Optimisation of the structural and liquid water diffusion properties of carbons architected by 3D printing of biosourced resins for the development of solar evaporators

  • Épinal, Vosges
  • CDD
  • Temps-plein
  • Il y a 26 jours
Offer DescriptionThe countries of the Mediterranean basin produce around 97% of the world's olives, representing up to 3 million tons of olive oil per year. The various olive oil extraction processes generate huge quantities of solid and liquid waste. It is estimated that processing one ton of olives generates an average of 1 m3 of oil mill wastewater (OMWW). This project aims to treat and recover toxic OMWW in line with the principles of green and sustainable chemistry for a circular economy. Current regulations allow only a small proportion of these materials to be applied directly to land, and manufacturers are looking for other ways of managing this toxic liquid waste.The proposed solution is to use solar distillation, a process that has the advantage of having a low environmental impact, to treat the effluents from olive oil production in order to accelerate their evaporation/drying so that they can be better processed and recovered. The solar distiller developed for this project will consist of an evaporation cell and a condensation cell. The thesis proposal will be to develop the evaporation cell. The special feature of this evaporation cell is that it uses a porous 3D carbon matrix produced by 3D printing (stereolithography), after pyrolysis of biosourced resins. The role of this 3D matrix is to intensify evaporation performance by (i) increasing the exchange surface between the water to be purified and the surrounding air and (ii) capturing solar flux thanks to the carbon's high solar radiation absorption capacity.Promising initial evaporation trials have been carried out with these 3D evaporative matrices, but limitations in terms of the diffusion of liquid water within the porous structure have been identified. The main obstacle to the diffusion of liquid water is the small size of the pores on the surface of the porous structure (0.7 nm, whereas the core is of the order of 10 µm).The aim of the thesis will be to optimize the structural and liquid water diffusion properties of 3D carbon matrices for the development of solar evaporators. The work will involve developing solutions at several scales: * On a microscopic scale, the aim will be to develop biosourced resins that can control the structural properties (porosity, pore size, etc.) of the porous matrix. As these properties are directly correlated with liquid water diffusion performance, the pore size needs to be increased at the surface and reduced at the core. To achieve this objective, innovative resin formulations could be proposed, in particular with the addition of porogens. Another possibility is to improve the hydrophilic nature of the structures by post-treatment with CO2 or steam, or by chemical treatment (oxidation by acid-base treatment).
  • On a macroscopic scale, the design of the 3D matrix will be studied. A methodological approach of the experimental design type is envisaged to quantify the impact of certain parameters on performance, such as the height of the cell, the thickness of the strands allowing water to be transferred and the space between the strands.
Once the properties have been optimized, the 3D matrices will be integrated into a prototype in order to study the performance of the evaporation cell in the laboratory. The system will be studied using our experimental test bench. Initially, evaporation performance will be studied with pure water, then with nutrient- and salt-laden water to get closer to the OMWW context.In previous work, a numerical model was developed to simulate mass and heat transfer within the evaporation cell. It will be necessary to learn how to use and develop this model as a tool for optimizing evaporation performance. By going back and forth between the model and the experimental prototype, it will be possible to optimize the design and maximize performance.RequirementsResearch Field Chemistry » Other Education Level Master Degree or equivalentSkills/QualificationsThe candidate will join a research team specialised in materials science, the "Biosourced Materials" team from the Jean Lamour Institute (IJL, UMR CNRS 7198), housed at the ENSTIB premises in Epinal. He/she must have followed training in solid-state chemistry or materials science as a priority, but knowledge of additive manufacturing will be particularly appreciated. The candidate must demonstrate great ease with the materials processing and characterization tools (3D printer, UV-visible spectrometer, UV source, cone-plate viscometer and TGA / DSC) on which he/she will be trained to become quickly autonomous. Knowledge in computer-aided design (CAD), in numerical simulation, on natural substances, polymers and polymerisation processes will be a plus. He/she must be dynamic, curious and persevering to carry out the multiple syntheses, characterisations, tests and interpretations of the results, and demonstrate the ability to work in a team.Specific RequirementsOnly high quality applications will be considered: Master 2 average ≥ 14/20, 1st quartile, international experience required. Applicants who do not meet these requirements are asked not to submit an application.Highly qualified applicants are invited to send a CV and a motivation letter, together with diploma copies and/or marks obtained during the Master degree.Languages ENGLISH Level GoodAdditional InformationWebsite for additional job detailsWork Location(s)Number of offers available 1 Company/Institute Institut Jean Lamour / Université de Lorraine Country France City Epinal Postal Code 88000 Street 27, rue Philippe Séguin GeofieldWhere to apply WebsiteContact CityEpinal WebsiteStreet27, rue Philippe Séguin Postal Code88000 E-Mailvincent.nicolas@univ-lorraine.fralain.celzard@univ-lorraine.frSTATUS: EXPIRED

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