Biodiesel made from yellow oils such as used cooking, soybean, and canola oil is a hot commodity right now. Because of this, prices have skyrocketed (biodiesel is now priced comparably to petroleum-based fuel) and it has become more difficult to obtain the oils necessary for manufacturing. A professor of chemical engineering at the University of Connecticut believes it’s time to move on to the next frontier of biodiesel manufacturing: the use of brown grease from waste traps.
For the last few years, UCONN Professor Richard Parnas has been converting the school’s used cooking oils into biodiesel to be used by on-campus buses. But because of the rising price and lack of supply of yellow greases, Parnas and his company, RPM Sustainable Technologies, is now researching ways to turn brown grease – the thick, gunky stuff that collects at the bottom of traps in fryers and waste treatment facilities – into biodiesel, a monumental task given the makeup of the grease.
“Brown grease is the next frontier in the race to the bottom,” Parnas said. “Brown grease is just like it sounds, a fairly disgusting thing.”
Parnas and company are setting up a prototype system to split the collected brown grease into oils and biosolids, converting the oils into biodiesel fuel and the solids into synthetic natural gas to produce methanol. The company is seeking public and private funds for further development, and local waste treatment centers have expressed interest in the system.


