How to Make It Easier to Turn Plant Waste into Biofuels

by Todd Bates (Rutgers University/Phys.Org) Researchers have developed a new process that could make it much cheaper to produce biofuels such as ethanol from plant waste and reduce reliance on fossil fuels.

Their approach, featuring an ammonia-salt based solvent that rapidly turns plant fibers into sugars needed to make ethanol, works well at close to room temperature, unlike conventional processes, according to a Rutgers-led study in the journal Green Chemistry.

"Our pretreatment system can slash—by up to 50-fold—the use of enzymes to turn solvent-treated cellulose (plant fiber) into glucose (a sugar) used to make bioproducts like ethanol," said lead author Shishir P. S. Chundawat, an assistant professor in the Department of Chemical and Biochemical Engineering in the School of Engineering at Rutgers University-New Brunswick. "Similar processes could greatly reduce the cost of producing biofuels from waste biomass like corn stalks and leaves."

The solvent can also extract more than 80 percent of the lignin in plant waste. Lignin, which binds to and fortifies plant fibers, could be used to help upgrade valuable aromatic chemicals in the future, according to Chundawat. The research benefited from collaborative efforts and access to a high-tech Bio-SANS instrument at Oak Ridge National Laboratory for analysis of how complex biological systems like plant waste respond during processing to better understand how cellulose is dissolved at a molecular level.

Next steps will be to optimize the pretreatment process for biomass like corn stover, municipal solid wastes and bioenergy crops like switchgrass and poplar that could be turned into fuels, while also developing more robust enzymes to further reduce costs, according to Chundawat. READ MORE