Featured Research

from universities, journals, and other organizations

Carbon mitigation strategy uses wood for buildings first, bioenergy second

Date:
November 29, 2011
Source:
University of Washington
Summary:
A new study is first to focus on the extra carbon savings that can be squeezed from trees when wood not suitable for long-term building materials is used for bioenergy: Depending on the process used, ethanol from woody biomass emits less greenhouse gas than an equivalent amount of gasoline, between 70 percent and a little over 100 percent less. In contrast, corn ethanol reduces greenhouse gas emissions 22 percent on average.

Depending on the way it is made, and considering everything that goes into producing it and how it burns, ethanol from woody biomass emits 70 percent to slightly more than 100 percent less greenhouse gases than gasoline.
Credit: University of Washington

Proposals to remove the carbon dioxide caused by burning fossil fuel from the atmosphere include letting commercially managed forests grow longer between harvests or not cutting them at all.

Related Articles


An article published in the journal Forests says, however, that Pacific Northwest trees grown and harvested sustainably, such as every 45 years, can both remove existing carbon dioxide from the air and help keep the gas from entering the atmosphere in the first place. That's provided wood is used primarily for such things as building materials instead of cement and steel -- which require more fossil fuels in their manufacture -- and secondarily that wood wastes are used for biofuels to displace the use of fossil fuels.

"When it comes to keeping carbon dioxide out of the atmosphere, it makes more sense to use trees to recycle as much carbon as we can and offset the burning of fossil fuel than it does to store carbon in standing forests and continuing burning fossil fuels," said Bruce Lippke, University of Washington professor emeritus of forest resources.

Lippke is one of eight co-authors of the article in Forests. It is the first to comprehensively calculate using woody biomass for bioenergy in addition to using wood for long-lived products. The article focuses on the extra carbon savings that can be squeezed from harvesting trees if wood not suitable for long-term building materials is used for bioenergy. Such wood can come from the branches and other debris left after harvesting, materials thinned from stands or from plantations of fast-growing trees like willow.

For the article, the co-authors looked at selected bioenergy scenarios using wood from the U.S. Pacific Northwest, Southeast and Northeast.

They considered two ways of producing ethanol from woody biomass -- gasification and fermentation -- and used what's called life cycle analysis to tally all the environmental effects of gathering, processing and using the resulting fuels. Ethanol from woody biomass emits less greenhouse gas than an equivalent amount of gasoline, between 70 percent and a little over 100 percent less.

How much of a reduction depends on the process. Achieving slightly more than a 100 percent reduction in greenhouse gas emissions is possible, for example, using a fermentation process that both produces ethanol and generates enough electricity to offset the fossil fuel used in the fermentation process.

In contrast, producing and using corn ethanol to displace gasoline reduces greenhouse gas emissions 22 percent on average, according to the Environmental Protection Agency's fact sheet "Greenhouse Gas Impacts of Expanded Renewable and Alternative Fuels Use."

While biofuels from woody biomass are carbon friendly, Lippke cautions that the U.S. should not use tax breaks or other incentives that inadvertently divert wood to bioenergy that is better used for long-lived building materials and furniture.

"Substituting wood for non-wood building materials can displace far more carbon emissions than using the wood for biofuel," the article says. "This fact creates a hierarchy of wood uses that can provide the greatest carbon mitigation for each source of supply."

Lippke said using wood for products and bioenergy can be considered carbon neutral because the carbon dioxide trees absorb while growing eventually goes back to the atmosphere when, for instance, wood rots after building demolition or cars burn ethanol made from woody debris. With sustainably managed forests, that carbon dioxide is then absorbed by the growing trees awaiting the next harvest.

The co-authors aren't advocating that all forests be harvested, just the ones designated to help counter carbon dioxide in the atmosphere. Older forests, for instance, provide ecological values even though they absorb less carbon dioxide as they age.

In the article the authors also urge policymakers and citizens to consider not just carbon mitigation but also to find ways to weigh the importance of energy independence from fossil fuels when considering how to use woody biomass for bioenergy.

"Simply burning woody biomass to generate heat or electricity makes sense for carbon mitigation," he says, "But there's no energy independence gained," Lippke said. So carbon efficiency is only one part of the equation. Transportation fuels depend heavily on imported oil and therefore biofuels that replace them make additional contributions to the domestic economy, including energy independence and rural economic development, the authors said.

Other co-authors are Richard Gustafson and Elaine Oneil with the UW, Richard Venditti with North Carolina State University, Timothy Volk with the State University of New York, Leonard Johnson with the University of Idaho, Maureen Puettmann of WoodLife Environmental Consultants and Phillip Steele with Mississippi State University.

The publication integrates findings across many previous reports generated by a consortium of 17 research institutions that have been involved in life cycle analysis of wood products for more than 15 years through the Consortium for Research on Renewable Industrial Materials, based at the UW. The recent biofuel life cycle research was funded with a grant from the U.S. Forest Service's Forest Products Laboratory.


Story Source:

The above story is based on materials provided by University of Washington. The original article was written by Sandra Hines, News and Information. Note: Materials may be edited for content and length.


Journal Reference:

  1. Bruce Lippke, Richard Gustafson, Richard Venditti, Timothy Volk, Elaine Oneil, Leonard Johnson, Maureen Puettmann, Phillip Steele. Sustainable Biofuel Contributions to Carbon Mitigation and Energy Independence. Forests, 2011; 2 (4): 861 DOI: 10.3390/f2040861

Cite This Page:

University of Washington. "Carbon mitigation strategy uses wood for buildings first, bioenergy second." ScienceDaily. ScienceDaily, 29 November 2011. <www.sciencedaily.com/releases/2011/11/111122143356.htm>.
University of Washington. (2011, November 29). Carbon mitigation strategy uses wood for buildings first, bioenergy second. ScienceDaily. Retrieved December 18, 2014 from www.sciencedaily.com/releases/2011/11/111122143356.htm
University of Washington. "Carbon mitigation strategy uses wood for buildings first, bioenergy second." ScienceDaily. www.sciencedaily.com/releases/2011/11/111122143356.htm (accessed December 18, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Thursday, December 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Arctic Warming Twice As Fast As Rest Of Planet

Arctic Warming Twice As Fast As Rest Of Planet

Newsy (Dec. 18, 2014) The Arctic is warming twice as fast as the rest of the planet, thanks in part to something called feedback. Video provided by Newsy
Powered by NewsLook.com
Ivory Trade Boom Swamps Law Efforts

Ivory Trade Boom Swamps Law Efforts

Reuters - Business Video Online (Dec. 17, 2014) Demand for ivory has claimed the lives of tens of thousands of African elephants and now a conservation report says the illegal trade is overwhelming efforts to enforce the law. Amy Pollock reports. Video provided by Reuters
Powered by NewsLook.com
Indictments in West Virginia Chemical Spill Case

Indictments in West Virginia Chemical Spill Case

AP (Dec. 17, 2014) A grand jury indicted four former executives of Freedom Industries, the company at the center of the Jan. 9, 2014 chemical spill in Charleston, West Virginia. The spill contaminated the Elk River and the water supply of 300,000 people. (Dec. 17) Video provided by AP
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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