Geotimes - March 2003 - Demonstrating Carbon Sequestration

Geotimes

Feature
Demonstrating Carbon Sequestration
Geotimes staff

Introduction
A salty burial
Oil fields: giving and receiving
Value added in coal seams
Making rocks

The National Energy Technology Laboratory

Estimates are that human activity emits 7 billion tons of carbon dioxide a year (see the feature on page 16 in this issue). One proposed method for reducing how much of the greenhouse gas ends up in the atmosphere is to store the carbon dioxide underground. Natural reservoirs of the gas exist, suggesting that geologic carbon sequestration is feasible.

For the past few years, two projects have, combined, been burying 2 million metric tons per year of man-made carbon dioxide instead of sending it into the atmosphere. And researchers in several countries are investigating other options for geologic storage of the greenhouse gas. One of the main goals of these studies is to verify that the gas can in fact remain buried for at least hundreds of years.

“Not only is geologic [sequestration] showing the potential to account for most of the storage,but also, we already have the experience from the oil and gas industry in dealing with geologic formations and wells,” says Scott Klara, product manager for the carbon sequestration program in the U.S. Department of Energy’s National Energy Technology Laboratory. “Geologic will be the first line of defense in sequestration.”

That experience from the petroleum industry is a key tool for monitoring the carbon dioxide after it’s injected into the ground. Seismic surveys, for example, are the means for monitoring sequestration beneath Statoil’s Sleipner natural gas field in the North Sea and EnCana’s Weyburn oil field in Saskatchewan, Canada, the largest projects actively sequestering carbon dioxide in geologic formations today.

One of the biggest challenges for the long term, Klara says, will be finding ways to verify that any buried carbon dioxide is staying put — that is, monitoring for leaks. If large amounts of the greenhouse gas are buried in geologic formations, enough small leaks over time could undo the advantages of sequestration, he says. “Catastrophic levels are going to be easy to find and really are improbable,” Klara says. The small leaks and seepage that can happen through microfractures present the largest monitoring challenge, he adds.

Public perception is also a factor. In Texas, a team with the Bureau of Economic Geology will inject 3,000 tons of carbon dioxide just below an abandoned oil field this summer. As part of their planning, says Susan Hovorka, one of the researchers on the project, they have been talking with nearby residents. “We’re working with local people to make sure they’re comfortable with it,” she says. Hovorka is confident in the geologic understanding her team has of the injection site. Geologists, she says, must make that confidence more robust and communicate it. “We have to show that the geologic understanding of the subsurface is accurate enough. We have an intuition that it’s accurate enough. We have to demonstrate it. … Mostly we have to bring out our understanding to the people.”

Kristina Bartlett

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A salty burial

This summer, a caravan of trucks will travel from the BP oil refinery in Texas City, Texas, to an abandoned oil field east of Houston. The trucks will deliver a commodity that is both valuable and troublesome: carbon dioxide. A team of scientists will inject the carbon dioxide 5,000 feet deep into the Frio Formation, a saline aquifer that sits above the depleted oil reservoir. Then they will watch what happens, using seismic tools and tracers fielded by the Lawrence Berkeley and Oak Ridge national laboratories.

An illustration of how carbon dioxide is buried in a saline aquifer beneath the Sleipner West natural gas field in the North Sea. Photo courtesy of Statoil.

One of the former oil field’s wells will be the doorway for the carbon dioxide, which will have been compressed to a liquid. The team will measure how the already dynamic brine system changes after the carbon dioxide displaces the brine from the rock pores. “We want to observe the CO ₂ plume as it moves from one well to another,” says Susan Hovorka, a geologist with the Texas Bureau of Economic Geology, which is leading this pilot project. “We’re going to perturb a dynamic system. We have to demonstrate rigorously that we won’t perturb it out of its normal fluctuation.” Most likely it will take a few days for the carbon dioxide to spread 100 feet from one well and appear in the monitoring well. Within a few months, it should spread over a few hundred feet away from the injection well. The carbon dioxide should stay put for thousands of years, Hovorka says.

The measurements they make for this small-scale injection experiment will help them to constrain computer models that extrapolate what will happen to much larger volumes of injected carbon dioxide over longer time periods. At the Frio Formation, a layer of shale above the aquifer will most likely contain the carbon dioxide over thousands of years, Hovorka says.

The Frio Formation is similar to the many large salt aquifers that stretch along the Gulf Coast and sit near the plants and refineries in Texas and Louisiana that produce carbon dioxide and emit it into the atmosphere. In fact, her research group estimates that most of the United States is underlain by such aquifers over large areas. The ubiquity of the aquifers means most power plants could store their carbon dioxide in a saline aquifer without building a long pipeline, Hovorka says. Pipelines, along with the cost of capturing and preparing the carbon, add cost to the process.

“The brine formations are available over large geographic areas and large volumes,” she says. “Disposal sites are easy. They’re widely available.” She estimates that the Frio Formation alone could hold between 200 and 350 billion metric tons of carbon dioxide.

Their pilot project is a smaller, land-based version of a large-scale sequestration project in Norway, where the oil and gas company Statoil has, since 1996, been injecting carbon dioxide directly from its Sleipner West natural gas production facility to 1,000 meters deep into the Utsira formation, a saline aquifer beneath the North Sea.

“The process of injecting CO₂ into the ground for storage is costly, but saves Statoil and the license partners about U.S. $110,000 per day in Norwegian CO₂-taxes,” says Rannveig S. Stangeland, a spokesperson for Statoil.

Statoil reports that seismic surveys taken before and after injection started show that the injected gas has not leaked out of the aquifer. The project has put 1 million tons of carbon dioxide into the aquifer every year, and estimates are that the formation, which is 250 meters thick, can hold 600 billion tons. SACS (the Saline Aquifer CO₂ Storage program), a coalition started to monitor the injected carbon dioxide, estimates that the aquifer can store as much carbon dioxide as would be produced over 800 years from all of Europe’s fossil fuel power plants.

SACS is a partnership among the European Commission; several companies, including Statoil; research organizations, including the British Geological Survey; North Sea governments; and, through the International Energy Agency in the UK, the United States, Canada and Australia.

The main disadvantage of saline aquifers as carbon dioxide storage sites, say U.S. researchers, is that injecting the gas in them does not produce another commodity. Injecting carbon dioxide into a depleted oil field, for example, produces more oil and extends the life of the field. But so far, injecting into saline aquifers allows storage but does not produce anything to offset the cost. “Pressuring it to the liquid stage, putting it into the pipeline, and transferring it to the storage site — that’s very energy intensive,” says Curt White, a focus area leader of carbon sequestration science at the U.S. Department of Energy’s National Energy Technology Laboratory. It is also expensive. He estimates carbon capture now costs in the low thirties of dollars per 1,000 tons. “That’s way too expensive. We’ve got to get the cost down. We’ve got to make it definitely more economic.”

In the United States, in the absence of European-style carbon taxes or sequestration trading credits, the energy required to prepare carbon dioxide for storage from a power plant will come from that power plant. Any additional cost for electricity generation will most likely go to the electricity consumer.

Kristina Bartlett

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Oil fields: giving and receiving

The Great Plains Synfuels plant in Beulah, N.D., has been creating natural gas from coal since 1984. The process of converting coal to natural gas releases carbon dioxide, and until 1999 the plant released the greenhouse gas into the atmosphere. “We didn’t have anywhere else to put it,” says Floyd Robb, a spokesperson for Dakota Gasification Co., which runs the plant.

Now, the carbon dioxide is a commodity that has created a new revenue source for Dakota Gasification. For the last 25 years, oil companies have used compressed carbon dioxide to extract additional oil from reservoirs that were considered depleted. They usually tap natural underground accumulations of carbon dioxide, such as the Bravo Dome in New Mexico and McElmo Dome in Colorado. “Because you can use carbon dioxide for oil recovery, it’s a natural process for people to start saying, ‘What if we use man-made CO₂?’” says Scott Klara, product manager for carbon sequestration at the U.S. Department of Energy’s National Energy Technology Laboratory, which researches technologies for carbon sequestration.

Carbon dioxide injected into a depleted oil reservoir dissolves into the remaining oil. In the process, it lowers the viscosity of the oil, making it easier to extract. At the same time, some of the oil remains, sequestering much of the dissolved carbon dioxide with it.

Robb says Dakota Gasification was looking for an oil producer nearby that might want their carbon dioxide. They finally found one in the company PanCanadian Energy Corp., now EnCana Corp., which has been running the Weyburn oil field just over the border in Saskatchewan since 1955.

Dakota Gasification made a large capital investment to add a carbon dioxide compressor to the plant’s process, as well as to build a 200-mile pipeline that would bring the compressed carbon dioxide to Weyburn. Even with this investment, Robb says, selling the carbon dioxide to EnCana is a significant revenue stream. He says the company has added taps along the pipeline in North Dakota, anticipating that oil fields in the state will eventually need the carbon dioxide for secondary oil recovery.

EnCana reports that the injection and recovery project, which started in 2000, will stretch the life of the oil field by 25 years, and that it is the sixth largest recovery project in the world.

Today, about 1 million metric tons of carbon dioxide each year are going from the gasification plant into the Weyburn field, Klara says. The field is sequestering about 40 percent of what is produced at the Synfuels plant, says Malcolm Wilson of the Petroleum Technology Research Centre at the University of Regina in Saskatchewan.

Over the next 10 to 15 years, EnCana will probably inject 18 million tons of carbon dioxide into its 48-year-old Weyburn oil field in Saskatchewan, Wilson adds. “Virtually all of that will ultimately remain in the reservoir,” he says. “Our current view is that CO₂ will remain down there almost indefinitely. Any leakage will be small. The bulk of it, we anticipate, will remain in the reservoir.”

This prediction is based on several factors, Wilson says, including likelihood of earthquakes in the area (not much); likelihood of future mining activities (a possibility because potash and salt lie beneath the oil field); likelihood of small leaks through natural fractures; and, most importantly, likelihood that the gas will escape through the more than 1,000 oil wells dotting the 70-square-mile field. “It’s a big pin cushion,” Wilson says.

DOE and the Petroleum Technology Research Centre are part of a large coalition of Canadian, U.S. and European research organizations, including the International Energy Agency Greenhouse Gas R & D Program in the UK. The coalition is working to monitor the fate of the injected carbon dioxide. “This is a natural system so there are obviously going to be a host of anomalies,” Wilson says. But, he adds, within a reasonable realm of predictability, the group — using seismic surveys taken before and after injection started — is seeing close matches between how the carbon dioxide is moving and how their models suggested it would move. “It’s an old field so we have a huge amount of information on it,” Wilson adds.

Kristina Bartlett

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Value added in coal seams

All around the world, geologists are beginning to look at coal in a new way — not just as a source of energy itself and a host for natural gas, but also as a sink for extra carbon dioxide in the atmosphere. Widespread and generally accessible, deep coal seams could hold as many as 220 billion tons of carbon dioxide. Total world carbon dioxide emissions from fossil fuel flaring and consumption in 2000 reached about 26 billion tons, according to a recent Department of Energy (DOE) study.

Coal seams are an appealing option because of their economic value, says Scott Reeves, executive vice president for Advanced Resources International, an oil and gas consulting firm. The injection of carbon dioxide into coal seams can actually enhance recovery of coalbed methane, a key natural gas resource. “By using coal seams and enhancing methane recovery, it lowers the cost because you’ve got the value-added site benefit of the incremental methane recovery,” Reeves says. “If you try to inject it, for example, into an aquifer, there’s no added benefit; there’s just cost.”

CONSOL Energy has begun drilling in Marshall County, W. Va., as part of a seven-year carbon sequestration project to inject carbon dioxide into coal seams. Photo courtesy of Gary Cairns, CONSOL.

That’s why Reeves is heading up a DOE-sponsored project, called Coal-Seq, to thoroughly evaluate carbon dioxide injection in coal by looking at two companies’ experiences with enhanced coalbed methane recovery. Since 1995, Burlington Resources has been injecting carbon dioxide into wells in the San Juan Basin in New Mexico to recover more methane from the coal beds. And since 1997, BP America has been similarly injecting nitrogen in their wells in the San Juan. Nitrogen, as it turns out, is excellent (though not as good as carbon dioxide) at increasing the recovery of coalbed methane.

“The reason that we’re interested in nitrogen is because flue gas from power plants contains a lot of nitrogen and if you try to sequester the carbon dioxide from the flue gas in power plants, there’s a good likelihood you may have a lot of nitrogen in it as well,” Reeves says. Therefore, Reeves and his colleagues must understand what happens to the injected nitrogen in the coal seam. “Ultimately, the best option might be some mixture between carbon dioxide and nitrogen to get the best economics of both methane recovery as well as the carbon sequestration,” he says.

Although Burlington’s goal in injecting the carbon dioxide has been to increase methane production, it has already sequestered more than 300,000 tons of carbon dioxide. The carbon dioxide, however, is from natural underground reservoirs and not anthropogenic sources, Reeves says. “That source is much less expensive than trying to separate the carbon dioxide from flue gas or some other source.”

Reeves adds that coal seams are a great option for storing carbon dioxide because of coal’s affinity for the gas. The carbon dioxide binds to the coal. “As long as you maintain sufficient pressure on the coal, the carbon dioxide will stay there.” Models indicate that the carbon dioxide does stay in the coal beyond the initial binding process, but they still don’t know how long, he says.

In the northern panhandle of West Virginia, CONSOL Energy has embarked on a $9-million project, also DOE-funded, to inject carbon dioxide into coal seams about 1,260 feet deep. They will drill a series of wells in a square pattern and inject carbon dioxide into a well in the middle of the square. The wells will produce methane from the four sides of the squares for one to two years before they inject carbon dioxide, says Frank Burke, vice president of research and development for CONSOL.

“We need to produce methane from them before we can inject carbon dioxide,” Burke says, to allow room for the gas in the seams. Following the injection will be a five year monitoring period. “It’s a long project but we hope that in the end we’re going to have a good idea of what the potential is for using this type of coal seam approach as a way for managing carbon dioxide emissions.”

Similarly in Poland, the European Union is funding project RECOPOL, which stands for: Reduction of CO2 emissions by means of CO2 storage in coal seams in the Silesian Coal Basin of Poland. RECOPOL is the first experiment of its kind outside of North America. And in North America, in addition to the San Juan and West Virginia projects, the Alberta Resources Council is beginning coal seam experiments in Canada.

Although each study is still at an early stage, Reeves says that coal seams hold great promise for carbon sequestration. The various field experiments will fine-tune researchers’ understanding of coal-seam dynamics to better actualize large-scale projects. Says Reeves: “None of these projects are for sequestering large volumes; they are specifically for the purpose of studying the mechanism of carbon dioxide sequestration in coal seams.”

Lisa M. Pinsker

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Making rocks

Nature has the best track record for sequestering carbon dioxide from the air into the ground, through the process of weathering. Carbon dioxide is slightly acidic and as it reacts with rocks and soil, it converts into other chemical forms. The only problem in putting nature to work on carbon sequestration is that the process takes too long by human standards. In order to help limit the amount of carbon dioxide in the atmosphere, some geologists are looking to speed the weathering process up through industrial means — converting carbon dioxide into carbonate rocks.

“We end up making rocks,” says Klaus Lackner of the Earth Engineering Center at Columbia University. But they have to start with rocks first. To do so, they use magnesium silicates, a class of peridotite rocks that include serpentine and olivine. Exposing magnesium silicate to an aqueous solution of the slightly acidic carbon dioxide forms carbonate and silicate, such as sand. Presto-chango, the carbon dioxide is gone and new carbonates and silicates have replaced the original rock. And the process is exothermic, producing heat. “So its thermodynamics are downhill, it happens spontaneously,” Lackner explains. This is why weathering in nature also occurs over time.

So why aren’t we mass-producing carbonate rocks with our abundance of carbon dioxide? Again, time is the limiting factor. The world has an abundance of magnesium silicate rocks, but reacting those rocks with only carbon dioxide is a slow process. “We are trying to take the process and accelerate it for an industrial setting,” Lackner says.

In order to speed the reaction up, a stronger acid is also needed and, in some cases, additional heat. The Albany Research Center in Oregon, and Ohio State University, are both working on building cost-efficient methods.

Ultimately, achieving large-scale sequestration will mean building power plants at magnesium silicate mines around the world that would convert the olivine and serpentine into carbonates. The newly formed carbonates would then be put back into the mines for permanent disposal.

The Ohio group is fine-tuning their high-pressure, high-temperature, three-phase fluidized bed reactor, an apparatus that uses a mixture of acids to dissolve serpentine in an aqueous solution of carbon dioxide.

“In 30 minutes we can convert about 25 percent of solid magnesium silicate to carbonate at 1,000 [pounds per square inch] pressure and 80 degrees Celsius,” says Ah-Hyung Alissa Park, lead author on a presentation about this technique at the American Institute of Chemical Engineers in November. “At higher temperatures and pressures the conversion rate goes up.”

Still, the science is in its infancy, Lackner says. “It is an example of where we learn more the cleverer and better we will get.”

Christina Reed

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The National Energy Technology Laboratory
Curt M. White, Ken LaSota, Richard J. Jones

Global warming is currently a topic of major interest. Emission of anthropogenic greenhouse gases, such as carbon dioxide from fossil fuel utilization, has been associated with global warming. Multipronged strategies to reduce anthropogenic carbon dioxide emissions include both conservation and increased efficiency. The sequestration of anthropogenic carbon dioxide in underground and oceanic geologic settings is viewed by some as a viable long-term mechanism to reduce atmospheric carbon dioxide levels.

The U.S. Department of Energy's National Energy Technology Laboratory (NETL) has developed a Focus Area where CO2 capture and sequestration in geologic formations and in the deep ocean are being studied. The report, Carbon Sequestration Research and Development, a road mapping document, guides our framing of the overall approach to the work, and is a source to focus individual research projects on specific goals. The report, published in December 1999, was prepared by more than 70 scientists and engineers, using input from more than 200 of their peers, and thus, represents a comprehensive guide to research and development activities and knowledge gaps in the carbon sequestration science arena.

The vision stated in the report is to "possess the scientific understanding of carbon sequestration and develop to the point of deployment those options that ensure environmentally acceptable sequestration to reduce anthropogenic carbon dioxide emissions and/or atmospheric concentrations." The stated goal is to "have the potential to sequester a significant fraction of 1 gigaton of carbon per year in 2025 and 4 gigatons of carbon per year in 2050." Consequently, the goal of the NETL Carbon Sequestration Science Focus Area is to provide the enabling science and engineering to make that vision a reality.

The primary goal of NETL's Focus Area is to develop, and evaluate, to the point of deployment, environmentally acceptable approaches to capture and geologically sequester carbon dioxide. A more recent report, Carbon Sequestration Technology Roadmap was used to further refine and direct the work. The overarching goal of these efforts is to assure safe, long-term sequestration of carbon dioxide.

Carbon sequestration science is a relatively new field. It is remarkably broad-based, encompassing major parts of chemistry, physics, biological and geological sciences, as well as engineering, computational science, and other disciplines. NETL's Carbon Sequestration Science Focus Area divides its efforts into four major tasks: 1) Capture and Separation, 2) Geological Sequestration, 3) Oceanic Sequestration, and 4) Geological Sequestration Modeling. NETL's Carbon Sequestration Science Focus Area does not currently address other research areas, such as, sequestration in terrestrial ecosystems and biological sequestration.

Sequestration science involves the capture and separation of carbon dioxide from large stationary sources such as fossil fuel fired combustion, advanced integrated gasification-combined cycle (IGCC) power plant systems, and oil and natural gas production and refining facilities. NETL is studying both wet and dry capture systems to separate and capture carbon dioxide from both flue and fuel gas streams. Metal bicarbonates, molecular sieves, advanced treated carbons, and new solvents for capture of carbon dioxide are all under investigation as media to capture carbon dioxide from large point sources.

Once separated and captured from flue or fuel gas streams, carbon dioxide can be injected into underground formations such as active and depleted oil and gas reservoirs, economically un-mineable coal seams, or deep saline aquifers (not potable). Long term geologic sequestration results from the interstitial hydrodynamic trapping of the CO2, from in-situ mineral formation between the CO2 and the host environment, or from the adsorption of CO2 into coal. Oceanic sequestration involves dissolution of the carbon dioxide or formation of icelike carbon dioxide clathrate hydrate that can form under the conditions of temperature and pressure that exist in the deep ocean.

At NETL a variety of projects are underway, each intending to acquire the knowledge required to advance one of the major components needed to make geologic sequestration of anthropogenic carbon dioxide a reality. Individual projects are attempting to model and simulate the geological sequestration process in terms of the chemical, physical, and geologic parameters involved in sequestration. Part of the modeling effort, for example, hopes to gain a better understanding of the behavior of carbon dioxide in porous media such as sandstone reservoir rock. In addition, a variety of experimental projects are underway to determine the parameters required to understand the dynamics of sequestration, data that are essential to the sequestration models and simulations being developed and analyzed by NETL.

Investigation of the chemical interactions among carbon dioxide/water/rock is a constant theme throughout the Carbon Sequestration Science Focus Area. It pervades the Geological Sequestration, Oceanic Sequestration, and Geological Sequestration Modeling tasks. Developing a comprehensive understanding of the formation of Ca/Mg carbonates by the reaction of carbon dioxide with minerals, or of carbon dioxide with water to form carbonate anion, bicarbonate anion, and carbonic acid, and their subsequent reactions with minerals or brine, either above or below ground, is vital to much of the work. The kinetics of these reactions must be better defined. The interaction of carbon dioxide and sea water to form hydrates is the major emphasis of the work in the oceanic sequestration task.

A project entitled An Investigation of CO2/Water/Rock Interactions and Chemistry seeks to develop insight into what occurs on a chemical/mineralogical level when large volumes of carbon dioxide are pumped into brine-bearing formations. This project addresses the aqueous chemistry of carbon dioxide with brines and rock. With the U.S. Geological Survey's (USGS) Hydrothermal Laboratory as our partner, NETL is investigating the uncertainties associated with the heterogeneous reactions that may occur with different minerals and strata, as well as the uncertainties associated with the complex ionic equilibria and kinetics of interactions among carbon dioxide, water and rock.

We have assembled a database on brines from all 50 states. Data on more than 65,000 brines, obtained from the USGS, the Texas Bureau of Economic Geology, other state Geological Surveys, and from literature sources, were compiled. NETL intends to make this information available to the public in the near future. The data reside in two commercial software packages: ArcView and Excel. Further, NETL has added the location of existing fossil fuel fired power plants and information on seismic activity to the ArcView database, yielding a more complete picture that will be needed to evaluate and rank the potential of sites for brine field sequestration. These databases will be invaluable resources in guiding future brine field sequestration efforts.

A substantial research effort is directed at experimental and modeling investigations of coal seam sequestration. Specifically, we are studying the environmental factors that affect the ability of coal to adsorb carbon dioxide. The Focus Area has investigated the adsorption isotherms of carbon dioxide on the Argonne premium coals. NETL seeks to more clearly define the effects of a variety of coal seam properties such as temperature, pressure, pH of water associated with the seam, and coal rank on the ability of the coal to adsorb carbon dioxide. A new theory has been developed based upon coal swelling that results in improved fits of both our observed experimental results and results from the literature. This new hypothesis will be incorporated in the reservoir simulators being developed for enhanced coalbed methane (ECBM) production. Another aspect of this project is focused upon estimating the interlaboratory comparability of carbon dioxiode isotherm results obtained on the Argonne premium coals. Two laboratories outside the United States - one at The Netherlands Institute for Applied Geoscience, and the second in Australia at the CSIRO - along with four laboratories in the United States, have agreed to measure the carbon dioxide isotherms on the Argonne coals. This should be a useful exercise in estimating the interlaboratory comparability of such measurements. Additionally, NETL is preparing a comprehensive review article on sequestration of carbon dioxide in coal seams. Before preparation of the review article was initiated, NETL assembled a bibliography of sequestration-related articles. This bibliography was constructed using commercially available bibliographic software, Reference Manager. NETL intends to make the bibliography available to the public in the near future.

NETL is planning to begin construction of a unique facility, a Geological Sequestration Core Flow Laboratory (GSCFL), late in 2002. NETL is designing a flexible state-of-the-art GSCFL where geotechnical properties and chemical reactions can be investigated for a variety of geological formations into which carbon dioxide can be injected. The goal is to be able to simulate the conditions found in all the major categories of potential geological sequestration sites including oil and gas fields, deep unmineable coal-seams, brine formations, and natural gas hydrates. The facility will be designed to accommodate a variety of confining pressures and controlling temperatures for long term experiments while monitoring host rock pore-fluid chemistry. The facility will be designed so that permeability changes can also be monitored continuously during flow. The final design criteria for a facility that can test rock types under a variety of controlled conditions and environments are now being developed. Ultimately, the experimentally derived databases obtained using the GSCFL will provide information on the geotechnical effects and chemical interactions that occur when carbon dioxide is injected into natural rock strata with similar geological and geotechnical properties as those tested at the GSCFL. These results will then be compared with those predicted by modeling experiments, and will ultimately be used to improve the models. Closely linking the laboratory, field, and modeling activities in an iterative relationship will ensure accurate results and maximize progress. The GSCFL will be capable of housing a variety of rock materials, of different sizes and configurations, and will be fully instrumented to record real-time and pre-and post-conditions of the samples during experimentation. When fully developed, the GSCFL will be equipped with a scanning electron microscope, ion chromatograph, XRD, ICP-MS, magnetic resonance imaging, and computer aided tomography, as well as traditional instruments used in petrographic analysis, among others.

Advances in high-speed computing and improved understanding of chemical behavior and fluid flow in porous media permit the use of simulations and modeling as tools for designing, optimizing, analyzing, and better understanding of chemical and physical processes. The Geological Sequestration Modeling task integrates computational science capabilities within the Carbon Sequestration Science Focus Area, building upon the solid foundation of experimental research. It complements and supports the laboratory and field work, and promotes a more thorough understanding of the fundamental science. The major emphasis of the laboratory effort in the Carbon Sequestration Science Focus Area is on geological sequestration and capture technologies. Accordingly, a complementary suite of computational science capabilities is being developed in these areas as well. A holistic approach (consisting of laboratory and modeling and simulation studies conducted in concert) to acquiring the fundamental body of knowledge required to successfully take carbon sequestration to fruition is being undertaken.

In order to accelerate the learning process, NETL has sought and nurtured partnering relationships with other Federal and state government agencies, private industry, and academia. In the areas of Geological Sequestration and Geological Sequestration Modeling, the USGS is our major partner. Working arrangements and collaborative projects have already begun between NETL and other governmental agencies such as the Geological Surveys in Pennsylvania, West Virginia and Illinois, and others. The Focus Area is working closely with both Sandia and Los Alamos National Laboratories, and Strata Productions on a CO2 sequestration experiment in New Mexico at a depleted oil well. Additionally, a number of visiting faculty positions have been garnered with support from the Oak Ridge Institute for Science and Education (ORISE). Industrial partners include Battelle Memorial Institute of Columbus, OH and Sud Chemie of Louisville, KY. Academic partners include the Pennsylvania State University, West Virginia University, University of Texas at Austin, Case Western Reserve University, Carnegie Mellon University, Penn State University, the University of Pennsylvania, Clarkson University, Robert Morris University, University of Akron, Duquesne University, and the University of Pittsburgh, and others. Given the global scope of the CO2 challenge, the broad spectrum of potential technology pathways to meet this challenge, and the stature and degree of recognition the NETL desires in the world of carbon sequestration science in the scientific community, it is critical that a wide range of stakeholders be engaged. As can be seen, the Carbon Sequestration Science Focus Area has developed an extensive set of collaborations with industry, academia and other governmental agencies. These research partners and the staff at NETL are working diligently to realize the mission of DOE's Carbon Sequestration Science Focus Area to "possess the scientific understanding of carbon sequestration and develop to the point of deployment those options that ensure environmentally acceptable sequestration to reduce anthropogenic CO2 emissions and/or atmospheric concentrations."

The authors are with the National Energy Technology Laboratory in Pittsburgh, Penn. Read Carbon Sequestration Research and Development and Carbon Sequestration Technology Roadmap online.

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