Development of a new intensified green process for the co-valorization of CO2 and cement / mining waste
Toulouse
CDD
Temps-plein
Il y a 14 jours
Offer DescriptionKeywords: Carbon Capture, Utilization and Storage, accelerated carbonation, attrition-assisted process, amino acids, kinetic study, physico-chemical characterizationContext:The acceleration of climate change prompts the search of viable solutions to eliminate anthropogenic GreenHouse Gases (GHG) such as CO2. The International Energy Agency has identified aqueous mineral carbonation as one of the most promising large-scale mitigation options. It reproduces what nature has done over geological time in just a few hours, offering favorable conditions and a higher reactive surface. It involves dissolving naturally abundant alkaline earth silicates or industrial wastes in CO2-acidified water, which then recombine to produce thermodynamically stable solid phases (solid carbonates and silica). The valorization of carbonation products as alternative building materials thus makes it possible to combine the mitigation of CO2 emissions, the valorization of waste and the preservation of natural resources.However, a major limitation of aqueous mineral carbonation lies in the formation of passivating layers that slow down or inhibit the solid dissolution (with typically less than 10% of material converted in 24h). The LGC Toulouse has overcome this bottleneck by developing a process that combines leaching with an attrition mechanism, enabling carbonation yields in excess of 80% to be achieved1,2. On the other hand, the ICBMS Lyon has demonstrated that CO2 capture by industrial amines or certain amino acids produces dynamic molecular systems with selective complexation and innovative catalytic properties3.The CARMIN project, funded by the Agence National de la Recherche (French National Research Agency) and carried out by the ICBMS, LGC and VICAT, an international cement group, proposes to hybridize these two carbonation activation solutions, which are currently being studied separately: a physical activation by the mechanical exfoliation of the leached layers formed by the (by-)products on the particle surface, and a chemical activation based on the catalytic effect of amino acid-based molecular complexes. The application targeted by this green process is the valorization of cement and mining wastes, such as concrete residues and slag (rich in Ca, Mg and/or Fe). It should also enable the separation of elements that may be undesirable or valuable elsewhere.In this context, the LGC Toulouse team is proposing a PhD thesis on the experimental study and modeling of the hybrid process at different scales, to investigate the possible synergy between the activation solutions and to optimize the operating parameters.Study description:The studies will be carried out in batch and flow reactors, operating under pressure on different scales (from 300 mL to several L) and equipped with multiple probes. They will focus on the dissolution and carbonation kinetics of mineral wastes, the advanced physico-chemical characterization of solid products using complementary analytical techniques (elemental analysis, electron microscopy, X-ray diffraction, X-ray photon and Raman spectroscopy, 29Si NMR, porosimetry, laser diffraction, etc.) to elucidate reaction mechanisms, and the measurement of extraction rates of metals in solution. Model materials of the target deposits will also be studied to gain a better understanding of the elementary mechanisms for magnesium and calcium silicates (while limiting the impact of other elements present in the waste).A thermo-kinetic model integrating experimental results will be developed, capable of predicting speciation in the liquid and solid phases and coupling the different implied kinetics (leaching, carbonation and attrition), so as to lead to a model of the whole hybrid process. In particular, a population balance model will be used, based on the determination of the grinding (attrition) and selection functions of the attrition system. It will serve as a basis for the process extrapolation and life cycle analysis to be carried out during the CARMIN project, with a view to its application on a larger scale.Supervision and contacts:The thesis will be carried out within the "Innovative Multiphase Reactor Engineering" (IRPI) department of the Chemical Engineering Laboratory. This research department studies the coupling between thermodynamics and various physico-chemical processes (chemical reaction, grinding and mechanical exfoliation, hydrodynamics, interfacial transfers, etc.) occurring within multiphase contactors, in order to propose new optimized technological solutions.It will be supervised by Dr. C. Julcour, Dr. F. Bourgeois and Dr. L. Cassayre, who have developed the attrition-leaching process as part of several projects (notably ADEME/CARBOVAL4 and ANR/BIOMECALIX5) relating to the valorization of CO2 by mineralization and the production of copper by hydrometallurgical treatment of chalcopyrite.Carine Julcour (LGC/IRPI), DR CNRS, ,Florent Bourgeois (LGC/IRPI), PR INPT/ENSIACET,Laurent Cassayre (LGC/IRPI), DR CNRS,References:(1) Julcour-Lebigue, C. et al. Chem. Eng. J. 2015, 262, 716-726. https//doi.org/10.1016/j.cej.2014.10.031(2) Bourgeois, F., et al. Front. Energy Res., section CCSU, 2020. .(3) Septavaux, J. et al. Nature Chem. 2020, 12(2), 202-212.(4) Dufourny, A. et al. Front. Clim. , section CO2 removal, 2022.(5) Dakkoune, A. et al. ACS Eng. Au 2023, 3, 3, 195-209.RequirementsResearch Field Engineering » Chemical engineering Education Level Master Degree or equivalentSkills/QualificationsCandidate profile:The recruited student should preferably have a solid background in Chemical Engineering with, in particular, skills in running experimental pilots and experimental planning. Experience in the operation of multiphase chemical reactors under pressure is desirable, as well as in the physicochemical characterization of liquid and solid phases. Knowledge of mineral grinding and leaching processes, as well as geochemical modelling, would be an advantage. Finally, a good level of spoken and written English is required.Languages ENGLISH Level GoodAdditional InformationSelection processApplication file (single pdf file):- Summary CV, including current professional situation and diplomas,- School curriculum and transcripts,- Research internship topic and letter of appreciation from the supervisor,- English level,- Cover letter showing the adaptation of the candidate's profile to the proposed subject.Application deadline: July 1st, 2024Work Location(s)Number of offers available 1 Company/Institute Laboratoire de Génie Chimique Country France City Toulouse Postal Code 31400 Street 4 allée Emile Monso GeofieldWhere to apply E-mailcarine.julcour@ensiacet.frContact CityToulouse WebsiteStreet4 allée Emile Monso Postal Code31400STATUS: EXPIRED