A new innovative biomass pretreatment technology, co-solvent enhanced lignocellulosic fractionation (CELF), has been developed by researchers at the University of California, Riverside (UCR) to improve biofuel competitiveness with petroleum.
“Lignin utilization is the gateway to making what you want out of biomass in the most economical and environmentally friendly way possible,” said UC Riverside Associate Research Professor Charles Cai. “Designing a process that can better utilize both the lignin and sugars found in biomass is one of the most exciting technical challenges in this field.”
CELF, invented by professor Cai, enables better utilization of lignin, a main component of plant cell walls, in biorefinery operations. A study published in Energy & Environmental Science showcases the economic and environmental benefits of a CELF biorefinery compared to petroleum-based fuels and earlier biofuel production methods.
“CELF uses tetrahydrofuran or THF to supplement water and dilute acid during biomass pretreatment. It improves overall efficiency and adds lignin extraction capabilities,” Cai said. “Best of all, THF itself can be made from biomass sugars.”
The research collaboration involved UCR, the Center for Bioenergy Innovation managed by Oak Ridge National Laboratories, and the National Renewable Energy Laboratory, with funding from the U.S. Department of Energy’s Office of Science. The study considered ideal biomass feedstocks and lignin utilization. Second-generation biofuel operations use non-edible plant biomass, such as hardwood poplar, which, when processed through a CELF biorefinery, can yield sustainable aviation fuel at a break-even price of $3.15 per gallon of gasoline equivalent.
The U.S. Department of Energy estimates that up to a billion tons per year of biomass could be available for biofuel and bioproduct manufacturing in the United States, capable of displacing 30% of petroleum consumption and creating domestic jobs. The CELF biorefinery model also proposes producing renewable chemicals, such as bioplastics and food and drink flavoring compounds, contributing to a lower carbon footprint.
The Department of Energy’s Bioenergy Technology Office has awarded the researchers a $2 million grant to build a small-scale CELF pilot plant at UCR, with the hope that demonstrating its success will lead to larger-scale investment in the technology and contribute to reducing global warming caused by fossil fuel usage.
“I began this work more than a decade ago because I wanted to make an impact. I wanted to find a viable alternative to fossil fuels and my colleagues and I have done that,” Cai said. “Using CELF, we have shown it is possible to create cost-effective fuels from biomass and lignin and help curb our contribution of carbon emissions into the atmosphere.”
