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An Organic Geochemical Assessment of CO2-Coal Interactions During Sequestration

February 1, 2004

Three well-characterized coal samples of varying rank were extracted with supercritical CO2 to determine the amount of polycyclic aromatic hydrocarbons (PAHs) that could be mobilized during simulated CO2 injection/sequestration in deep coal beds. The supercritical CO2 extractions were conducted at 40?C and 100 bars, roughly corresponding to a depth of 1 km. The greatest amount of PAHs was extracted from the high-volatile C bituminous coal sample. Extracts from the subbituminous C and anthracite coal samples contained lower concentrations of these compounds. The effectiveness of supercritical CO2 in liberating PAHs from the coal sample was evaluated in a comparison with a parallel series of Soxhlet extractions using 100% dichloromethane. More PAHs were extracted from the lower rank coal samples with dichloromethane than with supercritical CO2. The results from this investigation indicate that, regardless of coal rank, CO2 injection into deep coal beds may mobilize PAHs from the coal matrix. However, more PAHs could be mobilized during CO2 sequestration in a high-volatile C bituminous coal bed than in either of the other two coal ranks studied.

Citation Information

Publication Year 2003
Title An Organic Geochemical Assessment of CO2-Coal Interactions During Sequestration
DOI 10.3133/ofr03453
Authors Jonathan J. Kolak, Robert A. Burruss
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Open-File Report
Series Number 2003-453
Index ID ofr03453
Record Source USGS Publications Warehouse