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École doctorale SIMPPé - Sciences et ingénierie des molécules, des produits, des procédés, et de l'énergie (Lorraine)

Overview
Works: 112 works in 112 publications in 2 languages and 112 library holdings
Roles: Other
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Most widely held works by des produits, des procédés, et de l'énergie (Lorraine) École doctorale SIMPPé - Sciences et ingénierie des molécules
Valorisation de résidus miniers riches en fer : Conception et développement d'un procédé de production de fer électrolytique à partir de matrices complexes by Abdoulaye Maihatchi Ahamed( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

L'augmentation de la démographie mondiale (de 2,5 milliards en 1950 à 10 milliards d'habitants en 2050 selon l'Organisation des Nations Unies) entraine une augmentation des besoins en métaux. Ces métaux proviennent des mines, mais leur production à partir des minerais engendre d'énormes quantités de résidus. Ces derniers occupent de grands espaces de stockage et contiennent encore des métaux qui peuvent être extraits. La valorisation de ces résidus permettrait non seulement de réduire leurs volumes et leurs empreintes écologiques, mais aussi et surtout de produire des métaux à forte valeur ajoutée pour répondre aux besoins des nouvelles technologies. Deux types de résidus riches en fer ont été étudiés dans ce travail afin d'extraire le fer et le zinc qu'ils contiennent par électrodéposition : les boues rouges et la jarosite. Dans le premier cas, il s'agit des résidus provenant de la production de l'alumine à partir du minerai de bauxite par le procédé Bayer (procédé alcalin). Le deuxième type de résidu, la jarosite, provient de la production du zinc par le procédé « jarosite » en milieu acide. Pour ce faire, deux approches expérimentales ont été mises en place. Une électrodéposition directe dans le cas de boues rouges : les échantillons sont directement mis en suspension dans une solution de NaOH 12,5 mol/L et le fer (sous forme d'hématite et/ou de goethite) est électrodéposé sur une cathode en graphite à une température de 110°C. Pour le cas de la jarosite, une démarche différente a été mise en place : (i) une lixiviation de la jarosite en milieu acide sulfurique, (ii) une lixiviation de blende pour réduire le fer ferrique en fer ferreux et enrichir le bain en zinc, (iii) une cémentation du cuivre par une poudre de zinc et enfin (iv) une étape d'électrodéposition d'alliage fer-zinc. Dans les deux cas de résidus, plusieurs paramètres opératoires ont été testés afin d'optimiser les rendements de lixiviation, de cémentation, la qualité des dépôts et les rendements faradiques. En ce qui concerne les boues rouges, les meilleurs rendements faradiques (72%) ont été obtenus pour un ratio solide/liquide de 1/3 (g/mL), une concentration en NaOH de 12,5 mol/L, une densité de courant de 41 A/m² et une température de 110°C. Les dépôts du fer électrolytique, analysés par ICP-AES, DRX, MEB/EDX, présentent une pureté supérieure à 97% massique en fer. Pour la jarosite, les meilleurs rendements de lixiviation (en zinc et en fer étaient de 73% et 70% respectivement) ont été obtenus pour une concentration d'acide sulfurique égale à 1,5 M, un rapport solide/liquide 1/10 (g/mL) et une température de 80°C pendant 7 heures. Les essais d'électrodéposition ont permis de produire des alliages zinc -fer à différentes teneurs en fer. Les rendements faradiques obtenus dans les conditions optimales (densité de courant de 800 A/m² et une température de 20°C) étaient de l'ordre de 89%. Les résultats obtenus dans cette étude confirment la faisabilité technique d'électrodéposition du fer et d'alliage fer-zinc à partir des matrices complexe. Cela ouvre une nouvelle alternative à la valorisation des résidus miniers par la technique d'électrodéposition des métaux
Étude critique de quelques techniques expérimentales d'évaluation de la coulabilité des poudres by Assia Saker( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

In industrial sectors, such as chemical, pharmaceutical or food industries, poor flowability of powders is often the causes of process malfunction. Poor flowability can lead to the blocking of powders in a silo, dosing and filling problems, or even bad quality on final product. To ensure proper process operation, it is therefore necessary and essential to evaluate the flowability of powders used. For this purpose, several experimental techniques such as angle of repose devices, shear cells or powder packing devices can be used. Flowability indices can then be defined in order to classify the powders according to the flow quality. Experimental tests have been carried out on several types of powders and the first results have shown that the transition from one technique to another can modify or even reverse the classification of the powder flowability. Indeed, according to the techniques studied, powders are subjected to different mechanical stresses and therefore the choice of the technique must be adapted to the real case of study. In this work, we were particularly interested to the evaluation of powders flowability from compaction devices. The work carried out has shown that the dynamic parameters (amplitude and frequency of taps) greatly influence the classification of powders flowability. From an energy approach, it has been shown that the evaluation of the flowability from Hausner ratio can be given by a compaction technique only if it achieves a value of energy required to obtain a maximal compaction of the particles. Finally, an implementation study of flowability evaluation techniques was carried out in the field of formulation by focusing on the quantitative evaluation of the influence of a glidant
Kinetic study of ester biofuels in flames by Artëm Dmitriev( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

Global progress all over the world requires a variety of clean energy sources. Liquid ester-based biofuels seem to be very effective in this context since they are easy to use in modern vehicles, they can be produced from a variety of renewable resources, and they provide environmentally friendly combustion characteristics. In this regard, fatty acid ethyl esters (FAEEs) are considered as a promising class of biofuels. The main goal of this thesis was to develop an updated chemical kinetic mechanism of combustion of light FAEEs up to ethyl pentanoate and validate it against the new experimental data on chemical speciation in low and atmospheric pressure premixed laminar flames. The flames fueled by three FAEEs, ethyl acetate, ethyl butanoate and ethyl pentanoate, were investigated by means of molecular-beam mass-spectrometry and gas-chromatography. More than 40 stable and intermediate species including radicals were detected and quantified in the flames. A comprehensive analysis of the developed mechanism was performed. The thesis consists of 3 chapters. In the first chapter a review of literature is presented. The most important experimental and theoretic studies on FAEEs are discussed. The second chapter presents an overview of experimental and simulation methods used in the work. Details on the mechanism development are also provided in this part. The last chapter present experimental and modeling results on the esters studied in comparison with the literature kinetic mechanisms
Comportement au feu du matériau bois : auto-inflammation, dégradation et auto-extinction by Lucas Terrei( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

The construction of positive energy and low carbon footprint buildings is a real response to the environmental issues and challenges of the coming decades. An increasing number of high-rise building construction projects made largely of wood are either under study or under construction. A key issue for the construction of such buildings is the fire behavior of these structures. Indeed, when the wood is subjected to a high heat flux, it will degrade and it can self-ignite. Conversely, in certain conditions, wood can self-extinguish. However, the bibliography shows the disparity concerning experimental results for a same material subjected to a given test such as the cone calorimeter. The results on the wood extinction remain limited in view of recent research carried out on this phenomenon. The aim of the thesis is to experimentally study the self-ignition, degradation and self-extinction of the wood material used in buildings. For this, many tests at different scales have been performed to examine the ability of the wood material to self-ignite or self-extinct under prescribed conditions. A total of 600 tests, were performed in vertical orientation and allowed to consolidate results with a statistical approach. A dedicated experimental setup has been deployed on each experimental device studied: an infrared camera providing to measure the surface temperature of the samples when they are subjected to a heat flux, two fast cameras (visible and infrared) in order to record the location and the auto-ignition mechanisms and very thin thermocouples embedded in the wood to measure the temperature evolution in the material according to fixed conditions. Results showed that for the auto-ignition (i.e. without pilot), the notion of ignition temperature of the material could be questionable when the ignition occurs at short times. Indeed, the flame appearance is, in most of the experiments, at a distance far from the exposed surface to the heat flux. The ignition mechanisms do not depend on the surface temperature but on the gas / air mixing conditions as well as the mixture temperature. The auto-ignition surface temperature makes therefore sense only for long auto-ignition times, for which ignition occurs close to the surface. The samples degradation depends on many factors: sample orientation, sample humidity, wood species, oxygen concentration in the atmosphere. The effect of these parameters was considered in this work. A particular attention was focused on the establishment of a metrology aimed at obtaining precise and accurate measurements. Very thin thermocouples, embedded in the sample and oriented parallel to the isotherms allow a better estimation of the temperature and were therefore used. Finally, a new experimental device based on two cones calorimeter arranged on a sliding table system was set up and made it possible to determine simple criteria for wood self-extinguishment at small scale
Étude des transferts de chaleur dans un film ruisselant à instabilités de surface par des méthodes de fluorescence induite par laser by Romain Collignon( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Thin wavy liquid films are used in many industrial applications as heat and mass transfer promoters, for example they are used in plate heat exchanger or in cooling columns of nuclear power plants. However, the mechanisms of transfer intensification related to the instabilities are still poorly understood and models do not allow to account for all physical phenomena and their coupling. The aim of this work is to study experimentally the intensification of heat transfers between a heated flat inclined wall and the liquid film, when it is traversed by 2D waves on its surface. For this purpose, an experiment has been developed, allowing to impose perturbations on a water film flowing on a thin titanium sheet, heated by Joule effect. Two non-intrusive measurement techniques, based on the laser-induced fluorescence (LIF) technique with two dyes and two colors (2c2d-LIF) were performed to characterize heat transfer. The temporal evolutions of the local average temperature and thickness of the film were measured at one point using a point LIF measurement. A continuous laser radiation, with a wavelength of 532 nm, is used to excite the fluorescence of the seeded liquid by a couple of fluorescent tracers. The intensity of the fluorescence is detected on two different spectral bands: the ratio of the two intensities makes it possible to determine the average temperature of the volume of the probed film, while the intensity measurement makes it possible to obtain the thickness of the film. The use of a pulsed laser allows to freeze the dynamics of the film. Thus, the simultaneous use of two CCD cameras allows to apply the 2c2d-LIF technique in order to obtain an image of the instantaneous temperature field inside the wavy liquid film. The use of a fluorescence intensity ratio on two spectral bands allows to get rid of poorly controlled parameters related to the fluorescence intensity such as the variation of the laser intensity in the film, induced by the deformation of the free surface of the film. A reconstruction algorithm provides the spatio-temporal evolution of the temperature field over the period relative to a wave. The association of these techniques with the measurement of the wall temperature by thermocouples allows to correlate the presence of surface waves to the intensification of heat transfers. The results obtained allow to highlight the influence of convective mixtures induced by surface waves on heat transfers, as a function of parameters such as the frequency of waves and the volume flow rate of the liquid
Study of the separation by organic solvent nanofiltration of diluted solutes using commercial, dense and porous membranes and their derivatives by deposition of polyelectrolyte nanolayers by Mahbub Morshed( )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

The objective of this study was to improve the OSN separation performance of commercial membranes for metathesis applications in which highly diluted catalysts are used. In this work, commercial polymeric membranes were first studied to characterize their performance in organic media using very dilute solute-solvent binary mixtures. Based on a literature review, it was shown that the PERVAP4060 membrane, of which PDMS is the dense active layer, was a promising candidate for organic solvent nanofiltration (OSN). As a porous membrane, the AMS and PAN commercial supports have also been taken into account. In this study, we considered the modification on the surface to improve the separation properties of polymeric OSN membranes. Ar/O2 plasma and/or polyelectrolytes multilayers were used for the preparation of new prototype membranes. Unmodified and modified membranes were tested under OSN conditions using binary feed mixtures. Several highly dilute solutes, organophosphorus ligand R-BINAP, phase transfer catalyst ToABR, and linear alkanes have been studied. Both R-BINAP and ToABR were used in the range of 0.0001 to 0.5% by weight, and most experiments were subsequently performed with 0.05% solute concentrations in toluene. It has been shown that PDMS can retain 80% R-BINAP and about 93% ToABr in toluene. After modification by the LBL deposition, the rejection is improved with the modified PERVAP4060 membranes, leading to an 88% rejection of R-BINAP with a deposit of 10 PAH / PSS polyelectrolyte bilayers at the surface and this rejection being able to reach 95% when the number of bilayers is 20. ToABr rejection increases to 97% with the ten bilayered membranes. The performance of the membrane was studied under different pressures of between 1 and 40 bar; the high rejection, still observed in these OSN conditions, strongly supports a solution-diffusion transfer mechanism through the PDMS. The treatment of ternary mixtures mimicking the catalyst/solute/ solvent mixture corresponding to the hydroformylation has also been studied; no evidence of coupling was detected, and the highest retention remained unchanged. On the other hand, the improvement of the rejection also observed from the porous membranes after modification. The rejection of C44 in the AMS was reached 75% after modification by tention10 bilayers of PDDA / PSS, whereas it was only 25% before modification. In the modified PAN, the rejection of the solutes obtained is in the range of 37 to 50%, whereas it was only 3 to 7% by weight before modification. The disadvantage of the porous membrane, however, is the sharp decrease in flux after the deposition of the multiple layers
L'étude de l'influence de la structure chimique des additifs sur le contrôle de la réactivité des carburants by Minh Duy Le( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

Les sociétés modernes ont besoin de moteurs à combustion interne plus propres et plus efficaces. Cette contrainte entraîne une évolution significative des systèmes de combustion et de la formulation de carburants. L'adéquation moteur-carburant est l'élément clé à optimiser pour atteindre cet objectif. Parmi les paramètres en jeu, la réactivité du carburant est une caractéristique de premier ordre. C'est l'une des raisons en lien avec l'utilisation des additifs. Ils permettent au carburant d'améliorer l'ensemble de ses propriétés notamment vis-à-vis de la combustion. Cependant, le choix et l'utilisation des additifs se heurte encore à un manque de compréhension de leur mécanisme d'action. Dans ce contexte, cette thèse vise à mieux comprendre l'effet chimique des additifs sur la réactivité dans la phase gazeuse. Trois additifs, dont un booster de cétane, un booster d'octane et un antioxydant sont considérés : le 2-ethylhexyl nitrate (EHN), le ferrocène et le 2,4 xylénol respectivement. L'effet chimique de ces additifs sur la réactivité d'un carburant modèle contenant 35 % de n-heptane et 65 % de toluène en volume a fait l'objet d'une étude expérimentale et numérique. Des expériences ont été menées à l'aide de trois équipements : un tube de choc, une machine de compression rapide et un brûleur à flamme plate. L'utilisation de ces équipements permet d'explorer la variation de la réactivité dans des conditions variables représentatives du fonctionnement des moteurs. En parallèle, un modèle cinétique détaillé a été élaboré en s'appuyant sur des données récentes de la littérature. L'accord satisfaisant entre les expériences et les simulations permet de proposer des hypothèses quant à l'effet chimique des additifs
Caractérisation des usinages robotisés : Application aux processus de transformation du matériau bois by Oussama Ayari( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Nowadays, the robotization of wood machining remains a complicated and uncommon task. This is also due to the significant constraints to which the use of an industrial robot (also known as anthropomorphic or polyarticulated) is subject. These particularly concern operations that require a high degree of precision and agility. Indeed, the forces exerted on the robot's articulations and on the tooling come up against the insufficient natural rigidity of polyarticulated robots. This causes the machine to lose its performance in terms of output and efficiency and degrades the quality of machining. In addition, the variable properties of the wood material do not make the polyarticulated robot the ideal candidate for material removal machining processes. In order to answer this problem, we seek, through this thesis, to improve the machining of robotized wood by taking into account the major technological difficulties: natural rigidity, dimensional quality of machining and cutting forces and interaction between them. Thus the difficulties related to the wood anatomy: Heterogeneity, anisotropy, fibrous texture and singularities. To solve this problem we used a numerically controlled (CNC) machine tool and an anthropomorphic ®Kuka robot equipped with a high-speed machining engine. We instrumented our experimental bench with a force measuring chain and a digital measuring table to quantify the dimensional errors of the machined profiles. Three wood materials are machined: Hardwood (Beech), softwood (Fir) and derived timber (MDF). The results obtained show that there is a direct proportional relationship between cutting forces and degradation of dimensional quality, regardless of the machine used. The higher the forces applied to remove the material, the more the tracking performance of the end effector decreases. In terms of system stability, measurements have shown that the farther the tool works from the robot base, the more the cutting forces fluctuate and the more the dimensional quality deteriorates. This becomes more pronounced when material heterogeneity and density are high. As a result, the robot is less stable and its performance in terms of repeatability in series production degrades. Fluctuations in stress and degradation of dimensional quality are intensified by changing the cutting mode. Cutting forces increase by a factor of 8 when the tool works perpendicular to the wood grain.The case of material-related peculiarities is discussed. Indeed, measurements show a rapid and sudden jump in forces which multiplies by 3 when the cutting edge passes through a knot. This leads to splinters and cracks in the material and degrades the orthogonality of the cut. The variation of the robot feed rates from 4m/min to 9m/min in beech machining resulted in damage to the machined surface in the form of material ripples and splinters due to deviations in the tool path. The same experiments on the variation of the robot feed rates are carried out on other species such as larch (softwood) and oak (hardwood) to study the machining quality. The results found are similar to those obtained previously (material splinters, tool path deviations and cracks)
Modification chimique des extractibles de bois : application à la protection du bois et des matériaux métalliques by Wissem Sahmim( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Within the framework of this thesis, we are interested in the design, synthesis and characterization of the physicochemical properties of lipophilic derivatives of wood extractives. We have thus considered modifying the structure of three flavonoids whose resource is important from different wood species: catechin, mesquitol and naringenin to incorporate additional functionalities. The applications reported here mainly deal with the protection of materials like wood and corrodible metals. With respect to wood preservation, it seems possible to consider different strategies to inhibit the wood degradation related to fungi on wood. Impregnation of antioxidant compounds such as lipophilic polyphenols on wood can limit the effects of radicals or other oxidants used and generated by rots. The second intended application is the protection of metallic materials. Indeed, the use of natural antioxidants as a corrosion inhibitor replace inorganic inhibitors or organic molecules (polyamines, imidazole...), because their production is expensive and toxic. The grafting of a hydrophobic hydrocarbon chain on polyphenols which have antioxidant properties allows the formation of protective films on the material
Dimensionnement et étude expérimentale d'un vaporiseur à milli-canaux by Guillaume Henry( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

The ever-growing awareness of the impact of human activities on the environment makes industries find environmentally friendly alternatives. In the automotive sector, the development of less polluting cars using hydrogen as fuel is an example. To successfully promote this type of vehicles to people, the providing network of hydrogen has to be set up. To tackle the challenge of this deployment, Air Liquide, through the FAIR project (Additive manufacturing for the intensification of reactors), aims to intensify the Steam Methane Reforming process in order to develop small mobile hydrogen production unit. Inside this process, a particular step, the water vaporisation, has to be intensified. To study this intensification, an experimental test bench and a vaporisation module are sized, assembled and instrumented in the Reactions and Chemical Engineering Laboratory (LRGP) in Nancy. The test bench uses a hot oil convection to vaporise the water. The vaporisation module, designed as a milli-structured plate heat-exchanger, has a window enabling the visualisation and the recording of the boiling water hydrodynamics with a high-speed camera. Four milli-structured plates are tested: two of them have 10 semi-circular straight channels either mechanically engraved of made by additive manufacturing, the third plate has various shapes of engraved channels and finally the fourth plate has 7 engraved straight channels with triangular cavities. An innovative method for the post-treatment of high-speed videos is developed in order to produce Spatio-Temporal Diagrams (DST) showing the spatial evolution of liquid-vapor interfaces by the time inside a channel. The exploitation of this new tool enables the determination and the description of boiling phenomena (spontaneous bubble nucleation, liquid oscillations), the understanding of the boiling events chronology and the characterisation of flow regimes (bubbly, slug, churn, annular flow and dry out of the channel). Moreover, a quantitative exploitation of the DST is possible such as the local vapor quality needed for the drawing of flow regime map. Thanks to the measurement of various operating data on the test bench, the characterisation of the heat losses is done in order to assess the vapor quality of the water flow outgoing the vaporiser by a heat balance. The two-phase heat-transfer coefficients are also assessed. Finally, a methodology of milli-structured vaporiser made by additive manufacturing pre-sizing is put forward. It is based on two case-study on the intensification of water vaporisation in a small mobile hydrogen production unit and in a standard SMR process
Étude de faisabilité de la valorisation en bioraffinerie de biomasses issues de phytotechnologies : cas d'une plante hyperaccumulatrice (noccaea caerulescens) et d'un ligneux (salix viminalis) by Zahra Menana( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Phytoremediation is a concept for the depollution and rehabilitation of soils and/or industrial wastelands contaminated by metal trace elements (MTEs), using plants to absorb or immobilize contaminants in the presence of microbial organisms in the rhizosphere. This technique results in a more or less contaminated biomass production that must be treated and also recovered. However, the presence of MTEs can be an issue in a biorefinery conversion approach. To address this question, two species were studied: an hyperaccumulator herbaceous plant (Noccaea caerulescens) and a woody plant (Salix viminalis). Two pre-treatments were selected for this study: steam explosion and organosolv pre-treatments, applying different operating conditions, in order to (1) monitor the distribution of MTEs during the process, (2) purify lignocellulosic material and (3) evaluate the effect of MTEs on subsequent enzymatic hydrolysis and fermentation steps. For organosolv pretreatment, most of the MTEs are recovered in the solid cellulosic residue while by steam explosion, MTEs are mostly extracted in the aqueous effluents of the treatment. The presence of MTEs in cellulosic pastes and hydrolysates does not show a significant effect on the kinetics of enzymatic hydrolysis and fermentation. Concerning specifically Noccaea caerulescens, the plant contains relatively high levels of pectins, which opens up interesting prospects for the valorization of this plant through the production of a biopolymer of industrial interest. Finally, the results obtained show that it would be possible to combine soil rehabilitation and biorefinery valorization of biomasses from phytotechnologies for either bioethanol production or the production of platform molecules
Filtration d'aérosols de suie en présence de vapeur et/ou de gouttelettes d'eau by Charlotte Godoy( )

1 edition published in 2019 in French and held by 1 WorldCat member library worldwide

One of the most frequently used methods to purify air contaminated by particles, in many industrial processes, is filter media. These collective equipment for protecting people and the environment are proven in terms of initial efficiency, but their behavior over time remains difficult to predict. This is all the more noticeable when these devices are confronted with a biphasic aerosol composed of solid and liquid particles. These situations can be encountered during metals machining, pesticides spreading or even during fires in confined areas such as nuclear power plants. The proposed study will aim to establish the performance of a fibrous media with respect to biphasic aerosols with nanostructured solid particles and droplets (submicron or micron-sized). If the filtration of solid aerosols or liquid aerosols is relatively well documented in the literature, no study has been interested in this problem of biphasic aerosols. For high solid / liquid ratios, the time course of the pressure drop should be close to solid aerosols filtration evolution, ie a quasi-linear increase over time. In the case of an aerosol predominantly made up of droplets, a constant pressure drop overtime, characterized by a state of equilibrium between the mass flow rate of collected droplets and the flow rate of liquid drained on the downstream face of the filter, could be considered . But what about the evolution of the pressure drop between these two extremes? The determination of the temporal evolution of the collection efficiency is also uncertain and should be regarded as a real metrological challenge
Estimation d'énergies de GIBBS de solvatation pour les modèles cinétiques d'auto-oxydation : développement d'une banque de données étendue et recherche d'équations d'état cubiques et SAFT adaptées à leur prédiction by Edouard Moine( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Les réactions d'oxydation d'hydrocarbures en phase liquide (aussi appelées auto-oxydation) jouent un rôle essentiel dans un grand nombre de procédés de l'industrie pétrochimique car elles assurent la conversion du pétrole en composés chimiques organiques valorisables. Elles régissent également la stabilité à l'oxydation des carburants (vieillissement) et des produits chimiques dérivés du pétrole. Ces réactions d'oxydation en phase liquide relèvent de mécanismes radicalaires en chaîne impliquant des milliers d'espèces et de réactions élémentaires. La modélisation cinétique de tels systèmes reste actuellement un défi car elle nécessite de disposer de données thermodynamiques et cinétiques précises, qui sont rares dans la littérature. Le logiciel EXGAS, développé au LRGP, permet de générer automatiquement des modèles cinétiques détaillés pour des réactions d'oxydation d'hydrocarbures en phase gazeuse. Qu'il s'agisse d'une phase gazeuse ou liquide, les réactions élémentaires mises en jeu sont de même nature et la méthodologie de génération du mécanisme est la même. Pour passer d'un mécanisme en phase gaz à un mécanisme en phase liquide il convient d'adapter les valeurs des constantes d'équilibre et de vitesse (appelées constantes thermocinétiques) des réactions du mécanisme. L'objectif de cette thèse est de proposer une méthode pour corriger les constantes thermocinétiques de la phase gaz pour qu'elles deviennent applicables à la phase liquide. Cette correction fait intervenir une grandeur appelée énergie de GIBBS de solvatation molaire partielle. Une analyse de la définition précise de cette quantité nous a permis de montrer qu'elle s'exprime simplement en fonction d'un coefficient de fugacité et d'une densité molaire. Nous avons ensuite relié cette grandeur à des quantités thermodynamiques mesurables (coefficients d'activité, constantes de HENRY ...) et nous nous sommes appuyés sur toutes les données qu'il nous a été possible de trouver dans la littérature pour créer la banque de données expérimentales d'énergies de GIBBS de solvatation molaires partielles la plus complète (intitulée CompSol). Cette banque de données a ensuite servi à valider l'utilisation de l'équation d'état UMR-PRU pour prédire ces énergies. Les bases d'une équation d'état de type SAFT, au paramétrage original, développé dans le cadre de cette thèse, ont été posées. Notre objectif était de simplifier l'estimation des paramètres corps purs de cette équation d'état en proposant une méthode de paramétrage ne nécessitant aucune procédure d'optimisation, claire et reproductible, à partir de données très facilement accessibles dans la littérature. Cette équation a été utilisée pour estimer les énergies de GIBBS de solvatation molaires des corps purs et les énergies de GIBBS de solvatation molaires partielles de systèmes {soluté+solvant}. Enfin, ces méthodes d'estimation des énergies de GIBBS de solvatation molaires partielles ont été combinées au logiciel EXGAS afin de modéliser l'oxydation du n-butane en phase liquide
Traitement des eaux usées dans des bioréacteurs multitrophiques grâce à des flocs de microalguesbactéries valorisables en biogaz by Olfa Beji( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

The biological treatment of urban and industrial wastewaters represents a process with a negative impact on the environment and on climate change through the emission of greenhouse gases (GHG), particularly CO2. In the presence of light, microalgae-bacteria flocs (MaB-flocs) have been integrated into photobioreactors with fixed biomass to ensure a sustainable wastewater treatment without O2 supply and CO2 release. The entrapment of flocs in PVA-alginate beads has shown the effect of physicochemical and hydrodynamic conditions on the elimination of pollutants and the multicellularity evolution within multi-scale bioreactors. In addition, the immobilization of biomass on biodegradable olive carriers and on PVC disks provided a better performance of fluidized bed and rotating discs bioreactors, respectively, for the bioremediation of wastewater. The properties of the supports (porosity, roughness, and structure) and the hydrodynamic behaviors have favored the attachment of multitrophic biofilms. Biofilm development shows the effect of multitrophic interactions between microalgae and bacteria on the organic compounds (COD) and nutrients (ammonium and phosphorus) removals. The MaB-flocs biomass was recovered and reused for the treatment of the digestate and to improve the production of biomethane by anaerobic co-digestion. This integrated multitrophic technology makes it possible to obtain zero wastes at the end of the process
Synthesis of enantiopure 3,4-dihydro-2H-1,4-benzoxazine analogues for potential biological applications by Hong-Ngoc Pham( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

This work describes the syntheis and conformational analysis of enantiopure 1,4-benzoxazine-based pseudodipeptides and pseudotripeptides. Enantiomers of ethyl 2,3-dibromopropionate and ethyl 3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate are obtained by two strategies (i) via enantioselective synthesis and (ii) via preparative HPLC enantioseparation of racemate on multigram scale. Because of the racemization process during the enantioselective synthesis, preparative HPLC enantioseparation on racemates are successfully applied to afford enantiomers with high enantiomeric purities (ee ≥ 99.5%). Both enantiomers of the 1,4-benzoxazine compound are used to design new 1,4-benzoxazine-based pseudopeptides via peptide coupling reactions on C- and N-terminal extremities. Their conformational behaviour in solution and solid states are investigated by spectroscopic (IR, NMR) and X-Ray diffraction analyses. The results indicate (i) a predominant C5 pseudocycle involving a lone pair of electrons of oxygen in 1,4-benzoxazine ring with NH group from C-extremity elongation and (ii) a slight influence of the absolute configuration at C2 position of 1,4-benzoxazine scaffold and the side chains of amino acids
Modélisation et développement de diagnostics optiques pour la caractérisation de gouttes surfondues en écoulement ou en interaction avec un substrat sous-refroidi by Mehdi Stiti( )

1 edition published in 2020 in French and held by 1 WorldCat member library worldwide

Les phénomènes de givrage qui se produisent sur les aéronefs en vol peuvent constituer un danger majeur dans l'aéronautique. Les principaux problèmes de sécurité qui en résultent sont une visibilité réduite, un blocage des tubes de Pitot et une réduction des performances aérodynamiques. Dans ce contexte, les aéronefs doivent être certifiés pour différentes conditions de givrage susceptibles d'être rencontrées, notamment en lien avec la présence de gouttes surfondues de diamètres supérieurs à 50 µm dans l'atmosphère. Les étapes de certification sont réalisées à l'aide d'essais normatifs en soufflerie givrantes permettant de recréer des conditions aéronautiques givrantes proche de celles rencontrées en vol. Les objectifs des travaux présentés dans ce manuscrit portent sur la mise en œuvre d'une nouvelle technique optique basée sur la Fluorescence Induite par Laser (LIF) pour la caractérisation de gouttes surfondues : température, détection de leurs états (i.e. liquide, solide ou mixte), caractérisation des gouttes en phase mixte et dynamique du front de solidification dans une goutte impactant un substrat sous-refroidi. Une première technique de LIF, mettant en jeux deux traceurs fluorescents et trois bandes spectrales de détection, permet de mesurer ponctuellement la température de gouttes surfondues en écoulement ainsi qu'estimer la fraction de glace contenue dans une population de gouttes en écoulement. Des mesures réalisées dans des conditions voisines de celles rencontrées en aéronautiques ont été réalisées dans une soufflerie givrante de la DGA Essais-Propulseurs et ont montré la difficulté de reproduire des conditions aéronautiques givrantes réelles (gouttes à l'équilibre thermique avec la phase porteuse). Une seconde technique basée sur l'Imagerie rapide de fluorescence induite par laser (PLIF) a été développée pour l'étude de la solidification d'une goutte impactant un substrat sous-refroidi. Cette nouvelle méthode de PLIF permet d'accéder, pour la première fois, à la dynamique et la morphologie du front de solidification à l'intérieur de la goutte. L'étude a porté sur des impacts de gouttes sur un substrat sec et sur un substrat recouvert d'une couche de glace. Le deuxième cas permet de s'affranchir du phénomène de surfusion de l'eau et donc du caractère aléatoire du déclenchement de la solidification. Les mesures ont montré que l'évolution du front de solidification et les caractéristiques de la pointe formée par la goutte en fin de solidification étaient dépendantes de la nature du substrat (conductivité thermique) et de l'angle de contact goutte/substrat
Optimal Helical Tube Design for Intensified Heat / Mass Exchangers by Omran Abushammala( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

The search for technological solutions aimed at minimizing the size of a device, known as intensification, is a classic objective of process engineering. In this thesis, the intensification possibilities offered by helical tubes are studied, both for heat and mass exchangers. The use of helical tubes instead of straight tubes is indeed of interest both in terms of increasing the exchange surface per unit volume between the two fluids circulating in the exchanger and by the possibility of increasing the transfers by generating Dean vortices in the tubes. A set of CFD (Computational Fluid Dynamics) type simulations was carried out and compared with experimental results. In the end, on the basis of a systematic approach using correlations, a volume reduction of a factor of 8 was obtained, both for heat exchangers and for membrane contactors
Traitement de minerais de fer par lixiviation alcaline suivi de leur électrolyse en milieu alcalin by Vincent Feynerol( )

1 edition published in 2018 in French and held by 1 WorldCat member library worldwide

Un procédé innovant de production de fer par électrolyse d'une suspension d'oxydes de fer en milieu alcalin concentré est développé au centre de recherche d'ArcelorMittal de Maizières-lès-Metz. Ce procédé s'il atteignait la maturité industrielle permettrait de réduire significativement les émissions de dioxyde de carbone associées à l'industrie sidérurgique, en remplaçant le carbone utilisé comme agent réducteur dans les hauts-fourneaux par de l'électricité. Bien que ce procédé permette la production de fer à partir d'hématite commerciale (Fe2O3) à une densité de courant de l'ordre de 1000 A.m-2 avec une efficacité faradique supérieure à 80%, une dégradation des performances est systématiquement constatée lors de l'électrolyse de minerais de fer. Les impuretés majoritaires de ces minerais sont les oxydes et hydroxydes d'aluminium et de silicium, des composés solubles dans la soude concentrée. Ces composés pourraient donc être à l'origine de la baisse de réactivité observée lors de l'alimentation du procédé par des minerais de fer. Ainsi afin de tenter d'améliorer les performances de l'électrolyse alcaline à partir de minerais, des traitements de lixiviation alcaline sur un minerai défini ont été effectués dans cette thèse. La réactivité des minerais avant et après traitement a été comparée par chronoampérométrie. Bien que suite à l'élimination de ses composés alumineux, le minerai traité ait vu son rendement faradique réhaussé à environ 80% pour une valeur avant pré-traitement de 65%, sa densité de courant est restée deux fois moins élevée que celle de l'hématite pour une même tension électrique appliquée. Des expériences d'ajout d'ions aluminates et d'ions silicates lors de l'électrolyse d'hématite pure n'ont de plus eu pratiquement aucun effet indésirable sur son électrolyse. Les diverses expériences conduites dans cette thèse laissent supposer que les impuretés traitées n'ont que peu d'influence sur la réactivité des minerais. Le procédé est en revanche très sensible à la granulométrie des particules de minerais. Par ailleurs de forts phénomènes d'agglomération, qui n'ont pas lieu avec les oxydes de fer purs, ont été constatés lors de mesure de granulométrie du minerai étudié. Ainsi les expériences réalisées laissent supposer qu'un autre phénomène, probablement lié à la granulométrie secondaire des minerais en milieu alcalin concentré, soit à l'origine de la baisse de réactivité observée lors de leur électrolyse. Parallèlement une analyse thermodynamique avancée a été menée afin de déterminer les meilleures conditions théoriques de pression, de température et de concentration en NaOH pour effectuer l'électrolyse de l'hématite. La solubilité des composés de la gangue a été représentée avec des équations de Pitzer, et de nouveaux paramètres ont été calculés pour les interactions Na-SiO3-Al(OH)4. Cette étude thermodynamique a permis la conception et le pré-dimensionnement d'une étape de traitement des minerais par lixiviation alcaline
L'approche Urban Living Lab pour insuffler l'innovation en urbanisme ? Contribution à la conception d'une ingénierie de pilotage de l'innovation urbaine : application à l'Opération d'Intérêt National d'Alzette Belval by Jonathan Lacroix( )

1 edition published in 2019 in French and held by 1 WorldCat member library worldwide

The urban development project is confronted with increasingly complex territorial and urban problems. How then can we enrich or even renew practices by experimenting with new configurations of actors, methods and tools? Solutions will be sought here in the field of urban innovation, which covers a wide range of initiatives, including method innovation in urban planning. In this theoretical and operational context calling for experimentation, the research approach followed aims to link the potential offered by certain innovative practices with the needs of urban planning. The Urban Living Lab project mode makes it possible to manage a multi-stakeholder and collaborative space and innovation process. The conduct of research and intervention in the context of the Alzette Belval National Interest Operation experimented with the integration of an Urban Living Lab approach into the governance, management and operational processes of an urban development project. This research work leads to the identification of the potential of the Urban Living Lab in terms of dialogue between the processes of project management of an urban development project and an innovation process producing actionable knowledge. Experience shows the ability of the Urban Living Lab approach to renegotiate the governance boundaries of the urban development project and to ensure that it is anchored in territorial governance
Characterization of gas-liquid hydrodynamics and mass transfer in SMX static mixers by Marco Scala( )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

The mixing of two or more fluids is a rather common operation in all industrial processes. The main target of the mixing is to increase the interface area between phases in order to improve mass and heat transfer and facilitate then chemical reaction. Among the multiphase mixing stands out the gas liquid dispersion. The aim of the present work is to examine a specific type of mixers, namely the static mixer. Static mixers are located into a housing or pipeline to ensure a high blending of fluids. They are usually made by a series of inserts, in turn designed by holes, helical elements and oblique blades. These elements cause local accelerations and stretching of the fluid currents to reach a high mixing efficiency. The wide applications of static mixers in numerous industrial processes require better knowledge of the hydrodynamics in these devices. The gas-liquid flow pattern through a Sulzer static mixer SMXTM mounted in a vertical cylindrical tube was investigated in this study. The main goal was to assess the performance of the Sulzer static mixer SMXTM for gas-liquid applications in industrial processes. Experimental data were collected from two main optical techniques, Backlight Shadowgraph Technique (BST) and Particle Image Velocimetry (PIV). 3D-printed static mixers were manufactured using transparent plastic in order to provide optical access. Three different liquids were used as the continuous phase, namely water, water with SDS and normal-heptane. The liquid phase was kept stagnant during the experiments. Five different lengths of mixers (with 1, 2, 5, 10 and 15 elements respectively) and several gaseous nitrogen flow rates from 1 to 10 l/h were analysed. The behaviour of the simple tube without mixing device, acting like a bubble column, was investigated as a reference, for comparison purposes with the SMXTM. Bubble diameter distributions at the inlet and outlet of the SMX mixers were evaluated. The velocity fields inside the mixers were quantified. The gas hold-up was also measured. The oxygen transfer performance in the SMX static mixer in air/water mixture was assessed by measuring the overall oxygen transferred. The mass transfer coefficient to the interfacial area kLa was determined and proved to be larger in the mixer. Volume-of-fluid numerical simulations of the mixer were performed with OpenFOAM. These 3D simulations were mainly focused on the behaviour of the SMX in an organic system at low gas flow rate (1 l/h). The numerical simulations were satisfactorily validated by experimental results. The comparison and the combination of the numerical and experimental results bring new insight into the flow pattern in a SMXTM static mixer
 
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Alternative Names
École doctorale 608

École doctorale Sciences et ingénierie des molécules, des produits, des procédés, et de l'énergie

École doctorale SIMPPé

ED 608

ED608

SIMPPé

Languages
French (14)

English (6)