Cooking Oil: Renewable Biofuel

Excerpts from Anne Vazquez,

Biofuel can lower the amount of greenhouse gas emissions their buildings are responsible for producing.Biofuels can serve as a replacement for the traditional oily used to run boilers for space heating or process steam production. An alternative to conventional fossil based fuels, biofuel is derived from biological material (often called biomass) and can be solid, liquid, or gaseous.

Many biofuels are favored because they burn cleaner than conventional fuels. This results in less pollution and lower greenhouse gas emissions. There are many materials that can be used to make biofuel. These include hemp seeds, soybeans, sugar cane, algae, agricultural waste (e.g. straw or wood), and used cooking oil. That last option—used cooking oil that has undergone treatment—is gaining increased attention and implementation in facilities.

Currently, this type of biofuel mainly replaces number 6 and number 2 fuel oil. Traditional number 6 and number 2 fuels are petroleum products; when they are burned, sulfur is released into the air along with particulates (e.g. ash content). Cooking oil fuel burns cleaner since no sulfur is released and ash content is in the range of .1% (versus about 2% with number 6 fuel).

One operational change is that the boiler can be set to a lower temperature to heat the fuel to a usable state. Conventional number 6 fuel requires continuous heating at about 220°F to 240°F for use, and our replacement fuel only requires heating to about 140°F.”

Meanwhile, the company’s number 2 fuel replacement does not require heating to remain liquid. However, Partanen explains it needs to be heated before being injected into the boiler. Facility managersinstall an inline heater to their systems in order to heat the fuel so it reaches proper atomization for igniting the boiler.

Biofuel isn’t currently price competitive for those using natural gas in their boilers. Natural gas prices are probably at an all-time low. However, that will swing considerably as the U.S. begins shipping shale gas overseas. But for those not using natural gas or who want to try biofuels for reasons other than cost, used cooking oil is a viable option.  (Today's Facility Manager, May 2012)