Featured Research

from universities, journals, and other organizations

Simpler Way To Counter Global Warming Explained: Lock Up Carbon In Soil And Use Bioenergy Exhaust Gases For Energy

Date:
May 12, 2007
Source:
Cornell University
Summary:
Writing in the journal Nature, a Cornell biogeochemist describes an economical and efficient way to help offset global warming: Pull carbon dioxide out of the atmosphere by charring, or partially burning, trees, grasses or crop residues without the use of oxygen. When bioenergy is produced by pyrolysis (low-temperature burning without oxygen), it produces biochar, which has twice as much carbon in its residue than that from other sources. This makes bioenergy carbon-negative and improves soil health.

When bioenergy is produced by pyrolysis (low-temperature burning without oxygen), it produces biochar, which has twice as much carbon in its residue than that from other sources. This makes bioenergy carbon-negative and improves soil health.
Credit: Image courtesy of Cornell University

Writing in the journal Nature, a Cornell biogeochemist describes an economical and efficient way to help offset global warming: Pull carbon dioxide out of the atmosphere by charring, or partially burning, trees, grasses or crop residues without the use of oxygen.

When bioenergy is produced by pyrolysis (low-temperature burning without oxygen), it produces biochar, which has twice as much carbon in its residue than that from other sources. This makes bioenergy carbon-negative and improves soil health.

This process, he writes, would double the carbon concentration in the residue, which could be returned to the soil as a carbon sink. The exhaust gases from this process and other biofuel production could then be converted into energy.

This so-called biochar sequestration could offset about 10 percent of the annual U.S. fossil-fuel emissions in any of several scenarios, says Johannes Lehmann, associate professor of soil biogeochemistry in the Department of Crop and Soil Sciences at Cornell.

"Biochar sequestration, combined with bioenergy production, does not require a fundamental scientific advance, and the underlying production technology is robust, clean and simple, making it appropriate for many regions of the world," said Lehmann. "It not only reduces emissions but also sequesters carbon, making it an attractive target for energy subsidies and for inclusion in the global carbon market."

Most plants pull carbon dioxide out of the atmosphere and lock it up in their biomass or in soil organic matter. But taking this a step further, Lehmann recommends heating the plant biomass without oxygen in a process known as low-temperature pyrolysis. When returned to the soil, biochar creates a stable, long-term carbon sink.

"Biochar also has been shown to improve the structure and fertility of soils, to enhance the retention and efficiency of fertilizers as well as to improve the productivity of soil," said Lehmann.

Capturing the exhaust gases from the pyrolysis process produces energy in such forms as heat, electricity, bio-oil or hydrogen. By adding the biochar to soil rather than burning it as an energy source (which most companies do), bioenergy can be turned into a carbon-negative industry. Biochar returned to soil not only secures soil health on bioenergy plantations but also reduces greenhouse gas emissions by an additional 12 to 84 percent.

Compared with ethanol production, pyrolysis that produces biochar and bioenergy from its exhaust gases is much less expensive, Lehmann said, when the feedstock is animal waste, clean municipal waste or forest residues collected for fire prevention.

Lehmann said that as the value of carbon dioxide increases on carbon markets, "we calculate that biochar sequestration in conjunction with bioenergy from pyrolysis becomes economically attractive when the value of avoided carbon dioxide emissions reaches $37 per ton." Currently, the Chicago Climate Exchange is trading carbon dioxide at $4 a ton; it is projected that that the price will rise to $25-$85 a ton in the coming years.


Story Source:

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


Cite This Page:

Cornell University. "Simpler Way To Counter Global Warming Explained: Lock Up Carbon In Soil And Use Bioenergy Exhaust Gases For Energy." ScienceDaily. ScienceDaily, 12 May 2007. <www.sciencedaily.com/releases/2007/05/070511211255.htm>.
Cornell University. (2007, May 12). Simpler Way To Counter Global Warming Explained: Lock Up Carbon In Soil And Use Bioenergy Exhaust Gases For Energy. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2007/05/070511211255.htm
Cornell University. "Simpler Way To Counter Global Warming Explained: Lock Up Carbon In Soil And Use Bioenergy Exhaust Gases For Energy." ScienceDaily. www.sciencedaily.com/releases/2007/05/070511211255.htm (accessed October 22, 2014).

Share This



More Earth & Climate News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) — The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Trick-or-Treating Banned Because of Polar Bears

Trick-or-Treating Banned Because of Polar Bears

Buzz60 (Oct. 21, 2014) — Mother Nature is pulling a trick on the kids of Arviat, Canada. As Mara Montalbano (@maramontalbano) tells us, the effects of global warming caused the town to ban trick-or-treating this Halloween. Video provided by Buzz60
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

Newsy (Oct. 20, 2014) — The United Nations says water is a human right, but should it be free? Detroit has cut off water to residents who can't pay, and the U.N. isn't happy. 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:

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