John J Burton
Aug. 18, 2008
Aug.20,2009
Feb,27,2010
CCS (Carbon Capture and Storage)
CCS is a technology that will enable us to continue using coal to generate
electricity while emitting only about 15% as much carbon dioxide as now
emitted by coal-fired power plants. I believe that those involved in efforts
to reduce our carbon dioxide emissions have erred badly in not giving a
high priority to proceeding as fast as possible to get CCS demonstration
plants in operation to serve as models for all future power plants.
Meanwhile China and India are busy building coal-fired power plants and U.
S utilities have many in the planning stage
. In 2003 President Bush announced a program called FutureGen. The
government and a group of utilities would build a demonstration power
plant using a new combustion technology called IGCC and it would capture
and store underground the carbon dioxide normally emitted to the
atmosphere. In Jan.,2008 the DOE and private utilities announced plans
for a CCS utility in Illinois but this was canceled when it appeared the ost
would be higher than had been projected. In Dec, 2009 the DOE
announced plans for several commercial utilities using CCS to be built by
private utilities with DOE sharing the cost.
In WV, American Electric Power began to operate a CCS operat ion with a
portion of the emission from a power plant. This will sequester and bury
100,000 tons annually of CO2 into a layer of sandstone 7,000 feet
underground. This project uses chilled ammonia as a solvent.It went into
operation in 2009.
I believe the predicted catastrophic effects of global warming warrant our
not waiting for 2016 demonstrations of CCS . Instead we should mandate
that it be included in any new coal-fired power plants. There would be
added construction and operating costs that would have to be borne by
the government and/or consumers.
The CCS Process
The application of CCS to power plants is as follows:
The stack gas is passed through a scrubber containing a solvent to absorb
its CO2; this is the sequestering or carbon capturing step. In the next
step, the CO2 is extracted from this solvent, compressed, cooled, and
injected in the form of a supercooled liquid deep underground into a
geological formation or underneath an ocean bottom.
This sequestering step is a proven technology that has been in commercial
use for years. CO2 sequestration can be applied to any fossil fuel power
plants, but since use of coal generates much more CO2 per unit of
electricity, its application to coal-fired plants offers the biggest reduction in
CO2 emissions. CCS could also be applied to any large stationary source of
CO2 such as cement plants. To date, the policies advocated by those
concerned about global warming have been chiefly along two lines. . We
should use energy more efficiently and obtain more of our energy from
renewable sources. But, even with optimistic estimates , these alone will
not achieve near the 60-80% reduction in emissions the climate experts
say we need by 2050. CCS offers a another means of a substantial
reduction of CO2 emissions. The prestigious IPCCC (Intergovernmental
Panel on Climate Change) says use of CCS can achieve 30-40% of the 60-
80% reduction we need to reach by 2050.. An MIT (Massachusetts
Institute of Technology) 2007 study recommended that the U.S.
government should promptly assist in the construction of 3-5 large power
plants to demonstrate CCS
CCS can provide another means to cut emissions although at this time we
do not know how its cost would compare to the cost of renewables. There
have been wide variations in the estimates of the added cost of including
CCS to power plants and it seems a reliable figure will not be established
until demonstration plants are in operation. . And research is going on at a
number of institutions for better technologies to lower the cost of CCS.
The common practice has been to use ethanolamine to absorb the CO2
but there is little doubt that a better method will be found such as use of a
membrane for this separation.
Some environmentalists have questioned the the safety of storing large
amounts of C02 underground or under the oceans. But safety as well as
capacity at a number of potential sites has been studied for several years
The IPCC in a 2005 special report on CCS said: “In properly selected and
managed geological storage sites, it is very likely that leakage will not
exceed 1% in 100 years and likely that it will not exceed 0 1% in 1,000
years” Most of the storage would be in deep saline formations where cap
rock prevents CO2 from escaping to the surface. We will need government
regulations to ensure that safe storage sites are selected, and that
effective monitoring of leakage is carried out.
For many years CO2, by a process known as EOR, has been injected into
depleted oil fields, now amounting to 33 million tons per year.. Monitoring
has found no leakage. EOR has become a common practice in western
United States and Canada; in one case CO2 from a U.S. power plan is
being sent by pipeline to Canada and injected there in a depleted oil field.
Recent new EOR inject ions are in Africa and in the North Sea.
Studies indicate that the U.S. has geological formations that could safely
store CO2 from our power plants for a long time.. The DOE has estimated
that the U.S. storage capacity amounts to what would be needed for 200
years of burning fossil fuels at the present rates. The DOE is still funding
studies in a number of areas to determine the safe capacity for this
storage at various sites. The IPCC in its 2005 report said estimates of
global storage were as much as 1,100billion tons a year of CO2.).
In Norway, since 1996 , Statoil has been separating CO2 from natural gas
and injecting 2 million tons a year offshore into a deep underground
reservoir Most power plants today use the standard pulverized coal
technology. CCS can be added to these plants as an additional step but
this is very expensive. Many new plants of this type are planned and CCS
could be included in the design and construction of these at a cost much
less than adding it to existing plants. .
The least added cost for CCS would be to include it in any of the new high
technology plants This is because in these plants the CO2 that is
produced is in a mixture with hydrogen, a much lighter gas, so it is easier
to separate it. Another advantage for these plants is that they have no
mercury, nitrogen oxides or sulfur dioxide in the emissions.
One of these new technologies is known as IGCC. It has been in successful
operation for 10 years in a Tampa power plant. As the next step in the
FutureGen project the DOE will this summer select several sites where a
group of power companies will construct plants with IGCC technology. At a
cost of $100 t0 $600 million each, DOE will design and finance the addition
of CCS to these plants. They are expected to start operations in 2016.This
program was first proposed in 2003
t the present time U.S. utilities would like to build many more coal-fired
power plants, mostly using the pulverized coal process. Construction of
some is being delayed by environmental organizations and by state and
local governments. And major banks are now reluctant to finance them in
fear of legislation that would tax CO2 emissions China and India are
rapidly constructing more coal-fired power plants of the common
pulverized coal type. Last year the International Energy Agency reported
that global use of coal was expected to increase 73% by 2030. So it is
very likely that there will be a big increase in CO2 emissions from power
plants years before CCS will be employed to reduce CO2 emissions. And if
the new power plants have not been designed to include the addition of
the CCS operation, it will be very expensive to add it to them.
It is uncertain how much CCS will add to the cost of generating electricity.
and widely differing estimates have appeared in the literature. If CCS is
included in new plants, most estimates are in the range of a 30% to 60%
increase. For IGCC plants, the first operation , expected in 2012, should
provide an answer. And by that time maybe there will be new pulverized
coal plants in operation with CCS to clarify the added cost for these.
The first demonstration of CCS will probably be in at an American Electric
Power coal-fired power plant in West Haven, WV. In 2003 a 9100 ft. hole
was drilled and testing carried out by Battelle Laboratories which
demonstrated its suitability for storing CO2. AEP now plans to sequester
some of the CO2 at its adjacent power plant and inject it here. So by 2012
we may have a small scale demonstration of CCS being added to a
pulverized coal power plant.
IGCC technology produces hydrogen as an intermediate step in generating
electricity, so instead of burning this to produce electricity, it could be used
as a fuel for cars and trucks. In the long term, this could supply hydrogen
as a transport fuel as an alternate to producing hydrogen using solar or
wind power. In 2003 , DOE plans include hydrogen production as wll as
electricity from FutureGen power plants. But current planned projects
omit hydrogen production and DOE has not said why .this has been
omitted.
Notes
We conclude that CO2 capture and sequestration (CCS) is the critical
enabling technology that would reduce CO2 emissions significantly while
also allowing coal to meet the world’s pressing energy needs.”
( From the Executive Summary of the MIT Study of the Future of Coal.)
This (CCS) would be the bridging technology between using fossil fuels
and the new low-carbon technologies.”
(Sir David King and Gabrielle Walker in their book “Hot Topic”)
Global coal use is expected to increase 73% by 2030.
( International Energy Agency Dec 2007)
The CO2 emissions in the US, about 50% are from stationary sources
with CCS potentially applicable to these.
( EPA)
In 2004 a consensus of cost estimates was that addition of CCS to an
IGCC power plant would increase the capital cost by 36 %, the operating
cost by 50% and the fuel cost by 20% so the overall cost per KWH of
producing electricity would rise from 5.0 cents to 6.7 cents.
( A 2004 study at the University of Florida)1
The Sept. 25, 2005 IPCC “Special Report on Carbon Capture and
Storage” includes the following:
The addition of CCS to a new pulverized coal-fired plant would increase
the capital cost by 44-74% and increase the operating cost by 1.8-3.4
cents per KWH
To add CCS to a new IGCC plant would increase the capital cost by 19-
66% and increase the operating cost by 0.9-2.2 cents per kwh .With
current power plant technology, 85-95% of emitted CO2 can be captured,
but this requires an additional 10-20% more energy for the CCS step, so
the net effect is that CCS reduces the CO2 emissions of a power plant by
80-90%. Storage of CO2 in deep, onshore or offshore, geological
formations uses many of the same technologies that have been developed
by the oil and gas industry and have been proven to be economically
feasible under specific conditions for oil and gas fields and saline
formations, but not yet for unmineable coal beds.”
Scenario studies indicate that by 2050 around 20-40% of total global
fossil fuel CO2 emissions could be technically suitable for capture
including 30-60% of electricity generation and 30-40% of industrial CO2
emissions.With appropriate site selection, the local health, safety and
environment risk of geological storage would be comparable to risks of
current activities such as natural gas storage, Enhanced Oil Recovery
(EOR), and deep underground storage of acid gas. “Model calculations for
the capacity to store carbon dioxide in the oceans indicate that the
capacity could be on the order of thousands of gigatons , depending on
the assumed stabilization level in the atmosphere and on environmental
constraints such as ocean ph. “Available evidence suggests that worldwide
it is likely that there is technical potential of at least 2,000 gigatons of
carbon dioxide storage capacity in geological formations. “ 60% of the
global CO2 emissions, now 23.5 Gt, are from stationary sourses and so
could be sequestered and buried.
CCS
