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Reference : UPR8521-MARBAL-002
Workplace : FONT ROMEU ODEILLO VIA
Date of publication : Thursday, October 10, 2019
Type of Contract : FTC Scientist
Contract Period : 12 months
Expected date of employment : 14 October 2019
Proportion of work : Full time
Remuneration : between 2600 and 2900 €/month
Desired level of education : PhD
Experience required : 1 to 4 years
In the frame of the ANR STELLAR project, we are looking for a post-doctoral student for 12 months (+ 12 months more after) beginning at october 14, 2019.
Energy and climate policies represent top priorities for the next decades, leading to both incentives and stringent regulations to decrease greenhouse gas (GHG) emissions. The main target of STELLAR is to provide a new energetic vector ensuring no GHG and ultra-low pollutant emissions. To answer both global scale and carbon dioxide emissions issues, hydrogen may be seen as a possible candidate to store overproduction from renewables; similarly and mainly due to storage and distribution complexities related to hydrogen, micrometric metal particles could be a better option especially for long-term energy storage
The high energy density inherent to reactive metals, which motivates their use as additives to propellants and energetic materials, or as anodes within batteries, also inspires their use as recyclable solar fuels. Metal particles show a very good energy density, similar to liquid hydrocarbons, enabling, in a transportation context, a much higher autonomy than a pure electric vehicle, even at long-term.
The possibility to use metal powders to store energy from intermittent renewable energy sources will arise naturally in this project. Since metals are not available in pure reduced form in the Earth's crust, they need to be produced from their oxides (ores or discarded metallurgical by-products). Unlike hydrocarbons, the energetic content will be introduced by the reduction process of the material itself. Thus, to keep the well-to-wheel GHG emission levels close to zero, the oxide reduction occurring after combustion of metal particles will be done in a separate process and location using concentrated solar energy. The interest of using concentrating solar energy is double: first, to reach very high temperatures in a few seconds for the reduction of oxide particles in controlled atmosphere and second, and to develop an improved energetic and clean (less GHG emission) process than the current ones (Pidgeon and Hall-Héroult).
The main objective is to provide a virtuous process to regenerate oxides, based on a solar-powered renewable source. The relevant Sol@rmet reactor existing and operational at CNRS-PROMES has allowed to demonstrate the feasibility of the production of metals using concentrated solar energy at 10 mbar using carbon as reducing agent and Ar as carrier gas. It has also allowed to obtain nearly pure magnesium and aluminum powders (respectively up to 98 %wt and 82 %wt) with yields close to 60% at the same pressure. However, the main problems of the carbothermal reduction of the studied oxides - Al2O3 and MgO - are bounded to the recombination of metallic vapors with CO/CO2 (in the collection zones) and/or to the formation of sub-products (carbides…).
The main missions of the work to be done during the post-doc are the following :
- Experimental evaluation and validation of defined recycling processes for oxidized metallic fuels using concentrated solar energy
- Detailed physico-chemical characterization of raw sources as synthesized combusted and recycled metallic particles
- Synthesis of metallic fuels recycled at adequate quantities to be directly used in the combustion tests
- On the basis of the experimental results, an integrated scheme for the sustainable, environmental-friendly preparation and recycling of metallic fuels will be defined in collaboration with the partners.
Unique concentrated solar furnaces facilities associated to a dedicated reactor (Sol@rmet) will be used to heat the metallic oxides in order to carry out the reduction process at PROMES-CNRS laboratory. Moreover a gas (CO/CO2) analysis will be done all along the process (in situ measurement) together with the high temperature measurement using an optical pyrometer.
- Experimental work on existing reactor at high temperature
- Modeling of the current reactor for extrapolation
- Design of a new reactor larger than the current one
- PhD in Process Engineering, or Chemical Engineering or Materials Science
- Knowledge in experimentation needed
PROMES-CNRS is a French laboratory belonging to the 'Centre National de la Recherche Scientifique (CNRS)' both located in Font-Romeu Odeillo (solar furnace) and in the University of Perpignan (Tecnosud site) composed of more than 150 people with 90 permanents.
Among the eight research groups of PROMES-CNRS involved in the main research areas of PROMES-CNRS laboratory linked to concentrated solar energy with two axes: Materials and Extreme Conditions and Transformation, Storage and Transport of Energy, the group MHTCS 'High Temperature Materials and Solar Fuels' managed by L. Charpentier is working for space activities and for the elaboration of new fuels by a solar route (hydrogen, metals particles).
The research objectives of the laboratory are to:
- Study solar energy conversion into heat, coldness, electricity, and hydrogen (energy carriers) using particularly thermal and thermochemical processes
- Qualify and improve high temperature materials, and elaborate new materials using concentrated solar energy
- Develop low environmental impact processes and long lifetime materials.
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