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The language of change are like the pixels that form an image. Thus, the
landfill industry is in the process of defining itself as a "green energy"
contributor to our society . and we all know how warm and fuzzy that idea is
This recent article (below) paints the picture for the public of what the
landfill industry wants a "bioreactor" to be viewed as. They have the EPA
in their corner supporting them, and they will probably get the majority of
the DNR's across the nation to support them as well because they are
painting a pretty picture here. a solution that doesn't make anyone change
their lifestyles . a solution that makes the problem go away AND produce a
social good . green energy. Plus, it appears to be a genuine improvement
over the dry-tomb landfill (and that is another issue I think we need to
discuss later). We have our work cut out for us if we are to be successful
in keeping the bioreactor landfill from hurting the Zero Waste future
society we all envision.
I want to create a list of the "Top Five Reasons the Bioreactor is a Trojan
Horse" . in other words, it may look like a gift, but in fact hidden from
view are the following threats. and on top of my list is
(1) the "Life-cycle methane capture rate" . is it really only 20% with the
best available technology today? If so, then I think we should be calling
bioreactors "GHG Belching Machines";
Anyone else have any candidates for the Top Five list?
<http://columbiamissourian.com/> Columbia Missourian
Whiff of green energy lurks in city landfill
Plans call for first landfill bioreactor in Missouri
By STEVE BARTEL
February 12, 2007
How a bioreactor landfill works
According to the U.S. Environmental Protection Agency, a bioreactor landfill
is one that "operates to rapidly transform and degrade organic waste." In a
traditional landfill, waste is dumped into a "dry tomb," covered and allowed
to decompose naturally in the absence of oxygen, which inhibits the process.
The anaerobic bioreactor proposed for the Columbia landfill will use the
same system but inject 40,000 to 50,000 gallons of water per day into the
tomb, called a "cell." The water will be recirculated through the cell to
facilitate the growth of bacteria that will rapidly decompose organic
material such as paper, food scraps and wood, freeing up more space for
incoming waste and producing more methane, which can be used as fuel.
There are plenty of places to find cutting-edge research and technology in
Columbia. One place you might not think to look, however, is inside a giant
pile of trash.
Columbia is expected to finalize a contract this week with Jefferson City's
Frank Twehous Excavating Co. to begin construction on what could become the
first landfill bioreactor in Missouri. At nearly $1.6 million, Twehous' bid
is about $260,000 less than the closest competitor, Fretco Inc. of
The methane gas produced by the bioreactor and existing traditional fills is
estimated to account for about 2.5 percent of Columbia's energy needs in 10
years, when the facility would be operating at full capacity.
The methane would be converted into about 17,010 megawatts of electricity
per year, or enough to power 1,739 homes.
"This has been a project that's been on the table since 2000," said Richard
Wieman, solid waste utility manager at the Columbia Sanitary Landfill. "It's
designed to study how well (bioreactor technology) works or doesn't work."
Other bioreactors, such as those located at the Waste Management-Outer Loop
Landfill in Louisville, Ky., have seen considerable success. The Kentucky
facility opened its first two bioreactors in 2000 and has since added three
more, covering over 40 acres and capable of holding a total of 5 million
tons of trash. Using 130 wellheads and a new experimental collection system
called multi-plane, the facility captures about 3,600 cubic feet of natural
gas per minute, which is used to heat a nearby General Electric
manufacturing plant.Gary Hater, bioreactor program director at the
Louisville facility, saw his operations personnel assume management of the
on-site bioreactors from the research team just last year.
"We've progressed out of the experimental stage," he said. "It's working
well with operations personnel, and we're at a point where we're making sure
our operations are correct. This is proof that this system is doable."
Starting a bioreactor isn't as easy as digging a hole and filling it with
water and trash. There are certain risks associated with any landfill,
including the escape of gas, stability issues due to the shifting of
decomposing material, and leachate, potentially hazardous liquid that could
breach the liner at the bottom of the landfill and enter the water supply.
The Missouri Department of Natural Resources is responsible for approving
the design and construction of a new landfill to ensure it meets
environmental safety standards. Because this project is the first of its
kind in Missouri, no such procedure existed for bioreactors until Jan. 16 of
this year, when the federal Environmental Protection Agency approved the
DNR's authority to allow the bioreactor in Columbia.
"We're learning, in a way," said Jim Hull, director of the DNR's Solid Waste
Management Program. "We've never approved a bioreactor before. The main
things we're looking for are an appropriate site and an acceptable design."
Hull expects the permit request from the city "any time," and has sent
members of his staff to bioreactor design training and on tours of
bioreactor sites in other states to prepare them for the review of the
Columbia design. When the application is received, a team of engineers,
hydrologists and soil experts will have up to six months to approve or
reject the design proposed by Camp, Dresser & McKee Inc., the Cambridge,
Mass.-based consulting firm hired by Columbia to oversee planning and
construction of the bioreactor.
The proposed bioreactor would also be a first for Lisa Harrison, the CDM
project manager in charge of the bioreactor design and construction.
Harrison expects to have the landfill cell- the earthen construction that
holds the trash - finished by the end of this summer, at which point waste
and high-density polyethylene piping would begin to fill the dry tomb. After
about two years of trash has accumulated, pending DNR approval, water would
begin flowing through the pipes and the decomposition rate would rapidly
increase, if everything goes as planned.
John Bowders, of the MU Department of Civil Engineering, said the effect of
water-aided decomposition can be dramatic.
Settlement, the reduction of the amount of waste in a cell, is usually
around 5 percent to 20 percent over 30 years in a dry tomb. When a
bioreactor is activated, the settlement figures can be from 30 percent to 50
percent over five to 10 years. That means the height of accumulated waste in
a cell could be reduced from 100 feet to as little as 50 feet in a few
The decomposing waste in a landfill cell doesn't just disappear, however.
The organic material is converted into a problem that has plagued landfill
operators for a long time - natural gas.
>From trash to useful gas
Zhiqiang Hu of the MU Department of Civil and Environmental Engineering said
that although it is difficult to name all the bacteria involved in landfill
decomposition, the primary group is called methanogens. As they break down
organic material, methanogens produce methane, a greenhouse gas 20 times
more potent than carbon dioxide and a major factor in climate change,
according to the EPA. Due to the accelerated rate of decomposition in a
bioreactor, methane gas is produced at a much higher rate than in dry tomb
landfills, which already are the primary source of human-related methane
emissions in the U.S.
The Columbia Sanitary Landfill is equipped with technology enabling the
capture of landfill gas, preventing damage to the environment and providing
an opportunity for a new fuel source. The landfill has been collecting
methane since 1994, but not in sufficient volumes to produce electricity.
The methane is currently burnt off, or flared.
"It's simply a matter of getting enough garbage in place to make (methane
collection) an economical project," Wieman said.
With the continued filling of existing cells and the possible increase in
methane production from the proposed bioreactor, Columbia would stand ready
to harness the natural gas as an alternative source of energy. The new
design can accommodate four engines capable of converting the captured gas
into electricity. Wieman plans to start with two engines and add more as the
rising level of stored waste produces more gas. Coupled with the city's
recent agreement to purchase electricity produced from natural gas at the
dry tomb landfill in Jefferson City, this new source of fuel would put
Columbia well ahead of alternative energy goals mandated by voters in a 2004
If the plans receive DNR approval, Columbia will join a handful of cities
around the world in spearheading bioreactor technology.
"I see nothing in its way right now," Wieman said. "DNR has been very
positive. It's fun to be a part of this experiment and leading technology in
<http://columbiamissourian.com/news/print.php?ID=24180#top#top> back to the
Copyright C 2007 Columbia Missourian
Boulder, CO. USA
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