Michael Ladisch, a distinguished professor of agricultural and biological engineering, and Youngmi Kim, a research scientist, compared switchgrass based on growing location, harvest time and whether it was given a pretreatment step. They found that location wasn't important, but the other two factors could significantly increase the amount of ethanol obtained from the feedstock.
"Switchgrass harvested in the spring had more cellulose, but also more lignin," said Kim, whose findings were published in the early online version of the journal Bioresource Technology. "You do not get the advantage of the increased cellulose content because it's more difficult to extract those sugars because of the lignin."
Lignin, a rigid substance found in plant cell walls, is one of the most significant problems with cellulosic ethanol production. Besides the harvest time, a pretreatment step - cooking switchgrass in hot water under pressure for about 10 minutes - would also help work around lignin.
Before pretreatment, Kim said about 10 percent of cellulose was converted to glucose, the yeast-fermentable sugar that produces ethanol. After pretreatment, that number jumped to as much as 90 percent. The pretreatment dissolves hemicellulose, which bonds cellulose and lignin in the plant. Once it is gone, there is more access to the sugars contained in the cellulose.
"There is more surface area for the enzymes to digest cellulose," Kim said.
Ladisch said advancements in techniques to work around lignin could make spring switchgrass more attractive. But he said that fall switchgrass given a pretreatment and fermentation with special yeast shows potential to give as much as 800-1,000 gallons of ethanol per acre per year, compared with 150-250 gallons per year without pretreatment. Ladisch said corn ethanol from grain produces about 500-600 gallons per acre per year.
"This shows that we can improve the processes and increase the amount of ethanol we get from switchgrass," Ladisch said.
Ladisch is chief technology officer at Mascoma, a renewable fuels company based in New Hampshire. He received no funding from the company for this research, which was supported by the U.S. Department of Energy.
The work is part of a concerted research effort on pretreatments by a consortium made up of the University of California Riverside, Auburn University, Texas A&M University, Michigan State University, Genencor and the National Renewable Energy Laboratory together with Purdue University.
Abstract on the research in this release is available at: http://www.purdue.edu/newsroom/research/2011/110831LadischSwitchgrass.html
Brian Wallheimer | EurekAlert!
Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory
Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine