Water-driven geothermal heat extraction with simultaneous CO2 injection: overview of concepts, benefits and challenges
International audience Geothermal energy production and CCS (Carbon Capture and Storage) represent promising technological solutions to help mitigate climate change and aid the current global energy crisis. In recent years, the number of concepts that propose to combine and mutualize these technolog...
| Main Authors: | , , , |
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| Other Authors: | , |
| Format: | Conference Object |
| Language: | English |
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HAL CCSD
2024
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| Subjects: | |
| Online Access: | https://hal.science/hal-04460122 https://hal.science/hal-04460122/document https://hal.science/hal-04460122/file/EGU24-10031-IEAGHG.pdf |
| Summary: | International audience Geothermal energy production and CCS (Carbon Capture and Storage) represent promising technological solutions to help mitigate climate change and aid the current global energy crisis. In recent years, the number of concepts that propose to combine and mutualize these technologies has risen dramatically. While a number of concepts (notably CPG and CO2-EGS) use supercritical CO2 as the heat vector, another promising route for hybridization is to inject dissolved CO2 in the geothermal brine. This is the focus of our current work. An extensive literature review was carried out of the concepts, complemented by interviews with developers of certain concepts. A few concepts are still theoretical (only described in the literature), but most technological concepts are on the way to pilot/demonstration projects at progressively increasing scale. The main projects and their associated sites are:-CO2-DISSOLVED concept, with potential sites identified in the Paris basin (France);-AAT-G / Cleag concept, with a site in Croatia;-Related projects CarbFix, GECO and SUCCEED, with sites in Hellisheidi (Iceland), Nesjavellir (Iceland), Bochum (Germany), Kızıldere (Turkey), Castelnuovo in Italy (as case study due to permitting issues);-Reinjection of CO2 from geothermal brines at Ngatamariki and Te Huka sites in New Zealand.Despite similarities, the concepts are differentiated by their purpose: i.either to store CO2 from an external industrial emitter (notably for the CO2-Dissolved concept), thus bringing a contribution to CCS, ii.or to reinject CO2 emitted by CO2-rich brine during geothermal exploitation, thus bringing geothermal to near-zero emissions.Because of the CO2 solubility limit in brine, the performance of heat extraction is generally higher than that of CO2 storage. For instance the CO2-DISSOLVED technology is particularly well-suited to small CO2 industrial emitters (ca. <150,000 t CO2/year). Unlike concepts using supercritical CO2, those using dissolved CO2 can be deployed at lower depths (no ... |
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