BioDieselNow - Renewable biodiesel fuel

New process improves biodiesel yields

Filed from Singapore 12/27/2007 9:40:33 AM GMT

USA:  Chemical engineering researchers at the University of Arkansas are developing a new process that will reduce the costs in converting animal fats and agricultural by-products into biodiesel.  The chemical process, known as supercritical methanol treatment, is said to be capable of drawing biodiesel at a yield of greater than 90 per cent from converted tall oil fatty acid, which is a major by-product of the wood-pulping process.

The researchers at the University Arkansas believe the new process holds a key to unlock the commercial viability of converting low-cost feedstocks and other agricultural by-products into biodiesel.  The process will enable biodiesel producers to move on from the use of more popular and expensive feedstocks, palm oil and soybean, which are recently trading at record highs on the commodity markets.

Previous efforts, including a study two years earlier at the university, to make biodiesel out of low-cost feedstocks, as opposed to refined oils, have used one of two conventional methods, base-catalyzed or acid-catalyzed esterification.  Although successful at producing biodiesel, these conventional methods struggle to be economically feasible due to long reaction times, excessive amounts of methanol required and/or undesired production of soaps during processing.

The researchers are now able to reduce the loss of yield and avoid soap formation as the new process, the supercritical methanol treatment works to dissolve the feed material and eliminate the need for the base catalyst.  The research is now conducted using low-grade chicken fat donated by Tyson Foods and tall oil fatty acids provided by Georgia Pacific.