1. Scaling in a Geothermal Heat Exchanger at Soultz-Sous-Forêts (Upper Rhine Graben, France): A XRD and SEM-EDS Characterization of Sulfide Precipitates
- Author
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Ghislain Trullenque, Xavier Sengelen, Clio Bosia, Justine Mouchot, Béatrice Ledésert, Olivier Seibel, E. Dalmais, Ronan L. Hébert, Albert Genter, Mariannick Ledésert, Guillaume Ravier, CY Cergy Paris Université (CY), ESGéothermie (GroupeES), Électricité de Strasbourg Géothermie (ES Géothermie), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), UniLaSalle, Bassins - Réservoirs - Ressources - U2R UPJV-UNIL 7511 (B2R), Université de Picardie Jules Verne (UPJV)-UniLaSalle, École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Institut de Chimie du CNRS (INC)
- Subjects
Materials science ,Sulfide ,0211 other engineering and technologies ,Mineralogy ,Scales ,02 engineering and technology ,engineering.material ,Sulfides ,010502 geochemistry & geophysics ,01 natural sciences ,Crystal shapes ,Brining ,Galena ,Heat exchanger ,021108 energy ,Scaling ,Geothermal gradient ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,QE1-996.5 ,Turbulence ,Sulfates ,Geology ,Laminar flow ,As and Sb-bearing galena ,Geothermal site ,chemistry ,[SDU]Sciences of the Universe [physics] ,engineering ,Soultz-Sous-Forêts ,General Earth and Planetary Sciences ,Crystal growth - Abstract
International audience; The Soultz-Sous-Forêts geothermal site (France) operates three deep wells for electricity production. During operation, scales precipitate within the surface installation as (Ba, Sr) sulfate and (Pb, As, Sb) sulfide types. Scales have an impact on lowering energy production and inducing specific waste management issues. Thus scaling needs to be reduced for which a thorough characterization of the scales has to be performed. The geothermal brine is produced at 160 °C and reinjected at 70 °C during normal operation. In the frame of the H2020 MEET project, a small heat exchanger was tested in order to allow higher energy production, by reinjecting the geothermal fluid at 40 °C. Samples of scales were analyzed by XRD and SEM-EDS, highlighting that mostly galena precipitates and shows various crystal shapes. These shapes can be related to the turbulence of the flow and the speed of crystal growth. Where the flow is turbulent (entrance, water box, exit), crystals grow quickly and mainly show dendritic shape. In the tubes, where the flow is laminar, crystals grow more slowly and some of them are characterized by well-developed faces leading to cubes and derived shapes. The major consequence of the temperature decrease is the increased scaling phenomenon.
- Published
- 2021