Scientific background: Geothermal energy is one of the renewable energies that will play a major role during the process of energy transition in Germany. The use of this base load energy source, which can produce both heat and electricity, is especially promising in southern Germany. In the Upper Rhine Graben, the geothermal brines are highly saline and rich in non-condensable gases. The usage of these brings about many problems (e.g. scaling, corrosiveness, enrichment of radionuclides) but also opens up opportunities (element & gas extraction). Research and development on both issues requires analysing brine hydrochemistry & isotopy with high accuracy and scaling (isotope-)geochemistry and mineralogy with high spatial-resolution.
Our strength and some analytical challenges
- Measurement of trace element concentrations and isotopic signatures in highly saline fluid matrices with high accuracy.
- Determination of geochemistry, mineralogy or isotopic signatures in individual layers (10-100 µm) of mineral scalings from geothermal power plants to better understand their formation and possible inhibition.
- Development of experimental techniques to systematically investigate adsorption and desorption of metals dissolved in the brines.
- Design of experiments and improvement of analytical techniques to characterize the inhibiting effect of organic and inorganic compounds on (scale) mineral formation
Current research topics and projects
- Selective extraction of Li from geothermal brines using different adsorbents (CATCHING METALS)
- Characterizing the sulfur cycling in a geothermal power plant including the subsurface using S-Isotopic signatures.
- Understanding the formation of mineral scalings based on high spatial resolution geochemical, mineralogical and isotopic characterization
- Inhibition of mineral scalings using phosphonates
- Eiche, E., Slunitschek, K., Patten, C., Kolb, J. 2018. What can we learn from mineral scalings in geothermal power plants? GEOBONN 2018, 2–6 September 2018, Bonn, Germany, www.geobonn2018.de/assets/geobonn_2018_abstracts_12092018.pdf.
- Haas-Nüesch, R., Heberling, F., Schild, D., Rothe, J., Dardenne, K., Jähnichen, S., Eiche, E., Marquardt, C., Metz, V., Schäfer, T. 2018. Mineralogical characterization of scalings formed in geothermal sites in the Upper Rhine Graben before and after the application of sulfate inhibitors. Geothermics 71, 264-273.
- Eiche, E., Göttlicher J., Steiniger, R., Duschek, K., Eggeling, L., Kölbl, T., Neumann, T. 2017. Arsenic and lead speciation in geothermal scalings: implications on formation conditions. Goldschmidt Abstracts.