New process turns chicken fat into biodiesel
December 20, 2007
"Major oil companies are already examining biodiesel as an alternative to petroleum," said R.E. "Buddy" Babcock, professor of chemical engineering. "With the current price of petroleum diesel and the results of this project and others, I think energy producers will think even more seriously about combining petroleum-based diesel with a biodiesel product made out of crude and inexpensive feedstocks."
Babcock says the yield from the process — termed supercritical methanol treatment — is greater than 90 percent.
"Supercritical methanol treatment dissolves and causes a reaction between components of a product — in this case, chicken fat and tall oil — by subjecting the product to high temperature and pressure," explained a statement from the University of Arkansas. "Substances become "supercritical" when they are heated and pressurized to a critical point, the highest temperature and pressure at which the substance can exist in equilibrium as a vapor and liquid. The simple, one-step process does not require a catalyst.
University of Arkansas graduate student Brent Schulte worked with this batch of tall oil fatty acid.
The development offers an alternative to biodiesel developed from refined vegetable oils, such as soybean, rapeseed, and palm oil, which are expensive and increasingly blamed for environmental problems. Babcock says that the high costs of vegetable feedstocks mean that biodiesel cannot compete with petroleum diesel unless the per-gallon price of diesel remains higher than $3. Using less refined and less-expensive feedstocks can make biodiesel more competitive with conventional diesel, but with fewer greenhouse gas emissions.
"Biodiesel provides an effective, sustainable-use fuel with many desirable properties," said University of Arkansas graduate student Brent Schulte. "In addition to being a renewable, biodegradable and carbon-neutral fuel source, it can be formed in a matter of months from feedstocks produced locally, which promotes a more sustainable energy infrastructure. It also decreases dependence on foreign oil and creates new labor and market opportunities for domestic crops."