Carbon Storage In Geological Formations
Video: Curt Oldenburg, who heads Berkeley Labs Geologic Carbon Sequestration Program, focuses in this lecture on the challenges, opportunities, and research needs of this innovative technology. From UCTV and Lawrence Berkeley National Laboratory's 2009 Summer Lecture Series.
Injection of CO2 into geological formations is currently the most practical option for long-term CO2 storage. The oil and gas industry routinely conducts analogous procedures for several purposes, including disposal of acid gas (natural gas contaminated with large amounts of hydrogen sulfide and carbon dioxide) or liquid waste into spent wells, storage of natural gas in geological formations, and injection of CO2 into wells to enhance oil and gas recovery. Large commercial facilities for geological CO2 storage have been operating for several years at two sites in Salah, Algeria and Sleipner, Norway, and a number of similar facilities are under construction. The cost of such storage is significantly less than that of other CO2 storage approaches.
Current and planned facilities for carbon storage in geological formations.
Several types of geological formations in sedimentary basins are suitable for geological CO2 storage. These include depleted oil or gas fields, deep coal seams, and saline formations. The density of injected CO2 increases with depth; it becomes a supercritical fluid at between 800 m and 1000 m, depending on the rate at which the temperature increases with depth. Supercritical CO2 can remain trapped underground in porous rock formations, which hold or have previously held oil, natural gas, coal, or salt water, that are situated below a layer of impermeable, confining shale and clay rock (caprock). In the absence of deteriorating wells, open fractures, or geological faults, these rock formations should retain nearly all of the injected CO2 for millennia.
Global capacity for geological CO2 storage is large but highly uncertain.  Depleted oil and gas reservoirs may store from 180 to 250 Gt C (gigatons of carbon), coal formations may store from 1 to 55 Gt C, and deep saline formations may store from 270 to 2700 Gt C. Potential storage sites are broadly distributed in most of the world’s sedimentary basins, near many of the emission sources. Given that the world’s total cumulative emissions from fossil fuels may amount to roughly 5000 Gt C, geological CO2 storage would be able to handle a significant proportion of those emissions.
Other carbon dioxide storage methods include pumping CO2 into the sea and converting CO2 into mineral carbonates.
 IPCC (2005) IPCC Special Report on Carbon Dioxide Capture and Storage prepared by Working Group III of the Intergovernmental Panel on Climate Change, Metz, B., O. H. Davidson, C. de Coninck, M. Loos, and L. A. Meyer, eds. Cambridge University Press, New York.
This is an excerpt from the book Global Climate Change: Convergence of Disciplines by Dr. Arnold J. Bloom and taken from UCVerse of the University of California.
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