CO2 Capture And Storage Tests Move Forward
Carbon Dioxide Capture and Storage Tests Move Forward
After 10 years of research into the technology and processes for capturing and storing underground the greenhouse gas carbon dioxide (CO2), the Department of Energy (DOE), working with the Environmental Protection Agency (EPA), is moving ahead with the first large-scale U.S. demonstration projects.
Three projects in the United States and Canada will conduct large-volume tests for storing 1 million or more tons of CO2 in deep saline aquifers -- porous rock formations deep in the earth whose pores contain salty water and can be filled with CO2.
On October 11, DOE announced that it plans to invest $197 million over 10 years, subject to approval from Congress, and its project partners will contribute $121 million, according to an October 9 announcement. On October 9, EPA announced plans to develop regulations for geologic CO2 storage, a process that is not yet regulated in the United States. (See related article.)
"EPA is looking to us for our research and development experience, and we're looking to them for their regulatory experience," Robert Kane, technical adviser for carbon management in the DOE Office of Fossil Energy, told USINFO. "When one is based on the other, that makes an awful lot of sense."
Twenty-seven states and the Canadian provinces of Alberta, Saskatchewan and Manitoba will participate in the projects. They will demonstrate the entire CO2 injection process at large volumes to determine the capacity of different geologic settings to permanently store CO2.
"We believe the time is right to begin creating the regulatory framework for commercial-scale carbon sequestration technology," Jason Burnett, EPA associate deputy administrator, told USINFO.
"Currently, about 35 million tons of CO2 are sequestered in the United States," Burnett added, "primarily for enhanced oil recovery. We expect that to increase, by some estimates, by 400-fold by 2100."
Carbon dioxide is one of the greenhouse gases whose presence in excess in the atmosphere is warming the planet and driving global climate change. Many efforts are under way worldwide to reduce greenhouse gas emissions, but one whose use is growing is called carbon (dioxide) capture and storage, or carbon (dioxide) sequestration.
In CO2 capture, carbon dioxide is collected from gaseous emissions that arise from fossil-fueled power plants, refineries, fertilizer production plants and other industrial facilities.
In CO2 storage, captured carbon dioxide, among other methods, can be injected into geologic formations like sandstone or limestone saline aquifers, old oil and gas fields, and coal beds that cannot be mined. The end result is a reduction in the total amount of excess CO2 in the atmosphere.
CO2 will stay underground for geologic timescales -- centuries or longer -- but geologists still are investigating what happens to the gas once it is underground.
In the United States and around the world, engineers have been capturing CO2 from industrial flue streams for about 70 years and injecting it underground for about 30 years to enhance oil recovery.
Injecting CO2 into the ground in an oil field reduces the oil's viscosity, expands its volume and changes its "wettability," or stickiness -- all of which allow drillers to get more oil out of the ground.
But CO2 sequestration efforts -- those that combine carbon dioxide capture and storage by injecting anthropogenic (people-generated) CO2 streams underground -- have been taking place only since about 1997.
SCALING UP SEQUESTRATION
Commercial-scale CO2 capture and storage projects have been under way around the world since 1996 -- at the Sleipner West natural gas field in the North Sea (1996); the Weyburn CO2 Flood Project in southern Saskatchewan, Canada (1997); and the In Salah gas field in the Algerian desert (2004).
The United States has learned from these international operations, Kane said. "We've contributed small amounts of money," he added, "so we could participate in [CO2] monitoring at Sleipner, Weyburn and In Salah, and we've learned by doing."
DOE has run small-scale CO2 sequestration research and development projects since 1997, but the three projects announced October 9 are the first large-scale U.S. field tests.
All are part of the Regional Carbon Sequestration Partnership, which is working to determine the best technologies, regulations and infrastructure needs for CO2 capture and storage in different regions of the United States and Canada. The projects are:
• The Plains CO2 Reduction Partnership will conduct geologic CO2 storage projects in the Alberta and Williston basins. Partners are North Dakota, South Dakota, Minnesota, Montana, Wyoming, Nebraska, Iowa, Missouri and Wisconsin, and the Canadian provinces of Alberta, Saskatchewan and Manitoba.
• The Southeast Regional Carbon Sequestration Partnership will demonstrate CO2 storage in the lower Tuscaloosa Formation Massive Sand Unit, which stretches from Texas to Florida. Partners are Georgia, Florida, South Carolina, North Carolina, Virginia, Tennessee, Alabama, Mississippi, Arkansas, Louisiana and southeast Texas.
• The Southwest Regional Partnership for Carbon Sequestration will inject several million tons of CO2 into the Jurassic-age Entrada Sandstone Formation in the southwestern United States. Partners are New Mexico, Oklahoma, Kansas, Colorado and Utah, and portions of Texas, Wyoming, and Arizona.
EPA is working with DOE to evaluate the potential impacts of CO2 capture and storage on health, safety and the environment. EPA plans to issue its regulations in summer 2008, after reviewing comments from other federal agencies, industry and the public.