It appears that this technology is about to be mastered. It is a
clear winner over present technology and produces some power as a
bonus. If the present protocol consumes 3% of power out put and this
approach produces 1% of power output, it converts into a 4% swing to
the good in power availability.
All plant must be replaced sometime so this development is obvious
welcome.
It is not the power that matters here, it is the superior methodology
that eliminates nasty gases and produces a salable byproduct. The
present solution is actually good enough, but this is superior and
thus welcome while at the same price point.
Major Advance in
Generating Electricity From Wastewater
January 24, 2013
Aaron Jackson
Engineers at Oregon
State University have made a breakthrough in the performance of
microbial fuel cells that can produce electricity directly
from wastewater, opening the door to a future in which waste
treatment plants not only will power themselves, but will sell excess
electricity.
The new
technology developed at OSU uses new concepts —
reduced anode-cathode spacing, evolved microbes and new separator
materials — and can produce more than two kilowatts per cubic
meter of liquid reactor volume — 10 to 50 more times the
electrical per unit volume than most other approaches using microbial
fuel cells, and 100 times more electricity than some.
This technology cleans
sewage by a very different approach than the aerobic bacteria used in
the past. Bacteria oxidize the organic matter and, in the process,
produce electrons that run from the anode to the cathode within the
fuel cell, creating an electrical current.
Almost any type of
organic waste material can be used to produce electricity — not
only wastewater, but also grass straw, animal waste, and byproducts
from such operations as the wine, beer or dairy industries.
The researchers say
this could eventually change the way that wastewater is treated
all over the world, replacing the widely used “activated sludge”
process that has been in use for almost a century. The new
approach would produce significant amounts of electricity while
effectively cleaning the wastewater, they suggest.
“If this technology
works on a commercial scale, the way we believe it will, the
treatment of wastewater could be a huge energy producer, not a huge
energy cost,” said Hong Liu, an associate professor in the OSU
Department of Biological and Ecological Engineering. “This could
have an impact around the world, save a great deal of money, provide
better water treatment and promote energy sustainability.”
Experts estimate that about 3 percent of the electrical energy
consumed in the United States and other developed countries is used
to treat wastewater, and a majority of that electricity is produced
by fossil fuels.
The system also works
better than an alternative approach to creating electricity from
wastewater that is based on anaerobic digestion that produces
methane. It treats the wastewater more effectively, and doesn’t
have any of the environmental drawbacks of that technology, such as
production of unwanted hydrogen sulfide or possible release of
methane, a potent greenhouse gas, the researchers believe.
The OSU system has
now been proven at a substantial scale in the laboratory, Liu
said, and the next step would be a pilot study. A good candidate, she
said, might initially be a food processing plant, which is a
contained system that produces a steady supply of certain types of
wastewater that would provide significant amounts of electricity.
Once advances are made
to reduce high initial costs, researchers estimate that the
capital construction costs of this new technology should be
comparable to that of the activated sludge systems now in widespread
use today — and even less expensive when future sales of
excess electricity are factored in.
The approach may also
have special value in developing nations, where access to electricity
is limited and sewage treatment at remote sites is difficult or
impossible as a result.
The ability
of microbes to produce electricity has been known for
decades, but only recently have technological advances made their
production of electricity high enough to be of commercial use. OSU
researchers reported several years ago on the promise of this
technology, but at that time the systems in use produced far less
electrical power. Continued research should also find even more
optimal use of necessary microbes, reduced material costs and
improved function of the technology at commercial scales, OSU
scientists said.
REFERENCES:
- Yanzhen Fan, Sun-Kee Han, Hong Liu, Improved performance of CEA microbial fuel cells with increased reactor size,Energy & Environmental Science, 2012, DOI: 10.1039/C2EE21964F
About the Author
Aaron Jackson is a
writer for the excellent site, Exposing The Truth. Please
visit them on Facebook, here.
This article is
offered under Creative Commons license. It’s okay to republish it
anywhere as long as attribution bio is included and all links remain
intact.
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