The cost of meeting increased cooling-water demands for CO_2 capture and storage utilizing non-traditional waters from geologic saline formations

摘要

Deep (> ~800 m) saline water-bearing formations in the United States have substantial pore volume that is targeted for storage of carbon dioxide (CO_2) and the associated saline water can be extracted to increase CO_2 storage efficiency, manage pressure build up, and create a new water source that, once treated, can be used for power-plant cooling or other purposes. Extraction, treatment and disposal costs of saline formation water to meet added water demands from CO_2 capture and storage (CCS) are discussed. This underutilized water source may be important in meeting new water demand associated with CCS. For a representative natural gas combined-cycle (NGCC) power plant, simultaneous extraction of brine from the storage formation could provide enough water to meet all CCS-related cooling demands for 177 out of the 185 (96 %) saline formations analyzed in this study. Calculated total cost of water extraction, treatment and disposal is less than 4. 00 US Dollars (USD) m~(-3) for 93 % of the 185 formations considered. In 90 % of 185 formations, treated water costs are less than 10. 00 USD tonne~(-1) of CO_2 injected. On average, this represents approximately 6 % of the total CO_2 capture and injection costs for the NGCC scenario.