Abstract
Thermal water is increasingly used for heat and electric power production and provides base-load capable renewable and virtually unlimited geothermal energy. Mineralized deep thermal water may, however, induce precipitation along the water circuit of geothermal power plants. Scaling can considerably impact on the plant’s efficiency of energy extraction. Water-rock-interaction may provoke further unfavourable scenarios of decreasing plant efficiency, particularly observed during the reinjection of thermal waters into sandstone formations. In this case, a decrease of permea-bility of the host rock can be caused by (i) mobilization/settling of fine particles within the pore spaces or (ii) temperature and pressure induced formation of mineral precipitates.
In order to get an improved understanding of these efficiency reducing reaction mechanisms dur-ing exploitation and reinjection of thermal waters, we apply hydrochemical modelling, experimental simulations (e.g. flow-through systems), high-resolution imaging (e.g. SEM, XCT scanning) and state-of-the-art geochemical techniques, such as trace element and isotope geochemistry to fluid and solid samples. This multi-technique approach is used to decipher, e.g. (i) kinetics and mech-anisms of nucleation and crystal growth and (ii) the degree of the permeability reduction as a function of temperature, pressure and chemical composition of the thermal waters. Detailed knowledge on reaction mechanisms and pathways is strongly required to significantly enhance the sustainability and economic viability of hydrogeothermal power plants.
In order to get an improved understanding of these efficiency reducing reaction mechanisms dur-ing exploitation and reinjection of thermal waters, we apply hydrochemical modelling, experimental simulations (e.g. flow-through systems), high-resolution imaging (e.g. SEM, XCT scanning) and state-of-the-art geochemical techniques, such as trace element and isotope geochemistry to fluid and solid samples. This multi-technique approach is used to decipher, e.g. (i) kinetics and mech-anisms of nucleation and crystal growth and (ii) the degree of the permeability reduction as a function of temperature, pressure and chemical composition of the thermal waters. Detailed knowledge on reaction mechanisms and pathways is strongly required to significantly enhance the sustainability and economic viability of hydrogeothermal power plants.
Original language | English |
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Title of host publication | Proceedings, German Geothermal Congress DGK 2017 (Munich) |
Publication status | Published - 14 Sept 2017 |
Event | Der Geothermiekongress DGK 2017: German Geothermal Congress - BMW Welt, München, Germany Duration: 12 Sept 2017 → 14 Sept 2017 |
Conference
Conference | Der Geothermiekongress DGK 2017 |
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Country/Territory | Germany |
City | München |
Period | 12/09/17 → 14/09/17 |
Fields of Expertise
- Advanced Materials Science