The recycling of used cooking oils into biodiesel fuel has been a trend in onsite foodservice for a number of years, but a few programs are now taking that process a step further. They are using glycerin, a byproduct of biodiesel production from cooking oils, to make soap, as well as related products like shampoo, laundry detergent and surface cleaners.
Either way, the process illustrates how green technologies can sometimes expand into unexpected areas to close waste cycles and provide value-added benefits beyond what was originally conceived.
The process by which soap is produced from glycerin is fairly simple. Used cooking oil is converted to biodiesel by being exposed to methanol, a type of alcohol. The reaction produces glycerin as a byproduct.
The glycerin is then mixed with potassium hydroxide to produce soap as well as other products ranging from fertilizer to anti-freeze, says Zach Waickman, biodiesel lab manager at the Center for Urban Environmental Research at Loyola University in Chicago. “The high glycerin content makes it very effective for cutting grease and acting as a moisturizer,” he says.
At Loyola, the now-four-year-old program, which started as a class project (a student came up with the soap formulation) produces up to 10 gallons at a time, which is then packaged and sold in various formulations as Biosoap at the campus bookstore and at local farmers markets.
The glycerin comes from the conversion of used fry oil from Loyola's dining outlets (and some nearby restaurants) into biodiesel, which powers shuttles connecting the school's two campuses. Waickman says this is only the beginning, since the project is nowhere near using all the glycerin available. “Frankly, if we used it all, I could have a soap factory,” he says.
At Brigham Young University of Hawaii, Professor Daniel Scott developed a program two years ago to turn glycerin byproduct from biofuel production into laundry and hand soaps for the campus dining services.
Scott had been approached by Dining Services Director David Keala, who was looking for a way to use the glycerin produced by an outside biodiesel processor, Hawaii Reserve, Inc., which was taking the department's used oil and converting it to biodiesel.
Scott's lab produces enough liquid hand soap to meet all of the foodservice operation's needs, about 30 liters a month. It is now also being introduced in residential housing operations and has been sold by the 7.5-oz. bottle for the past few months at BYU-Hawaii's farmers markets. A potential exterior market has also emerged as the Polynesian Cultural Center, a major tourist site, has requested samples to try in their food operations.
In addition, a laundry soap version is currently being tested in the foodservice and athletics departments, and a formulation that includes sanitizers will be tested this fall as a surface and floor cleaner.
In all, Keala estimates that BYU-Hawaii can save some $15,000 a year by switching to the in-house product. “We feel confident that as we expand our soap usage towards our other cleaning chemicals,, that those numbers will dramatically increase,” he adds.
(For a video of the BYU soap making operation, go to the “FM Editorial” channel at www.video.food-management.com.)