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Skeptics not totally convinced
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| Pros and cons: Sharon Thomas of St. David presents research at a Northern Cochise County Democrats meeting recently. (Ainslee S. Wittig/photo.) |
Ainslee S. Wittig
Arizona Range News
Some are still skeptical of the promises made in the proposal of a new Integrated Gasification Combined Cycle power plant for Cochise County's small town of Bowie.
A presentation by Sharon Thomas at the Northern Cochise County Democrats meeting in Willcox last month discussed current research on some of the issues mentioned in the proposal for Bowie Power Station.
Thomas, a St. David resident and a teacher, made another presentation at the Cochise County Individual and Property Rights Association (CCIPRA) meeting Saturday in McNeal.
Thomas gave the following characteristics of an IGCC plant:
Sulfur dioxides (SOx), nitrogen oxides (NOx) and particulate emissions are much lower in IGCC plants than from a modern coal plant. Its volatile organic compound (VOC) emissions and mercury emissions are comparable.
IGCC plants emit approximately 20 percent less CO2 emissions than a modern coal plant.
IGCC plants use 20-40 percent less water than a modern coal plant.
IGCC plants operate at higher efficiencies than conventional coal fired power plants, thus requiring less fuel and producing less emissions. Current efficiency is 42 percent with efficiencies as high as 60 percent expected in the very near future using high efficiency turbines and some other process improvements.
Costs for electricity, without CO2 capture, is about 20 percent higher than in a modern coal plant. Electricity costs are 40 percent lower than from a natural gas IGCC plant with natural gas at $6.50 per MMbtu.
CO2 can be captured from an IGCC plant much more easily than from a conventional coal plant at an additional cost increase of 25-30 percent for capture and sequestration, without transportation charges.
IGCC offers the possibility to capture the hydrogen that is part of the syngas stream, in an economic manner.
Issues of concern with the proposed Bowie Power Plant:
Thomas noted several issues with the plant and its technology, starting with carbon dioxide sequestration.
Carbon cannot be sequestered in a fault area (ie. Cochise County)
Energy consumption and costs. The separation of CO2 from the flue gas is energy consuming and expensive; current research aims at the development of alternative separation technologies.
Pipeline to transfer CO2 to its destination is very costly (about $1 million per mile).
Once the CO2 arrives at its destination it must be compressed into a liquid so it can be injected - another costly process.
If any temporary storage is used, depending on the sequestration technology, the carbon dioxide may eventually (after centuries or longer) re-enter the carbon cycle and (partly) return to the atmosphere, which may cause death due to asphyxiation.
And then Thomas said there's the question of whether the plant will really sequester carbon emissions. Mentions of carbon sequestration on the power plant's Web site (www.Bowiepower.com) are: "The University of Arizona's Controlled Environment Agriculture Center is studying how to sequester the captured carbon dioxide in the best way for the Bowie Power Station." And "The Bowie project, unlike traditional coal-fired power plants, will have the capability to capture and sequester CO2 emissions. SWPG is working with the University of Arizona to develop a research greenhouse facility at the site to promote terrestrial sequestration of CO2. SWPG is also working with a commercial grower to develop commercial scale greenhouse production units adjacent to the plant that would also sequester CO2."
Carbon sequestration technology is still expected to be about eight years from commercial introduction (2015). "Ponds with carbon-consuming algae and using CO2 in greenhouses for growing seedlings are still all conceptual," Thomas said.
Thomas noted these plants are not cheap to run: About one-quarter of the energy they produce is consumed for plant operation. All indications suggest that building them on a commercial scale will be expensive and that it will take decades to make a significant contribution to power production.
The efficiency of a CC plant is about 37 percent; the efficiency of an IGCC plant is 45 percent, which appears to be an improvement until one figures in the 25 percent of produced energy, which must be used to keep the plant going. There is another loss of 15-20 percent if the CO2 is compressed and liquified for storage or sequestration.
The actual cost of IGCC-produced electricity is 15-20 percent higher than by a combined cycle (CC) plant.
There are effects on natural resources, according to Thomas:
This facility will not use less water than is currently used on what is now vacant land, "fallow farmland." A combined cycle plant uses 2.2 billion gallons of water annually; an IGCC plant uses about 20 percent less water. Eighty percent of 2.2 billion is still 1.8 billion gallons.
Water contamination in the gasification process is possible, possibly raising the water's pH level.
Is this a "wise use of resources"? It will not lead to better air quality than we have now in Cochise County, as this would bring a second coal-fired power plant to our county.
Emissions are another issue, said Thomas. The gas generated in an IGCC plant is no cleaner than that from a CC plant. The cleaning processes must be attached to the facility, and increase both cost of production and consumer end costs. Removing the CO2 still leaves over 70 toxic chemical compounds in the emissions- including nitrous oxides, sulfur oxides, mercury, and fissionable fuels such as uranium.
Mercury emissions per megawatt-hour from the proposed Mesaba IGCC plant in Minnesota are 15-27 percent higher than either Supercritical or Ultra-Supercritical Pulverized Coal plants (newer types of conventional pulverized coal plant technologies with state of the art pollution control technology Global warming (Carbon Dioxide) emissions from a 500 mw (pulverized) coal-fired plant would be equivalent of about 600,000 cars traveling I-10 every day. For the 600 mw IGCC plant, it would be about 576,000 cars every day," Thomas said.
"According to the Sierra Club, 'Climate scientists say we have a 20-year window to reduce our carbon emissions or climate change will become irreversible,'" Thomas said. "We've got to think outside of the carbon box."
Arizona Range News
Some are still skeptical of the promises made in the proposal of a new Integrated Gasification Combined Cycle power plant for Cochise County's small town of Bowie.
A presentation by Sharon Thomas at the Northern Cochise County Democrats meeting in Willcox last month discussed current research on some of the issues mentioned in the proposal for Bowie Power Station.
Thomas, a St. David resident and a teacher, made another presentation at the Cochise County Individual and Property Rights Association (CCIPRA) meeting Saturday in McNeal.
Thomas gave the following characteristics of an IGCC plant:
Issues of concern with the proposed Bowie Power Plant:
Thomas noted several issues with the plant and its technology, starting with carbon dioxide sequestration.
Once the CO2 arrives at its destination it must be compressed into a liquid so it can be injected - another costly process.
If any temporary storage is used, depending on the sequestration technology, the carbon dioxide may eventually (after centuries or longer) re-enter the carbon cycle and (partly) return to the atmosphere, which may cause death due to asphyxiation.
Thomas noted these plants are not cheap to run: About one-quarter of the energy they produce is consumed for plant operation. All indications suggest that building them on a commercial scale will be expensive and that it will take decades to make a significant contribution to power production.
The efficiency of a CC plant is about 37 percent; the efficiency of an IGCC plant is 45 percent, which appears to be an improvement until one figures in the 25 percent of produced energy, which must be used to keep the plant going. There is another loss of 15-20 percent if the CO2 is compressed and liquified for storage or sequestration.
The actual cost of IGCC-produced electricity is 15-20 percent higher than by a combined cycle (CC) plant.
There are effects on natural resources, according to Thomas:
Emissions are another issue, said Thomas. The gas generated in an IGCC plant is no cleaner than that from a CC plant. The cleaning processes must be attached to the facility, and increase both cost of production and consumer end costs. Removing the CO2 still leaves over 70 toxic chemical compounds in the emissions- including nitrous oxides, sulfur oxides, mercury, and fissionable fuels such as uranium.
Mercury emissions per megawatt-hour from the proposed Mesaba IGCC plant in Minnesota are 15-27 percent higher than either Supercritical or Ultra-Supercritical Pulverized Coal plants (newer types of conventional pulverized coal plant technologies with state of the art pollution control technology Global warming (Carbon Dioxide) emissions from a 500 mw (pulverized) coal-fired plant would be equivalent of about 600,000 cars traveling I-10 every day. For the 600 mw IGCC plant, it would be about 576,000 cars every day," Thomas said.
"According to the Sierra Club, 'Climate scientists say we have a 20-year window to reduce our carbon emissions or climate change will become irreversible,'" Thomas said. "We've got to think outside of the carbon box."
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