegal in NYC, as well as in most parts of the United States. FOG (including liquid FOG) disposed of via the drain build up on the inside of waste lines, congeal and trap other solid items, growing to terrifying size, ultimately clogging waste pipes and sewers. FOG disposed of via the drain in residential buildings may not even make it as far as the sewer, and clog drains and waste lines on the property, resulting in sewage backup into sinks, toilets, bathtubs, showers, floor drains.
Waste cooking oil can now be considered a commodity. Commercial generators of waste cooking oil often collect this waste stream for recycling. Recycling is always preferable to disposal because it conserves resources, diverts significant volume from landfills - and may generate revenue. Waste cooking oil (and other FOG components) is used to make fertilizer, soap, cosmetics, and other products; most of the waste cooking oil from Lehman College is recycled into Biodiesel.
Approximately 5 tons of FOG (predominately liquid waste cooking oil) was collected from cafeteria operations at Lehman College in 2013. Waste cooking oil is accumulated in a secure collection container, and removed from campus several times per year by a licensed recycler. The waste cooking oil is processed into biodiesel.
Biodiesel is a biodegradable, nonhazardous, combustible fuel made from vegetable oils and/or animal fats. Biodiesel can be used (with or without blending with regular petroleum diesel) in any type of engine that accepts diesel fuel; engine modification is unnecessary. Raw materials for biodiesel come from renewable, domestic sources. Biodiesel burns more cleanly than petroleum-based fuels.
Biodiesel can be made from fresh oils and fats, or waste oils and fats. Either starting material requires processing in order to be used as fuel. Unprocessed oils and fats (high viscosity, burns poorly) will NOT work as fuel in a diesel engine! Detailed descriptions of converting oils and fats into biodiesel can be found hereand here (video).