$600,000 study looks at turning plant waste into biofuels

Guelph, ON – The growing demand for ethanol has Canadian farmers harvesting corn kernels at a rapid pace, but the rest of the plant has been going to waste, until now. Three scientists from the University of Guelph have teamed up to investigate how to turn corn husks, stalks and leaves as well as straw, switchgrass and even wood chips into usable biofuels.

Their three-year $600,000 study examines how to break down the plant cellulose and unlock the biofuels from the wasted biomass.

“Making ethanol from plant cellulose would offer an alternative to using food crops to produce energy as well as a lucrative use for waste biomass,” says Dr Anthony Clarke, department of molecular and cellular biology, who is working on the project with physicist Dr John Dutcher and chemist Dr Jacek Lipkowski.

Cellulose ethanol is made by treating fibre with enzymes to yield sugars that are then fermented to ethanol for fuel. But, turning plant cellulose into ethanol is more difficult than the process used for corn ethanol, and finding ways to make this process more efficient has become like “the holy grail of agriculture,” says Dr Dutcher.

The densely packed cellulose fibres are what lend plants their toughness, allowing a tree to grow hundreds of feet high without falling over. Although the inflexibility of the cellulose makes it difficult to break down, there are natural enzymes that can degrade the plant structure. Cows, for example, can digest the plant fodder because their guts contain specially evolved microbes able to gnaw through cellulose.

The researchers hope to copy this natural breakdown right down to the molecular level by combining a range of expertise and tools, from genetically engineered microbial enzymes to nanoscale microscopy and imaging.

By learning how nature breaks down cellulose in biomass and improving on that process, they hope to help the biofuels industry make a product that’s greener and more economically viable, says Dr Clarke.