*EPF214 12/14/2004
Carbon Sequestration Technology Could Help Slow Global Warming
(Capture and storage could cut a third of total CO2 emissions) (990)

By Cheryl Pellerin
Washington File Staff Writer

(This article is the second in a four-part series on carbon sequestration.)

Washington -- The United States is leading an international effort to make the capture and underground storage of carbon dioxide (CO2) emissions commercially competitive and safe in order to control greenhouse gas emissions and slow global warming.

This series of article about voluntary international effort to reduce carbon dioxide emissions from power plants and improve the technology that makes carbon dioxide capture and storage possible.

THE FORUM

The Carbon Sequestration Leadership Forum (CSLF) is a collaboration among the United States, Australia, Brazil, Canada, China, Colombia, the European Commission, France, Germany, India, Japan, Mexico, Norway, the Russian Federation, South Africa and the United Kingdom to develop improved, cost-effective technologies for CO2 capture and long-term storage.

According to Justin R. "Judd" Swift, deputy assistant secretary for international affairs for fossil energy at the Department of Energy (DOE), CSLF members also work to make the technologies broadly available internationally, to help developing countries learn about and apply the technologies, and to identify and address regulatory and policy issues that relate to carbon capture and storage.

Joint projects are already increasing knowledge in areas that include technology, economics, health, safety and the environment, and they demonstrate a wide range of CO2 capture, transport and storage research and activities.

CO2 sequestration is really two technologies -- CO2 capture and storage. In CO2 capture, carbon dioxide is collected from gaseous emissions -- anthropogenic, or human-made -- arising from fossil-fueled power plants. Emissions are captured, the CO2 is stripped out by chemical methods, and the CO2 can be reused.

In CO2 storage, the captured gases are injected into geologic formations like sandstone or limestone saline aquifers and old oil and gas fields and they remain for centuries or longer, but geologists are still investigating what happens to the gas once it is underground.

CO2 sequestration efforts are those that combine carbon capture and storage by injecting anthropogenic CO2 streams underground.

"The CSLF has recognized 10 projects worldwide," Swift says. "Two of these are the International Weyburn Carbon Dioxide Monitoring Project, a collaboration among the United States, Canada, the European Commission and Japan; and the Frio Brine Sequestration Pilot, a joint project between the United States and Australia."

THE WEYBURN PROJECT

The Canadian company EnCana, the largest independent natural gas producer in North America, operates the Weyburn Oilfield in southern Saskatchewan. Oilfield operations began in 1954. The oilfield produces 10 percent of EnCana's total oil and its production is declining.

In 1997, EnCana began developing a CO2 enhanced oil recovery project to extend the life of the Weyburn field by more than 25 years. DOE and the European Commission are among the research sponsors.

Injecting CO2 into the ground in oilfields reduces oil's viscosity, expands its volume and changes its wettability, or stickiness, allowing companies to get more oil out of the ground.

Weyburn combines carbon sequestration and enhanced oil recovery, says S. Julio Friedmann, who heads the Carbon Storage Initiative at the DOE Lawrence Livermore National Laboratory in California. "They get carbon dioxide from the Great Plains Gasification Plant in Beulah, North Dakota. This was driven purely by economics."

The 50-year-old oilfield was suitable for enhanced oil recovery and needed a carbon dioxide supply, he says. The closest power plant was Great Plains and, because its a gasification plant, it costs less to capture CO2 there than at fossil-fueled plants because of the temperature and pressure at which gasification takes place. This allowed EnCana to build a 325-kilometer pipeline and ship the CO2 from North Dakota to southern Canada.

The project, expected to extract another 120 million barrels of oil from Weyburn, is evaluating the large-scale demonstration of CO2-enhanced oil recovery and developing novel monitoring and tracking techniques to understand CO2 movement in the reservoir.

THE FRIO BRINE EXPERIMENT

The Frio Brine Pilot Experiment is a joint project between the United States and Australia, Judd Swift says. "Its purpose is to ensure safe storage in a saline reservoir. We consider it a key U.S. project for CO2 injection. It began in October 2004 and is expected to continue through March 2005."

Saline reservoirs, also called saline aquifers, show particular promise worldwide for carbon sequestration, he adds.

Geologically speaking, aquifers are formations of sandstone, limestone and other porous rock deep in the earth. Such rock has many pores and the pores contain salty water, also called brine. The rock is permeable, which means water can be taken out and CO2 and other gases can be injected.

Frio Brine researchers drilled a well in 2004 and injected about 1,727 metric tons of CO2 1,500 meters underground at the South Liberty oil field near Dayton, Texas. They plan to demonstrate that injecting CO2 into a brine aquifer is safe for people and the environment, use different monitoring technologies to determine the CO2 distribution underground, and gain experience developing large-scale CO2 injection experiments.

"The Frio Brine Pilot is the first true field experimental facility," Julio Friedmann says. "It's funded largely through DOE but also through corporate sponsors. It's a small project but it's entirely scientific. The only goal is new knowledge and that makes it unique among carbon sequestration efforts globally."

The Australian Cooperative Research Centre for Greenhouse Gas Technologies, known as the CO2CRC, participated in the project.

"The Frio formation is an enormous aquifer on the Texas Gulf coast," Friedmann says. "They wanted to demonstrate that they could store CO2 in that aquifer and, based on what they learned, demonstrate the potential for a large number of carbon storage projects along the Texas Gulf coast."

Part 1 of this series is available at http://usinfo.state.gov/xarchives/display.html?p=washfile-english&y=2004&m=December&x=20041213122136lcnirellep0.6637842&t=gi/gi-latest.html

Information about the CSLF is available at http://www.cslforum.org/

(The Washington File is a product of the Bureau of International Information Programs, U.S. Department of State. Web site: http://usinfo.state.gov)

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