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HomeMy WebLinkAboutAppendix M- Biodiesel article Sept 2008 Search Articles Advanced Search Current Issue Subscribe Current Issue Subscribe Now Search Archive Digital Editions Ethanol Producer Biomass Magazine F.A.M.E. Forum Biodiesel Radio View current issue here View past issues here Improving the Bottom Line On the Front End To avoid high-priced virgin vegetable oils, many in the industry are looking for alternatives. But inexpensive feedstocks are cheap for a reason—they carry high levels of undesirable components such as free fatty acids that make it difficult to produce biodiesel. Pretreatment systems, however, can clean up less than desirable feedstocks and improve producers’ bottom lines. By Jerry W. Kram It may be hard to believe now, but only five years ago there was a glut of virgin oils such as soybean and canola oil on the market. Indeed, that was one of the driving forces behind the development of the biodiesel industry, as soybean growers looked for new uses and markets for their crops. The surge in worldwide demand for oils along with the growth of biodiesel use have pushed the price of virgin oil up from 20 cents per pound to a point where it is consistently more than 60 cents per pound and occasionally pushes the 80- cent barrier. The price pressure for virgin oils sparked an intense search for alternatives. While algae and jatropha hold promise for the future, biodiesel producers are looking for alternatives that can help them now. Many are trying to adapt to feedstocks that were formerly thought of as less desirable, such as animal fats and waste vegetable oil, also known in the industry as yellow grease. These feedstocks are certainly less expensive than soybean oil and can be made into high-quality biodiesel. However, they typically contain high levels of substances that can make a biodiesel producer’s life miserable. Chief among these are free fatty acids. Fatty acids are the main component of both fats and biodiesel. In virgin soy oil, three fatty acid molecules form an ester with glycerin. Transesterification breaks the fat molecule with sodium methoxide catalyst and creates three molecules of biodiesel. However, if the fat molecule has been broken, which happens when oils are used for frying, for example, and the fatty acid molecule is free in solution, the catalyst combines with the fatty acid to form soap. More soap formed in the biodiesel tanks means more washing and purification for the biodiesel producer. “During the transesterification process, the chemical reaction that occurs actually can’t convert free fatty acids (FFAs),” says Doug Lindsey, a biodiesel application specialist with SRS Engineering Corp. of Murrieta, Calif. “Besides creating soaps, it impedes the reaction.” Article Continues After Advertisement Object ١ Object ٢ Home | Current Issue | Subscribe Now | View Archives | Events | Plant List | Ethanol Producer Magazine | Biomass Magazine | Advertising | About Us | Contact Us 308 2nd Avenue North, Suite 304 Grand Forks, ND 58203 (701)746-8385 Fax:(701)746-5367 Subscription Fax:(701)738-4927 © 2008 BBI International Media Search