Novozymes launches enzyme for biodiesel from corn, waste oils

By Susanne Retka Schill | December 03, 2014

Novozymes has launched a new enzyme, trademarked Eversa, for the conversion of lower-grade oils, such as waste cooking oil or corn oil, into biodiesel meeting the same trade specifications as biodiesel created through traditional chemical processing.  

“The flexibility of the enzymatic biodiesel process creates new opportunities for ethanol producers to optimize revenues from extracted corn oil by making biodiesel on site while also accepting waste greases from their local community,” said Frederik Mejby, Novozymes marketing director, grain processing. “The process can be easily bolted onto the back end of their existing facility with minimal additional CAPEX.”

Traditional chemical processing of biodiesel has been most suited for oils from soybeans, palm or rapeseed that typically contain less than 0.5 percent free fatty acids (FFA). Many existing biodiesel process designs have difficulty handling oils with higher FFA levels, even though those feedstocks are generally far more economical. “A small number of plants have been producing biodiesel from waste oils using existing technologies,” Mejby explained. “But this has not been cost-efficient until now, broadly speaking, as the waste oils have had to be refined before being processed using chemicals. We hope that our technology can unleash more of the potential in these lower-grade feedstocks.”

“The idea of enzymatic biodiesel is not new, but the costs involved have been too high for commercial viability,” Mejlby added. “Eversa changes this and enables biodiesel producers to finally work with waste oils and enjoy feedstock flexibility to avoid the pinch of volatile pricing.” Eversa works with a broad range of fatty materials as feedstock, but the initial focus has been on used cooking oil, DDGS corn oil and fatty acid distillates.

Other advantages for the enzymatic process include a lower energy requirement and the elimination of the chemical catalyst, sodium methoxide, one of the most hazardous chemicals in traditional biodiesel plants. “Switching to Eversa can lead to a safer working environment for plant operators. The enzymatic process does not use high pressure or high temperature,” Mejlby said. “And when it comes to the actual enzymes, their organic nature and mild process conditions do not generate toxic components as in some chemical biodiesel processes.”

For existing biodiesel producers, making the change from a chemical catalyst to the enzymatic process will require retrofitting. Novozymes’ engineering partners estimate that the resulting improved process economy indicates a payback time of three years or less, depending on the plant setup and feedstock savings potential in that region.

Marc Kellens, group technical director at biodiesel technology provider Desmet Ballestra said the enzymatic processing will likely prove popular with biodiesel producers. “The enzymatic process is simple and does not need much pretreatment. It is the best alternative for modifying existing plants to enable them to incorporate difficult-to-convert oils.”