(Source: The Times-Tribune)

By Robert Swift, The Times-Tribune, Scranton, Pa.
May 10--HARRISBURG -- Depleted oil and gas wells, unmineable coal beds and salt caverns in northcentral and western Pennsylvania are likely candidates to store carbon dioxide emissions, a key step in developing clean coal technology, according to a new state report.
The report by the Department of Conservation and Natural Resources provides a fuller picture of how Pennsylvania would develop a carbon sequestration system to curb greenhouse gas emissions, and thus make coal less polluting.
Western Pennsylvania is considered a primary location for storage because 150 years of drilling for oil and natural gas there have yielded a lot of data about deep subsurface rock formations. Records are available for more than 600,000 wells.
By contrast, only 170 natural gas wells have been drilled so far in central and eastern Pennsylvania, so reliable data is scarce.
"CO2 sequestration efforts in this area are unknown and require much effort to properly assess," the study by DCNR's Bureau of Topographic and Geologic Survey said. "To evaluate the potential for geological sequestration in central and eastern Pennsylvania, detailed mapping is required."
The report generally identifies the larger sources of CO2 emissions in Pennsylvania, the industrial byproduct from burning coal that is considered a factor in global climate change. These include power plants emitting more than 100,000 tons of CO2 annually, iron and steel plants, refineries and cement plants. The largest coal-fired plants emitting from 15 million to 22 million tons of CO2 annually are in southwest Pennsylvania.
Pennsylvania is in the earliest stages of developing a system to capture C02 emissions at their source, compress and cool the gas and then transport it via pipelines for storage in underground "sinks" for thousands of years or more.
The study is important because it finds Pennsylvania has the right geology to support storing C02 underground, said Rep. Greg Vitali, D-166, Havertown, sponsor of legislation authorizing the state to "develop, own and operate" a carbon sequestration network.
A more detailed siting study is to follow. This will use remote sensing and corehole drilling to scout subsurface rock formations in eastern Pennsylvania.
Pennsylvania is competing for federal stimulus dollars available for carbon sequestration projects, an avenue supported by President Barack Obama.
Statewide environmental groups are divided on the merits of carbon sequestration. Some activists voice concerns about the hazards of storing CO2 underground.
The next DCNR study due in November will address these concerns by examining potential risks with this technology. It will look at the risk of CO2 or methane gas leakage out of reservoirs through faults, fractures and improperly plugged wells, the impact of earthquakes, contamination of groundwater and ground disturbance due to overpressuring of the reservoir.
These studies are mandated under a state law enacted last year.
ON THE WEB: www.dcnr.state.pa.us "Carbon Sequestration"
Contact the writer: rswift@timesshamrock.com
-----
To see more of The Times-Tribune or to subscribe to the newspaper, go to http://www.thetimes-tribune.com/.
Copyright (c) 2009, The Times-Tribune, Scranton, Pa.
Distributed by McClatchy-Tribune Information Services.
For reprints, email tmsreprints@permissionsgroup.com, call 800-374-7985 or 847-635-6550, send a fax to 847-635-6968, or write to The Permissions Group Inc., 1247 Milwaukee Ave., Suite 303, Glenview, IL 60025, USA.
A service of YellowBrix, Inc.