THERMOSALT: Characterisation and simulation of thermodynamic and physicochemical properties of natural and industrial brines


Brines are aqueous solutions that are highly enriched in dissolved mineral and salt compounds. They can be natural (geothermal water or water from oil reservoirs) or from industrial processes (mainly seawater desalination plants).

The existence of these brines and their treatment can pose many problems:

  • From an environmental point of view: because, when they are released, they disturb the local fauna and flora due to their chemical composition, which is very rich in minerals and salts (industrial context).
  • From an industrial exploitation point of view: because the extraction of these brines from deep underground is inevitably accompanied by the appearance of minerals in the exploitation facilities, generating maintenance costs and, in some cases, production stoppages or curtailment of operations.

Currently, minerals and other valuable substances are not extracted from these brines, as the cost of production would be higher than their market value. In view of the very strong increase in demand for fresh water and the multiplication of treatment plants, the extraction of these minerals, which has not been profitable until now, could become so in the future. In terms of the geopolitical supply of metals (lithium, copper, magnesium,…) to industrial sectors, control of the chemical behaviour of brines can contribute to the exploitation of certain metal deposits by identifying favourable geological environments.

It is therefore necessary to master the behaviour of this type of brine when it crystallises in order to propose economically and environmentally profitable processes. This (i) to anticipate the major environmental risks associated with their exploitation, and (ii) to extract valuable substances that are economically profitable in order to reduce production costs.

To achieve this objective, scientific tools exist to predict the behaviour of these brines during their crystallisation. These predictions are based on powerful computational tools that require the results to be compared with reality, i.e. with experimental data.

In order to address these issues, the THERMOSALT thesis project proposes to associate two partners with nationally recognized expertise in the fields of crystallization and geosciences.

  • The laboratory of Sciences and Separative Methods (SMS) of the University of Rouen-Normandy, expert in the determination of experimental data related to the crystallization process.
  • The Bureau de Recherches Géologiques et Minières (BRGM), a public industrial and commercial establishment which is the national geological survey and which has been working on the subject of brine recovery for over 20 years. This organisation has the expertise to carry out predictive geoscience calculations.

The objective of the work of the requested thesis is to continue to be able to respond to environmental and industrial and industrial problems. The aim is to meet the new and growing needs of industry for the development of innovative technologies regarding the management and/or the valorisation of brines (whether in the oil or geothermal domain), energy storage (CO2, H2 or other energy vectors) in saline geological aquifers.

To meet this major objective, it is constantly necessary to feed the thermodynamic models (Pitzer theory) with experimental data from the acquisition of specific data on solutions (water activity, osmotic coefficient, speciation in solution, etc.) and on solids (characterisation of salts, solubility, deliquescence threshold, etc.).

The doctoral student recruited will work on chemical systems present in natural or industrial brines, allowing for the recovery of dissolved products, particularly those based on metals (lithium, copper, etc.). The behaviour of the calcium sulphate system may also be a topic of interest, with a particular focus on the hydrated-to-anhydrous phase transition.

To carry out his/her work, the PhD student will be supervised by the teams of the two partners (SMS lab and BRGM). His/her technical objectives will be:

  • To characterise and analyse solid-liquid (precipitation/crystallisation) equilibria. Thermodynamic data will be generated using existing experimental methods or by developing dedicated prototypes. These experiments will be carried out in the SMS laboratory (Rouen).
  • To acquire water isoactivity curves for the most soluble aqueous mixtures and model, by means of dedicated calculation codes and associated databases, the experiments. This part, including the experimental approach and the integration and interpretation of the data, will be carried out at BRGM (Orléans).


Contact for submission of application before 20 May 2022:

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Antoine Burel, Nicolas Couvrat, Séverine Tisse, Yohann Cartigny, Pascal Cardinaël et al. Binary phase diagrams between phenanthrene and two of its impurities: 9,10-dihydroanthracene and carbazole, European Physical Journal - Special Topics, EDP Sciences, 2017, 226 (5), pp.869 - 880.

Nicolas Couvrat, Julien Mahieux, Baptiste Fours, Yohann Cartigny, Eric Schenkel et al. Impact of sodium chloride on the expansion of a liquid-liquid miscibility gap in an API/water system. Case study of Brivaracetam. International Journal of Pharmaceutics, Elsevier, 2016, 515 (1-2), pp.702 – 707

Lina Yuan, Clevers Simon, Nicolas Couvrat, Yohann Cartigny, Valerie Dupray et al. Precise Urea/Water Eutectic Composition by Temperature-Resolved Second Harmonic Generation, Chemical Engineering and Technology, Wiley-VCH Verlag, 2016, 39 (7), pp.1326 – 1332

Clément Brandel, Gabin Gbabode, Yohann Cartigny, Claudette Martin, Géraldine Gouhier et al. Crystal Growth, Structure, and Polymorphic Behavior of an Ionic Liquid: Phthalate Derivative of N-Butyl,Nmethylimidazolium Hexafluorophosphate, Chemistry of Materials, American Chemical Society, 2014, 26, pp.4151-4162.

  1. Schindler, Nicolas Couvrat, Yohann Cartigny, Clément Brandel, Gérard Coquerel. Synthesis and Characterization of sodium dithionate and its dehydrate, Chemical Engineering and Technology, Wiley-VCH Verlag, 2019

Adeline Lach, Laurent André, Arnault Lassin, Mohamed Azaroual, Jean-Paul Serin, and Pierre Cézac. A New Pitzer Parameterization for the Binary NaOH–H2O and Ternary NaOH–NaCl–H2O and NaOH–LiOH–H2O Systems up to NaOH Solid Salt Saturation, from 273.15 to 523.15 K and at Saturated Vapor Pressure. Journal of Solution Chemistry, 2015, 44, pp. 1424-1451.

Adeline Lach, Faïza Boulahya, Laurent André, Arnault Lassin, Mohamed Azaroual, Jean-Paul Serin, and Pierre Cézac. Thermal and volumetric properties of complex aqueous electrolyte solutions using the Pitzer formalism – The PhreeSCALE code. Computers & Geosciences, 2016, 92, pp. 58-69.

Arnault Lassin, Christomir Christov, Laurent André and Mohamed Azaroual. A thermodynamic model of aqueous electrolyte solution behavior and solid-liquid equilibrium in the Li-H-Na-K-Cl-OH-H2O system to very high concentrations (40 molal) and from 0 to 250 °C. American Journal of Science, 2015, 315, pp. 204- 256.