Featured Research

from universities, journals, and other organizations

Pretreatment, proper harvest time boost ethanol from switchgrass

Date:
September 7, 2011
Source:
Purdue University
Summary:
Adding a pretreatment step would allow producers to get more ethanol from switchgrass harvested in the fall, according to a new study.

Adding a pretreatment step would allow producers to get more ethanol from switchgrass harvested in the fall, according to a Purdue University study.

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.


Story Source:

The above story is based on materials provided by Purdue University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Youngmi Kim, Nathan S. Mosier, Michael R. Ladisch, V. Ramesh Pallapolu, Y.Y. Lee, Rebecca Garlock, Venkatesh Balan, Bruce E. Dale, Bryon S. Donohoe, Todd B. Vinzant, Richard T. Elander, Matthew Falls, Rocio Sierra, Mark T. Holtzapple, Jian Shi, Mirvat A. Ebrik, Tim Redmond, Bin Yang, Charles E. Wyman, Ryan E. Warner. Comparative study on enzymatic digestibility of switchgrass varieties and harvests processed by leading pretreatment technologies. Bioresource Technology, 2011; DOI: 10.1016/j.biortech.2011.06.054

Cite This Page:

Purdue University. "Pretreatment, proper harvest time boost ethanol from switchgrass." ScienceDaily. ScienceDaily, 7 September 2011. <www.sciencedaily.com/releases/2011/08/110831160046.htm>.
Purdue University. (2011, September 7). Pretreatment, proper harvest time boost ethanol from switchgrass. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2011/08/110831160046.htm
Purdue University. "Pretreatment, proper harvest time boost ethanol from switchgrass." ScienceDaily. www.sciencedaily.com/releases/2011/08/110831160046.htm (accessed July 31, 2014).

Share This




More Matter & Energy News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) Video provided by AP
Powered by NewsLook.com
U.K. To Allow Driverless Cars On Public Roads

U.K. To Allow Driverless Cars On Public Roads

Newsy (July 30, 2014) Driverless cars could soon become a staple on U.K. city streets, as they're set to be introduced to a few cities in 2015. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins