Development of a new reversible machine for heat-electricity conversion by upgrading low-value energy

The International Energy Agency's Net Zero Emission (NZE) strategy targets an increasing share of heat produced from electricity (i.e. by direct heating or via heat pump systems) , which must be around 15 to 40% by 2030 and around 65% in 2050 to meet industrial heat demands at low (< 150°C) and medium temperatures (150°C-400°C). Therefore, the development and massive deployment of efficient heat pump systems are already encouraged to achieve the energy transition of industries towards decarbonization of their heat supply, in particular below 150°C for applications in industries such as as chemicals, paper and agri-food. However, the expected massive electrification of different sectors of activity around 2035 (and in the decades to come) could lead, according to certain authors, to a crisis in electricity supply, particularly to meet the strong energy demand of giga-factories dedicated to the energy transition for local production of batteries and photovoltaic panels.
For these reasons, the HERCULE project aims to develop an innovative thermodynamic cycle capable of responding to the following challenges:
• Societal issues: recovery of waste heat for carbon-free production of electricity or industrial heat according to needs and economic criteria;
• Environmental issues: regulations on greenhouse gases;
• Scientific challenges: flexible conversion systems with reversible operation, compact & efficient machines.

Hybrid ion exchangers for the traetment of radioactive organic liquids: molecular dynamics design assistance

The ECCLOR project (labelled 'Investissement pour le future') focuses on the treatment of radioactive organic effluents by developing porous materials capable of selectively eliminating alpha emitting ions. Research carried out at CEA has led to the design of hybrid materials with variable performance in capturing alpha emitters present in organic liquids. Understanding this performance at the molecular level is essential, but complex.
To address this challenge, this post-doctoral fellowship focuses on the use of classical molecular dynamics to rationalize these performances. The work will be carried out at the Marcoule research center's LILA laboratory, drawing on the expertise of teams specializing in the modeling of solid/liquid systems using classical molecular dynamics.
To support these simulations, experimental data may be provided by laboratories such as the Laboratoire des Procédés Supercritiques et de Décontamination (LPSD) and the Laboratoire de Formulation et Caractérisation des Matériaux minéraux (LFCM). The results obtained will be discussed at progress meetings and will be the subject of scientific publications.
In summary, this post-doctoral contract aims to couple theoretical approaches with experiment. Understanding the interactions within these materials at the molecular scale is essential to provide insights and improve the processes currently under study.

Design of new microfluidic tools for liquid-liquid extraction chemical processes

This 12-month post-doc proposal is part of the PIA MiRAGe: Future Investment Plan “Microfluidic Tools for Accelerated R&D on Recycling Processes”.
The MIRAGE project aims to provide a set of micro and millifluidic tools, platforms and methods to accelerate, intensify and make more flexible R&D on new recycling processes for strategic metals, nuclear or non-nuclear, while minimizing quantities of materials used.
To do this, new microfluidic tools have been designed at CEA ISEC to perform counter-current liquid-liquid extraction operations. These tools make it possible to redefine the orders of magnitude in the importance of the physico-chemical phenomena involved.
The interest of this invention is twofold and will be the core work of this post-doc:
- Carry out extraction operations over very low times and liquid volumes.
- Transpose this invention to larger volumes.
Thus, initially this post-doc work will seek to study in more detail the capabilities of this new microfluidic device, then to transpose this new technique to larger contactors.
The work will be carried out in the ISEC facilities at the CEA, on the Marcoule site in partnership with the CNRS, Universities and the INP of Toulouse.

Behavior of materials in molten salts

Access to clean and affordable Energy is a key challenge in the current context of climate emergency. Several leads have been considered for several years but technological issues remain up to date to make it happen. From concentrated solar plant to 4th generation of nuclear reactor, molten salt is a promising media (both for heat transfer fluid and the fuel itself). Nevertheless, due to the presence of impurities, molten salts are highly corrosive for commonly used materials.
Most of the commercial alloys - either nickel based or iron base - seems to suffer from rapid attack. It is then needed to broaden the scope of the studies by investigating innovative materials. Thus, a screening of materials is planned to select the most interesting ones. After a thorough filtering, a study of the corrosion mechanism will be carried out through analysis at different scales (SEM, DRX, SDL, ICP, etc … )as well via electrochemical techniques and thermodynamic modelisation (HSC and FactSage).
The aim of the post doctoral subject offered at the S2CM (Service of corrosion and Behavior of Materials) consists in the entire study of the behavior, from the sample preparation to the caracterization of corrosion products. This topic is highly experimental and goes deep in the understanding of the corrosion mechanisms. This post doc position is part of a project gathering top - Notch industrial and academics (EDF,Framatome, Orano and the CNRS). Results obtained are subject to be presented to the different partners.

Microfluidic biocatalysis

The overall objective of the project is to propose a new mode of biocatalytic production based on continuous flow and combining macro and micro-fluidics. The aim is to develop a biocatalysis process involving fluidic bioreactors capable of ensuring continuous biotransformation, thanks to immobilized enzymes or whole cell catalysts. This process will be optimized to improve the efficiency of enzymatic reactions on the one hand and to obtain important production capacities on the other hand. Two types of enzymes will be studied, nitrilases and ketoreductases.
First, the candidate will be responsible for the search for robust enzymes for the target reactions and screening on the defined substrates. He or she will be responsible for the development of reaction conditions in isolated enzymes and whole cells and the determination of apparent kinetics. Then, he/she will be in charge of setting up the biocatalysis operating conditions and the immobilization of the biocatalyst in versatile continuous reactors.
This subject is carried out between two departments of the CEA (Direction of Fundamental Research/IBFJ/Genoscope in Evry and Direction of Technological Research/Leti in Grenoble).
The candidate will work in pair with a PhD student on the design of the biocatalytic reactor and the scaling up of the biocatalytic process.

CFD modeling of gas movements in salt cavities

Batteries recycling :Development and understanding of a new deactivation concept of lithium ion domestic batteries

Domestic lithium ion batteries gather all batteries used in electronic devices, mobile phone, and tooling applications. By 2030, the domestic lithium-ion battery market will increase up to 30%. With the new European recycling regulation and the emergency to find greener and safer recycling process, it is today necessary to develop new deactivation process of domestic lithium ion batteries.

The process has to address several lithium ion chemistries, be continuous, safe, controllable and low cost.
To develop this new concept, the first step will be to define the most appropriate chemical systems. Then these chemical systems will be tested in a dedicated experimental laboratory setup using chemistry and electrochemistry, allowing the simulation of real conditions of domestic batteries deactivation.
The third step will be to characterize, understand and validate the electrochemical and physico chemical mechanisms. The last step will be to participate to the validation of the deactivation concept on a real object (a lap top battery) in representative conditions (on the abuse tests plateform of CEA).

Hydrothermal carbonization as a pretreatment of wastes before their thermochemical conversion by gasification

Gasification, a thermochemical transformation generally performed at about 850°C, produces a gas that can be valorised in cogeneration, or for the synthesis of chemical products or fuels. Some bottlenecks are still present mainly for the gasification of biogenic or fossil origin wastes: irregular feeding in the reactor due to the heterogeneity in form and composition; formation of inorganic gaseous pollutants (HCl, KCl, NaCl, H2S) or organic ones (tars), which are harmful for the process and/or decrease its efficiency, and must be removed before the final application.
The objective of the post-doctoral work will be to test and optimize a pre-treatment step of the resource based on hydrothermal carbonisation (HTC). This transformation is performed at 180-250°C, in a wet and pressurised environment (2-10 MPa). The principal product is a carbonaceous solid residue (hydrochar), that can be valorised by gasification. HTC aims to limit the release of inorganic and organic pollutants in gasification, and to homogenise and improve the physical properties of the resource.
The proposed approach will consist in: experimentations in batch reactors on pre-selected resources and model materials, together with quantification and analyses of products; analysis of results aiming at elucidating the links between the resource and the properties of the hydrochar, as a function of operating conditions; an evaluation of mass and energy balances for the HTC-gasification process.

Modelling and evaluation of the future e-CO2 refinery

In the context of achieving carbon neutrality by 2050, the CEA has initiated a project in 2021 to assess the relevance of coupling a nuclear power system with a direct atmospheric carbon capture device (DAC) thanks to the use of the system's waste heat.

As a member of a team of about twenty experts(energy system evaluation, techno-economic engineering, energy system modeling, optimization and computer programming), you will participate in a research project on the modeling and evaluation of a CO2 refinery dedicated to the production of Jet Fuel fed by a nuclear reactor and coupled with an atmospheric CO2 capture process.