Capturing Carbon – Part
I
Burning coal to generate electricity is one of our planet’s major sources
of carbon emissions – the primary gas blamed for global warming. Producing
electricity with coal is therefore one of the pivotal issues in the conflict
between our energy needs and our environmental needs.
According to a recent feature in The National Geographic,
the U.S, China and India plan to build 850 new coal-fired
plants by 2012. Combined, these plants will spew five times
as much carbon dioxide into the atmosphere as the Kyoto Protocol
nations aim to eliminate.
It is clear that we cannot keep going in same the direction
as we have in past, yet what are our options?
Many people are arguing for the abolishment of coal production
altogether. Others counter that - like it or not - coal is
here to stay, and we need to be using new technology to “clean” up
the production of it, either by sequestering the carbon emissions
for storage, or finding innovative ways to recycle CO2.
Carbon sequestration (CSS), a process where carbon dioxide
emissions from smokestacks are trapped and then stored underground,
is considered by a growing number of advocates to be the
best solution if we continue to produce electricity derived
from coal.
According to a report released by the Intergovernmental
Panel on Climate Change (IPCC) in 2005, carbon sequestration
could reduce C02 emissions into the atmosphere by approximately
80 to 90 percent, compared to a plant not using some type
of CSS technology.
Critics question the cost and feasibility (ie. gas leakage)
of carbon sequestration, yet many studies indicate that these
fears are unfounded.
The latest research, released this month by The National
Environmental Research Council (NERC), has revealed that
storing carbon dioxide beneath the earth may be a safer and
longer term method of reducing emissions in the atmosphere
than previously thought.
NERC-funded researchers at the University of Manchester found that carbon dioxide
has been naturally stored for up to 40 million years in CO2 gas fields in the
Colorado Plateau and Rocky Mountains of the USA.
Dr. Stuart Gilfillan, the researcher running the project,
said in a press release that he hopes this study will pave
the way for C02 storage in both the UK and abroad.
"Underground C02 storage, in the correct place," he
said, "Should be a safe option to help us cope with
emissions until we can develop cleaner energy sources."
Although currently no full-scale power plant operates with
a complete carbon capture and storage system, the technology
for it is already commercially available and fairly well
developed.
An example of carbon sequestration at an existing US coal
plant can be found in Texas, where utility company Luminant
is using a technology that captures 90 percent of the carbon
dioxide emitted by a power plant and mixes it with sodium
hydroxide to produce a product we are all familiar with:
baking soda.
Produced at a high grade, the baking soda can either be
recycled for industrial applications or even used for baking.
Luminant installed a pilot version of the technology in
2006, and Skyonics, the start-up company that created the
technology, is now designing a system that it hopes to install
on a large 500-megawatt power plant in 2009.
Cambridge-based GreenFuel Technologies, partnering with
IGV, a private industrial research institute based in Germany,
is another company with an innovative use for carbon emissions:
recycling C02 with algae (one of the world’s fastest-growing
plants) and then converting it into clean, renewable biofuel
or feed.
According to its website, GreenFuel has successfully piloted
its systems at gas, coal, and oil burning facilities, and
is in “active negotiations” with potential partners
to deploy their first commercial installation.
These companies provide remarkable solutions to decrease
the environmental damage caused by C02 emissions. However,
not available yet in any large-scale commercial enterprise,
they do not have the reach needed to make a lasting impact.
If given the permit, one company could make full-production,
clean power plants a reality. Duke Energy is currently awaiting
the "go-ahead" to build a $2 billion, 630-megawatt
coal plant in the United States. If the permit is granted,
the ensuing plant would be large enough to power 200,000
homes a year, making it the world's largest coal-fired power
using a new, cleaner technology, as reported in USA Today.
Dubbed IGCC (which stands for Integrated Gasification Combined
Cycle), this technology turns coal into gas before burning
it, unlike the process in conventional "pulverized" coal-fired
power plants, which crush coal to a powder before burning
it to make electricity.
According to the Environmental Protection Agency, plants
using ICGG technology emit about 65% less mercury and 75%
less sulfur dioxide than conventional plants.
Importantly, Duke Energy's IGCC process also uses Carbon
Sequestration.
Currently, just two coal power plants running on IGCC technology
exist in the United States. Both plants are small and have
been operating for 10 years. Their supporters claim that
they are reliable and can easily become full-scale plants
in their own right.
Richard Payonk, plant manager of a coal gasification plant located in Wabash,
Indiana, stated in USA Today that critics of the technology (who claim is it
is too costly and unreliable) are using old data about its reliability to support
their claims.
Despite the need, for cleaner coal production (since we
are, for now, still burning it), permits for 8 new, clean
coal plants in the United Sates have been cancelled, rejected
or delayed this year.
Why?
Rising construction costs, regulatory issues and environmental
opposition are all factors, reports USA Today.
Next week: The Clean Coal
Debate
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