Sound idea for making plant biofuels

Research by David Grewell, associate professor of agricultural and biosystems engineering, and his colleagues Melissa Montalbo-Lomboy and Priyanka Chand, have shown that pretreating a wide variety of feedstocks - including switch grass, corn stover, and soft wood - with ultrasound consistently enhances the chemical reactions necessary to convert the biomass into high-value fuels and chemicals.

The team will present its findings at the 21st International Congress on Acoustics (ICA 2013), held June 2-7 in Montreal.

The Iowa State researchers found they could significantly increase the efficiency of removing lignin from biomass in solution. Lignin is the chemical compound that binds cellulose and hemicellulose together in plant cell walls.

Commonly, enzymes or chemicals are used to remove it from biomass and allow the freed sugars to be dissolved for further processing into biofuel.

Grewell and his colleagues found that pretreating instead with ultrasound makes lignin removal so efficient that sugar dissolution occurs in minutes rather than the hours needed with traditional mixing systems.