US Scientists Improve Method to Produce SAF from Soyabean Oil

Scientists with the United State Department of Agriculture’s (USDA) chief scientific in-house research agency, the Agricultural Research Service (ARS), have improved the method of producing sustainable aviation fuel (SAF) from soyabean oil, the ARS announced last November  22. 
Presently, SAF derived from soyabean oil contained insufficient amounts of “aromatic” compounds, which give density to fuel and help keep engine seals supple and working properly, according to Ken Doll, research chemist with the ARS National Center for Agricultural Utilization Research in Peoria. For this reason, less SAF derived from soyabean oil could be blended with conventional petroleum-based jet fuels, Doll said.  One current method of making SAF from soyabean oil used the precious metal ruthenium to catalyze reactions that chemically modify the structure and properties of the oils’ unsaturated fatty acids, Doll explained. However, this method generated too few aromatic compounds, he said. 
To overcome the problem, Doll and fellow ARS scientists Bryan Moser and Gerhard Knothe replaced ruthenium with iridium as the chief catalyst in a six-step procedure that they devised and patented in November. In laboratory-scale experiments, use of the method on high oleic-acid soyabean oil had produced jet fuel formulations containing 8% to 35% aromatics - a range compatible with conventional jet fuels and beyond the range ruthenium-based methods could achieve, the ARS said.