Missions

The proposed work will consist in developing thermochemical processes applied to solar energy storage at high temperatures using reversible cycles: AB(s,l) + Heat ⇔ A(s,l) + B(g). The main advantages of this type of storage are the high heat storage capacity, the possible long-term storage at ambient temperature in the form of stable solids, etc.

The study will first focus on the selection and comparison of the most promising thermochemical reactive systems. A bibliographic review will be proposed. Then, the study will aim to characterize the chemical reactions and materials at high temperature (thermodynamics, kinetics of storage reactions, …). Experiments using solar furnaces and conventional heating systems will be carried out. The objective will also be to synthesize new materials involving oxides and to study their thermal stability over successive thermochemical cycles. Composite materials will be synthesized via wet (coprecipitation, sol-gel) or solid-state methods for the complete characterization of reactions with thermodynamic and experimental studies (materials reactivity and development of kinetic models for solid-gas reactions). The prepared materials will be characterized with different characterization techniques (XRD, BET, SEM/EDX, TGA/DSC…).

In addition, the selected thermochemical system will be tested in a new solar reactor to be developed. This reactor will be studied experimentally to evaluate its performance (chemical yields, products composition). The obtained products will be analyzed by different materials characterization techniques to determine their composition and morphology. Experimental campaigns will be carried out to determine reactor performance.

In paralell, the solar reactor will be modelled by CFD (Computational Fluid Dynamics, Ansys Fluent) involving heat/mass transfer coupled with chemical reaction. The CFD model will be used to determine the temperature and velocity profiles.
Finally, the integration of these energy storage systems in solar processes at large-scale (solar towers) will be examined through a chemical engineering approach (flowsheet design, heat/mass balances). Techno-economic analysis may also be considered.

Activités

Both experimental and modelling activities will be developed:
- Bibliographic review on thermochemical storage, selection of promising systems;
- Chemical synthesis and physico-chemical characterization of materials,
- Study of thermochemical properties (kinetics, cycling stability, etc…),
- Experimental studies of the solar reactor at the focus of a solar concentrator at Odeillo,
- Determination of performances, mass and energy balances, and products characterization,
- Process engineering: modelling, design, integration, and global analysis of the large-scale process,
- Data treatment, exploitation and detailed analysis of results, reporting/articles writing.

Compétences

The candidate (M/F) (Engineer or PhD doctor) must have a strong background in several of the following fields:
- Solid chemistry (crystallography, physical chemistry),
- Materials science (synthesis and physico-chemical characterization),
- Chemical process and energy engineering (thermochemistry, kinetics, mass/energy balances, heat and mass transfer, CFD modelling, chemical reactors).
The candidate will present results in English (oral presentations, scientific publications and reports). A good practice of scientific English (writing/oral skills) is required.

Contexte de travail

The position is based at the PROMES Odeillo laboratory (CNRS 1 MW solar furnace) located in the Pyrénées Orientales at an altitude of 1600 m, 100 km from Perpignan, 20 km from Spain and 40 km from Andorra. Promes is a research unit of CNRS (UPR 8521) belonging to INSIS institute. One of the PROMES missions is to develop researches with solar concentrating facilities of CNRS at Font-Romeu (solar furnaces in particular) and at Targasonne (Themis solar tower). The work will be carried out in the Solar Fuels team at Odeillo which develops researches on the production of new energy carriers and materials using thermochemical processes.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.