Featured Research

from universities, journals, and other organizations

New Portable Energy Source Utilizes Microbes To Turn Electricity Directly To Methane

Date:
March 30, 2009
Source:
Penn State
Summary:
A tiny microbe can take electricity and directly convert carbon dioxide and water to methane, producing a portable energy source with a potentially neutral carbon footprint, according to engineers. The process does not sequester carbon, but it does turn carbon dioxide into fuel, according to researchers.

This photo shows Bruce E. Logan, Shaoan Cheng and Defeng Xing with a microbial cell that produces methane directly from electricity.
Credit: Bruce Logan's Lab, Penn State

A tiny microbe can take electricity and directly convert carbon dioxide and water to methane, producing a portable energy source with a potentially neutral carbon footprint, according to a team of Penn State engineers.

"We were studying making hydrogen in microbial electrolysis cells and we kept getting all this methane," said Bruce E. Logan, Kappe Professor of Environmental Engineering, Penn State. "We may now understand why."

Methanogenic microorganisms do produce methane in marshes and dumps, but scientists thought that the organisms turned hydrogen or organic materials, such as acetate, into methane. However, the researchers found, while trying to produce hydrogen in microbial electrolysis cells, that their cells produced much more methane than expected.

"All the methane generation going on in nature that we have assumed is going through hydrogen may not be," said Logan. "We actually find very little hydrogen in the gas phase in nature. Perhaps where we assumed hydrogen is being made, it is not."

Microbial electrolysis cells do require an electrical voltage to be added to the voltage that is produced by bacteria using organic materials to produce current that evolves into hydrogen. The researchers found that the Archaea, using about the same electrical input, could use the current to convert carbon dioxide and water to methane without any organic material, bacteria or hydrogen usually found in microbial electrolysis cells.

"We have a microbe that is self perpetuating that can accept electrons directly, and use them to create methane," said Logan.

Logan, working with Shaoan Cheng, senior research associate; Defeng Xing, post doctoral researcher, and Douglas F. Call, graduate student, environmental engineering, confirmed that the microscopic organisms produced the methane. The researchers created a two-chambered cell with an anode immersed in water on one side of the chamber and a cathode in water, inorganic nutrients and carbon dioxide on the other side of the chamber. They applied a voltage, but recorded only a minute current. The researchers then coated the cathode with the biofilm of Archaea and not only did current flow in the circuit, but the cell produced methane.

"The only way to get current at the voltage we used was if the microbes were directly accepting electrons," said Logan. He notes that the electrochemical reaction takes place without any precious metal catalysts and at a lower energy level than converting carbon dioxide to methane using conventional, non-biological methods.

The cells are about 80 percent efficient in converting electricity to methane and because they use carbon dioxide as feed stock, would be carbon neutral if the electricity comes from a non-carbon source such as solar or wind power.

"The process does not sequester carbon, but it does turn carbon dioxide into fuel," said Logan. "If the methane is burned and carbon dioxide captured, then the process can be carbon neutral."

Logan suggests the method for off peak capture of renewable energy in a portable fuel. Methane is preferred over hydrogen because a large portion of the U.S. infrastructure is already set up to easily transport and deliver methane.

These findings are reported in this week's issue of Environmental Science and Technology. The National Science Foundation and Air Products and Chemicals, Inc. supported this project.


Story Source:

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


Journal Reference:

  1. Shaoan Cheng, Defeng Xing, Douglas F. Call and Bruce E. Logan. Direct Biological Conversion of Electrical Current into Methane by Electromethanogenesis. Environ. Sci. Technol., 2009 [link]

Cite This Page:

Penn State. "New Portable Energy Source Utilizes Microbes To Turn Electricity Directly To Methane." ScienceDaily. ScienceDaily, 30 March 2009. <www.sciencedaily.com/releases/2009/03/090330111257.htm>.
Penn State. (2009, March 30). New Portable Energy Source Utilizes Microbes To Turn Electricity Directly To Methane. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2009/03/090330111257.htm
Penn State. "New Portable Energy Source Utilizes Microbes To Turn Electricity Directly To Methane." ScienceDaily. www.sciencedaily.com/releases/2009/03/090330111257.htm (accessed July 31, 2014).

Share This




More Earth & Climate News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Waves In Arctic Ocean Threaten Polar Ice

Big Waves In Arctic Ocean Threaten Polar Ice

Newsy (July 30, 2014) Big waves in parts of the Arctic Ocean are unprecedented, mainly because they used to be covered in ice. Video provided by Newsy
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (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
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) 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:
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