Spanish company touts process to turn urban waste into biodiesel
Using microbes to convert organic material into energy isn't a new concept to the renewable energy industries, and the same can be said for the anaerobic digestion of organic waste by microbes, which turns waste into biogas consisting mostly of methane. However, using bacteria to convert urban waste to fatty acids, which can then be used as a feedstock for biodiesel production, is a new twist. The Spanish company calls this process and the resulting fuel Ecofa. "It is based on metabolism's natural principle by means of which all living organisms, including bacteria, produce fatty acids," Angula said. "[It] comes from the carbon of any organic waste."
He defined urban waste as "organic wastes from home like food, paper, wood and dung," and added that any carbon-based material can be used for biodiesel production under the Ecofa process. "For many years, I wondered why there are pools of oil in some mountains," he said, explaining the reasoning behind his invention. "After delving into the issue, I realized that [those oil deposits] were produced by decomposing organic living microorganisms." This, in Angulo's mind, sparked the idea that food waste and bacteria could be turned into fatty acids that could react into biodiesel. Two types of bacteria are under further development by Biotit Scientific Biotechnology Laboratory in Seville, Spain: E. coli and Firmicutes. The Ecofa process also produces methane gas, and inconvertible solids that can be used as a soil amendment or fertilizer. "There is a huge variety of bacteria," Angulo said. "Currently, [biodiesel producers] receive a fat that must be processed through transesterification into biodiesel, but we are also working on other types of bacteria that are capable of producing fatty acids with the same characteristics as biodiesel." He said this would eventually allow producers to skip the transesterification step.
Ecofasa may avoid the ongoing food-versus-fuel debate and its expected successor, indirect land use, with its Ecofa process. "It would not be necessary to use specific fields of maize, wheat, barley, beets, etc., which would remain for human consumption without creating distortions or famines with unforeseeable consequences," the company stated in a press release. "This microbial technique can be extended to other organic debris, plants or animals, such as those contained in urban sewage. You can even experiment with other carbon sources, and this opens up a lot of possibilities. It is only necessary to find the appropriate bacteria."
The company created its name by combining the term "eco-combustible" with F.A., the initials of the inventor.
"Today we feel that we can produce between one and two liters [of biodiesel] per 10 kilograms of trash," Angulo said. That's a little more than one-fourth to one-half of a gallon for every 22 pounds of trash-or between 24 and 48 gallons per ton of urban waste. "We are working to improve that," he said.