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Title: CO2 Sequestration in Unmineable Coal Seams: Potential Environmental Impacts

Conference ·
OSTI ID:938822

An initial investigation into the potential environmental impacts of CO2 sequestration in unmineable coal seams has been conducted, focusing on changes in the produced water during enhanced coalbed methane (ECBM) production using a CO2 injection process (CO2-ECBM). Two coals have been used in this study, the medium volatile bituminous Upper Freeport coal (APCS 1) of the Argonne Premium Coal Samples series, and an as-mined Pittsburgh #8 coal, which is a high volatile bituminous coal. Coal samples were reacted with either synthetic produced water or field collected produced water and gaseous carbon dioxide at 40 οC and 50 bar to evaluate the potential for mobilizing toxic metals during CO2-ECBM/sequestration. Microscopic and x-ray diffraction analysis of the post-reaction coal samples clearly show evidence of chemical reaction, and chemical analysis of the produced water shows substantial changes in composition. These results suggest that changes to the produced water chemistry and the potential for mobilizing toxic trace elements from coalbeds are important factors to be considered when evaluating deep, unmineable coal seams for CO2 sequestration.

Research Organization:
National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR
Sponsoring Organization:
USDOE - Office of Fossil Energy (FE)
DOE Contract Number:
None cited
OSTI ID:
938822
Report Number(s):
DOE/NETL-IR-2005-215; NETL-TPR-1225
Resource Relation:
Conference: 22nd Annual International Pittsburgh Coal Conference, Pittsburgh, PA, Sept. 12-15, 2005
Country of Publication:
United States
Language:
English