| Clipped from: Microbes turn electricity directly to methane |
Microbes turn electricity directly to methane
Shaoan Cheng and Defeng Xing (l to r) work with cell that produces methane directly from electricity by way of tiny microbes while Bruce E. Logan looks on.
(PhysOrg.com) -- 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.
| Clipped from: Bruce E. Logan |
Bruce E. Logan
Research in the Logan lab is focused on bioenergy production for the development of an energy-sustainable water infrastructure for both industrialized and developing countries. Using new technologies, it is possible to directly generate electricity using microbial fuel cells, or hydrogen gas using microbial electrolysis cells, from wastewaters and biomass. These systems have the potential not only to power the water infrastructure, but to produce net excess power for communities and industries.
| Clipped from: Bruce Logan Research - Microbial Fuel Cells |
Microbial fuel cells (MFCs)
How does a microbial fuel cell work? When bacteria are placed in the anode chamber of a specially-designed fuel cell that is free of oxygen, they attach to an electrode. Because they do not have oxygen, they must transfer the electrons that they obtain from consumption (oxidation) of their food somewhere else than to oxygen-- they transfer them to the electrode. In a MFC these electrons therefore go to the anode, while the counter electrode (the cathode) is exposed to oxygen. At the cathode the electrons, oxygen and protons combine to form only water. The two electrodes are at different potentials (about 0.5 V), creating a bio-batter (if the system is not refilled) or a fuel cell (if we constantly put in new food or "fuel" for the bacteria).
Check out the MFC-cam, our on-line demonstration of an MFC!
| Clipped from: Penn State Live - Microbes turn carbon dioxide into methane |
Microbes turn carbon dioxide into methane
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.
The National Science Foundation and Air Products and Chemicals, Inc. supported this project.
Sources:
- Microbes turn electricity directly to methane
- Bruce E. Logan
- Bruce Logan Research - Microbial Fuel Cells
- Penn State Live - Microbes turn carbon dioxide into methane
Related:
- New Portable Energy Source Utilizes Microbes To Turn Electricity Directly To Methane
- Bug eats electricity, farts biogas - tech - 05 April 2009 - New Scientist
- Microbes turn electricity directly to methane without hydrogen generation
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