Renewable Energy: The Power Of Reclaimed Cooking Oil
By Anne Cosgrove
Published in the May 2012 issue of Today’s Facility Manager
When seeking to lower the amount of greenhouse gas emissions their buildings are responsible for producing, facility managers (fms) might consider some form of biofuel as a replacement for the traditional oil they use to run their 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).
Whether the motivation is a government mandate to reduce pollutant emissions or the desire to stabilize the cost of heating fuel, fms may find that transitioning to cooking oil can be relatively simple. Though standard practice calls for phasing in the fuel gradually (by mixing it in with the traditional fuel) to ensure results are satisfactory, fms are not required to purchase new boilers or make major modifications to equipment.
Maintenance demands may increase, however, in order to keep boilers running smoothly. Addressing this point, Ray Albrecht, P.E., technical representative, northeast U.S. region, for the National Biodiesel Board, states that a workable scenario for boilers fired by number 6 fuel “would be to blend in a substantial percentage—20% or higher—of ASTM D6751 biodiesel, which due to its known solvency effect can do a good job of keeping burner components clean.”
If their organization uses cooking oil as part of its core operations, fms have the option to install a system on-site to treat and reuse their own cooking oil. If not, fms can purchase used and treated oil from a vendor who will deliver it to their sites.
Bill Partanen, director of business development at AmeriStar, a Bethlehem, PA-based producer of biofuel made from used cooking oil, says, “The fuel we make to replace number 6 fuel is basically a drop-in fuel; the facility is not required to make any major equipment changes. 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. Fms install an inline heater to their systems in order to heat the fuel so it reaches proper atomization for igniting the boiler.
Says Partanen, “Our market for this biofuel has primarily been the utility and manufacturing sector—facilities that require process heat. However, we have begun working with other building types more such as colleges and universities, office buildings, and high rise residences. We look at the type of boiler equipment they have, what type of storage they have available for the fuel, and other factors that will determine if the fuel will meet their needs.”
Partanen notes this 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,” he says. 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.
As this market continues to take shape, fms who operate food service facilities should be aware that cooking oil used in their organizations can be a potential source of revenue. The price paid varies, but on average, biofuel producers will pay between 50¢ to $1.00 per gallon for the oil. Fms can eliminate fees they pay for oil disposal while creating a revenue stream.
Biofuels have been in use to one degree or another for many years. And fms must evaluate the various sources and how it will impact their equipment and budget. Used cooking oil may be an alternative for fueling heating and process steam needs.