The durability of materials exposed to corrosive conditions is a major stake as it affects process and plant safety and implies large costs. In real applications and in future “zero emission technologies”, metallic alloys are and will be subjected to oxidizing and water-rich environments at high temperature. Under such conditions, the volatilization of the chromia scale takes place, speeding up the material end of life. While the chromium loss due to volatilization has been estimated many times to assess the material lifetime in past and recent studies, the gas phase evolution and its influence on the volatilization rate are rarely considered although they affect the alloy end of life. To respond to such problem, the DYNAMIC project, which associate 3 academic labs with 2 industries, proposes to evaluate the high temperature oxidation of refractory metallic alloys and the volatilization of their protective oxide layer by an original approach combining high temperature oxidation tests and simulations of the gas phase. Oxidation tests will be carried out between 600 and 1100 °C, under intermediate to high gas velocities (from few tens of cm.s-1 to few m.s-1) and over the complete water vapour content range, i.e. from few ppm to nearly 100 %. Also, characterizations of the samples, before and after oxidation, will be performed. In parallel, the gas phase within the oxidation rigs and the volatilization reaction will be simulated by computational fluid dynamics (CFD). This methodology will be conducted to better understand the influence of dynamic flows on oxidation and volatilization kinetics, and therefore the degradation mechanisms at work in such environments. It shall make it possible the determination of laws capable of predicting lifetime and the evaluation of the effects of geometry to propose solutions to delay the end of life of alloys.

The REPUTER project aims at the development of an efficient, closed-loop and eco-conceived rare earth recycling and separation process from end-of-life rechargeable nickel-metal hydride (Ni-MH) batteries, starting from battery collection down to the formulation of rare earths as pure oxides or metals ready to be used in various industrial applications. Rare earth elements (REE) have become essential for our modern economy, being considered today as the most critical raw materials group with the highest supply risk. Despite this situation, the recovery of REE from Ni-MH batteries is almost non-existent (less than 1% of the REE were recycled in 2011), most of the rare earths present ending up diluted in the slags and their reuse value consequently reduced. This situation is often due to an inefficient collection and sorting process and of various technological difficulties related to REE recovery, extraction, separation and conversion to metals. Therefore, a large effort is needed for overcoming these difficulties and improving the recycling rates, in line with the goals of the EU’s Energy Roadmap 2050. In the same time, recycling activities need to be complemented with new efficient and robust environmentally-friendly separation technologies and with an expertise in the conversion of rare earth oxides into metals or alloys. The objectives of this proposal are to: (i) Reinforce through common objectives the expertise and complementary competences gained in France in hydrometallurgy (spent nuclear fuel reprocessing) and in pyrometallurgy (aluminum, sodium, zirconium industry); (ii) Remove the scientific and technical barriers currently affecting the development of REE recycling, particularly by innovating in terms of dedicated hydrometallurgical and pyrometallurgical process efficiency and compactness; (iii) Bring experimental data and evaluate the possibility to reach a sufficient purity (> 99.5%) of the recycled rare earths at a 10 to 100 gram scale in order to use these purified oxides or metals for industrial applications (catalytic materials, magnets and new batteries); (iv) Evaluate the impact of the recycling process using a life cycle analysis and a technical-economic study, allowing an extrapolation of the process to higher flows and helping the potentially interested industrial companies making an informed decision about the possible commercialization of the process. The work plan is structured into six major tasks (including project coordination). The first step covers the efficient recovery and sorting of REE-rich fractions from end-of-life Ni-MH batteries, via mechanic and thermal operations, followed by acid leaching. The second task will address the optimized extraction and separation of REE from Nickel and other transition elements present in batteries, using hydrometallurgy (liquid-liquid solvent extraction) leading to pure REE in solution. The solvent formulation will be optimized, particularly by designing and studying new selective extractant molecules allowing an efficient intra-REE separation in the presence of transition metals. The conversion of separated light REE (such as La and Ce) into oxides will be carried out in a third task, with the aim of developing ceramic oxide materials with interesting catalytic properties for further valorisation. The forth task is dedicated to the development of pyrometallurgical technologies for the conversion of RE oxides (particularly Nd and Pr) into high purity RE metals. Different types of pyrometallurgical processes mainly based on molten salt electrolysis (alkaline or alkaline-earth chlorides and fluorides) will be studied and optimized in order to propose a robust solution and reach the purity requirements for specific applications (for the NdFeB magnet industry in particular). The last task is dedicated to a life cycle analysis and technical-economic study of the processes.

The behavior of complex multiphase fluids involved in various industrial fields is in large part governed by multi-scale phenomena, coupling interactions at the molecular, meso- and macroscopic scales. Those couplings are still poorly understood and require substantial development in experimental and theoretical knowledge, in order to achieve scientific discoveries that will be transferable to technological applications. Several applications related to energy industries are expected to benefit improvements from molecular and interfacial control of transport phenomena. More generally, any process concerned by the management of complex multiphase fluids and where the mass and heat transfers hindrance causes efficiency loss, will take advantage of extended understanding of multi-scale coupling phenomena. The MUSCOFI project aims at interpreting macroscopic data and predicting macroscopic behaviour by using modelling and experimental tools to elucidate molecular-level phenomena that 1) govern the formation, aggregation, and stability of interfacial and network structures in multi-phase fluids, 2) control their development and effects on macroscopic rheology and transport processes, 3) and finally impact the efficiency of processes in energy technologies. It is a unique opportunity to federate complementary research teams in a new collaborative scheme that will cover the whole scale range, from the molecule to the industrial process. The MUSCOFI project gathers the French partners of an international PIRE project (US NFS program "Partnerships for International Research and Education"), leaded by the City College of New York and that includes 12 research teams from the USA, Germany, Norway, and France. This program includes scientific collaborations, researchers and students exchanges, and symposia organization, on multi-scale investigation of complex fluids of interest to the energy sector. MUSCOFI will thus benefit from synergies at an international level in terms of cooperation, networking and international visibility. The students (2 PhD) and research fellows (2 x 18 months PostDoc) who will be hired during the project will benefit opportunities to spend internships in the partner laboratories abroad, while foreign students will be hosted in the French labs involved. Two systems of particular interest in the field of energy will be investigated within this project: asphaltenes at water/oil interface, and clathrate hydrates in water/oil emulsion. These systems appear in diverse energy applications in oil & gas, heat storage, and environmentally friendly refrigeration. The Tasks of the project are described bellow: 1 The model systems that will be investigated at the different scale levels, as well as the required operating conditions will be validated at the early stage of the project. 2 At the molecular level, the explicit description of the electronic structure will be introduced using an approximate Density Functional based Tight Binding method to retrieve structural, energetic and thermodynamic data. 3 Interactions at the liquid/liquid interfaces in the conditions of solid phase formation will be investigated using microfluidic experiments. 4 The extrapolation of molecular, micro- and meso-scopic results to the macroscopic level will be validated by measuring the influence of the global composition of the systems and the presence of selected additives on flow behaviors, phase change dynamics, and heat and mass transfers. 5 Models will then be developed in an integration and extrapolation approach that will include the local-scale findings to provide macroscopic predictive tools. The project should produce abundent experimental and theoretical new results, promote the development of original methodologies, and offer opportunities for new national and international cooperations. In addition to academic publications, possible patent filling and future industrial partnerships could be valuable outpus of the project.

In the context of hydrometallurgical processes dedicated to the recovery of metals, the leaching step consists of dissolving solid particles (ores, waste to be recycled) in an aqueous phase. With the aim of improving yields, a wiser use of resources and reducing effluents, the BIOMECALIX project aims to study the interest and feasibility of an innovative, competitive and eco-efficient leaching process. This hybrid process combines the advantages of bioleaching (moderate temperature and acidity, in situ production of the oxidizing reagent by microorganisms) and attrition leaching (in situ grinding, abrasion of passivation layers by agitated grinding media). The case of application is chalcopyrite, but the general framework is for leaching processes involving a redox reaction. Such a coupling raises several scientific issues: (i) Does the lifting of the two major kinetic barriers (redox reaction thanks to bacteria and passivation thanks to attrition) make it possible to reach the yields predicted by thermodynamics? (ii) What is the impact of hydrodynamic and mechanical stresses on microorganisms? (iii) What is the limiting step: bacterial growth or activity, gas-liquid transfer (oxygen required for bacterial activity), dissolution reactions, attrition of passivation layers? The proposed methodology combines experimental work in different types of reactors and modeling work. The project gathers a consortium of experts in process engineering, reactor engineering, thermodynamics, modeling, microbiology and hydrometallurgy, at the Chemical Engineering Laboratory (LGC) and at the Geological and Mining Research Bureau (BRGM). It is planned to recruit a doctoral student, a postdoctoral fellow and six trainees during the 42 months of the project. The work program has four technical tasks. The first two tasks concern the adaptation of the uncoupled processes (currently developed by each of the partners) to the conditions of a hybrid reactor. Thus, the attrition leaching will be studied under biocompatible conditions (moderate pH, T between 40 and 55 ° C, oxygen supply) by the LGC, while the BRGM will evaluate the impact of the conditions inherent to the attrition process (high solid/liquid ratio, presence of grinding media, hydrodynamic stresses) on microorganisms. A third task will be to establish the proof of concept of the hybrid process, based on a reasoned selection of operating parameters, and by conducting experimental campaigns in a reactor developed for the project. In parallel, a fourth task will focus on proposing a leaching model integrating thermodynamic equilibria, kinetic laws related to different phenomena, and shear stresses. This model will support the establishment of the balance sheets of the process, and the development of a simulation tool of the hybrid process. This tool will be used for a techno-economic assessment and the establishment of a quantitative comparison (energy and environmental) of the hybrid process compared to existing processes for the treatment of chalcopyrite, in aqueous and pyrometallurgical ways.

Membrane processes know for several years a remarkable growth in the treatment of wastewaters because they are able to deal with water quality and flow fluctuations that conventional activated sludge processes can’t process. Their development remains nevertheless hampered by problems of membrane fouling, which have a negative impact both financial (related to clean-up costs) and environmental (related to the energy cost and chemicals used). Previous works to remove this lock focused on the optimization of operating conditions or configurations of membrane modules, but none of these alternatives has proved to be completely satisfying. Face of the disadvantages of these traditional solutions, the development of low-fouling and self-cleaning membranes would be a major paradigm shift. In this context, the LumiMem project addresses the problem of fouling in a very original way, through the development of a self-cleaning bright membrane textile, hollow fiber (HF) TiO2 polymer membranes with optic fibers (OF) equipped with LEDs UVA. This configuration will enable the in-situ irradiation of TiO2 nanoparticles during membrane filtration. The (super-)hydrophilic character of TiO2 would allow improving the flow water and limitation of the fouling while its photocatalytic and/or disinfectant activity by combination with UVA respectively would induce the degradation of organic matter fouling and a reduction in the development of biofilm on the surface of the membrane. The original goals of the LumiMem project state at several levels: -Design and mastering a new technology of membrane photofiltration, involving the new membrane textile material, to get a treated water of high quality while reducing the environmental impact of the operation (energy and emissions). -Use of new techniques (co-extrusion) to develop polymer hollow fiber containing nanoparticles of TiO2. -Understand and model the mechanisms involved during the developement of the new hollow fiber PVDF-TiO2. -Integrate the issue of sustainability of the technology by studying the ageing of the new membrane textile and comparing its environmental impact compared to the conventional ways of cleaning/cleaning. This new approach of development of TiO2-PVDF membranes and their association with optical fibers generates several scientific risks which have been evaluated and taken into account in the project LumiMem. However, the potential of the project states on preliminary work performed in IEM, having established the proof of concept for the "reference" case of flat-sheet membranes PVDF/TiO2 and having shown, for optimum conditions of development and under UV irradiation, the limitation of membrane fouling and their self-cleaning behavior. The ability to generate results in the LumiMem project is also supported by a consortium that includes academic and industrial actors with recognized, multidisciplinary and complementary skills: IEM Montpellier (development and implementation of membranes, photocatalysis, microbiological processes); LGC Toulouse (ageing of the membranes); Polymem Toulouse (the manufacturer of hollow fiber membranes); Brochier Technologies Villeurbanne (the manufacturer of optic fibers, expertise photocatalysis fabrics).