Teses / dissertações sobre o tema "Réactions chimiques – Développement durable"
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Dias, Hugo. "Catalyseurs bioinspirés pour la valorisation du co2 en carbonates cycliques". Electronic Thesis or Diss., Lyon 1, 2024. http://www.theses.fr/2024LYO10192.
Texto completo da fonteThe CO2 valorisation is a strategy that could solve current issues. By using as a reagent this abundant molecule which is considered as an anthropogenic waste product, the development of sustainable syntheses of high added value products is becoming a key challenge for the chemical industry. The synthesis of cyclic carbonates is a typical example of a green reaction that converts CO2 into useful products for polymer and lithium battery industries. However, the CO2 cycloaddition to epoxides requires the use of selective catalysts to avoid the formation of undesirable polymers. Within living organisms, carbonic anhydrase has been widely studied and recognised for its reversible ability to rapidly convert CO2 into HCO3-. Nevertheless, the application of this metalloenzyme is prohibited for an industrial use due to its instability outside physiological conditions and its expensive cost. Inspired from this macromolecule whose active site is a zinc complex surrounded by L-histidine ligands, the aim of this thesis was to develop a selective catalytic system for the synthesis of cyclic carbonates under mild conditions. Catalytic evaluations of zinc salts and L-histidine derivatives were carried out and led to syntheses and exhaustive characterisations of a series of zinc complexes. Their stability and activity coupled with their selectivity towards cyclic carbonates prompted further researches into the grafting of those complexes onto supports. Functionalised mesoporous silicas were prepared and their catalytic activity tested, enabling those selective bioinspired catalysts to be recycled
Hany, Cindy. "Développement de méthodes thermiques pour la caractérisation de réactions chimiques en microfluidique". Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13936/document.
Texto completo da fonteThis work deals with the development of new measurement methods in order to characterize high exothermic chemical reactions in safe conditions. Thus, we combine thermal analysis with microfluidic technology. The use of microfluidics allows to manipulate a very small amount of product safely. First, we have developed a microcalorimeter to measure the global heat flux produced in co-flow or droplet-flow configurations. Several parameters can be determined: reaction and mixing enthalpy, concentrations by calorimetric titration and kinetics. The second method uses an InfraRed camera to measure the temperature field of the isoperibolic millireactor. Then, the local evolution of the reaction is estimated by thermal processing. From such inverse methods, the thermokinetic parameters can be determined
Quinton, Julia. "Développement et utilisation de dosages immunométriques pour la recherche de nouvelles réactions chimiques". Paris 11, 2010. http://www.theses.fr/2010PA112218.
Texto completo da fonteThe main goal of this project is the discovery of new ligation reactions by sandwich immunoassays. These sandwich test are usually used for the detection of macromolecules (proteins, virus or bacteria) for applications in diagnostic and they are poorly described for the detection of small compounds. Firstly, the development of the "sandwich test" has been carried out by evaluating the minimum size of the compounds which could be detected through the simultaneous binding oftwo antibodies. This study showed that a ternary complex could be formed even if the spacer separating two epitopes is constituted by only 5 carbon atoms. The screening by "sandwich test" has been first validated on known reactions: the Huisgen cycloaddition and Sonogashira reactions. Secondly, the screening by "sandwich test" has been realised in order to find new reactions. 2688 reactions have been realised on 96 well plates in different experimental conditions and then screened by "sandwich test". 67 hits have been observed and resulted from the formation of cross coupled products. However, among these 67 hits, 13 products resulted from known reaction and 54 hits resulted from new ones. Only 2 reactions have been optimised and reproduced at bigger scale. This screening led to the discovery of a new desulfuration reaction catalysed by copper that allowed the straighfoward formation of iso-urea in presence of phenols. This reaction was very efficient in an intramolecular way and led to the formation of benzoxazoles from aminophenols. Then, this screening permitted the disco very of a second new reaction: an innovative reaction of cyclisation in the presence of N-hydroxythiourea, alcynes and copper salts
Koubachi, Jamal. "Développement et application des réactions d'arylations et d'alcénylations directes pallado-catalysées pour la synthèse d'imidazo[1,2-a]pyridines diversement substituées". Orléans, 2008. http://www.theses.fr/2008ORLE2021.
Texto completo da fonteBui, The Thuong Mathieu. "Développement d'une méthode d'analyse des milieux réactionnels par spectrométrie de masse APPI". Strasbourg, 2011. http://www.theses.fr/2011STRA6242.
Texto completo da fonteThe aim of the project is to set up a universal method, easy to implement, that gives a rapid and precise information on the composition of the reaction mixture (identification and quantification of compounds of interest) and to evaluate the scope of the method. The principle of this method, [TMOA-APPI-MS], relies on the labeling of a compound of interest by an organic molecule that is chemically inert and owns selective ionization by APPI. In this method, the label (trimethoxybenzene) is selectively ionized and only the labeled molecules are detected. The label decreases the influence of the other functions on the molecule or in the reaction mixture and allows a standardization of the analysis conditions. The method was first compared with classical techniques (NMR, GC, HPLC) in a carbonylative Sonogashira coupling. The study of more complex reaction mixture with amines was then undertaken. This study enabled the optimization of reaction conditions for the synthesis of heterocycles starting from a labeled ynone. A reaction of deethylation of triethylamine catalyzed by platinum was discovered by the method [TMOA-APPI-MS]. A study to validate the discovery of "new reactions" was then undertaken. Known and new reaction conditions were applied to labeled model substrates with alkyne or diyne functions. The reactions were analyzed by the method [TMOA-APPI-MS], in order to ensure its ability to detect new transformations. This systematic screening showed that silver selectively catalyzes the hydration of terminal alkynes
Maximin, Céline. "Stratégies d'innovation, capital humain et développement durable : Le cas des entreprises du secteur chimique en France". Paris 1, 2008. http://www.theses.fr/2008PA010044.
Texto completo da fonteRoubinet, Benoît. "Développement de nouveaux outils chimiques pour la conception d'un système de détection fluorogénique des réactions catalysées par les polymérases". Rouen, 2015. http://www.theses.fr/2015ROUES012.
Texto completo da fonteDuring the past decade, considerable research efforts have been devoted to the field of bioanalysis of nucleic acids, and significant achievements have been done, particularly through the development of new methods for high-throughput DNA sequencing (HTS). This was made possible thanks to advances in optical detection methods, in particular fluorescence techniques which have some advantages including high sensitivity and ease of implementation. It is in this context that this current project takes place, whose ultimate and ambitious goal is the development of a novel fluorogenic system for real-time monitoring of DNA replication process. The main objective of this Ph. D. Thesis is to obtain a first proof-of-concept through the synthesis of a novel class of thionucleotides that only differ from the natural nucleotides by the replacement of the bridging-oxygen between phosphorus atoms Pα and Pβ by a sulfur atom ("P-S-P" moiety), to increase the nucleophilic character of the anion, released upon action of DNA polymerase (thiopyrophosphate (ThioPPi) instead of pyrophosphate). Subsequent reaction of ThioPPi with thiol-reactive latent fluorophores will enable detection of this enzymatic event. The first part of this work was devoted to the rational design and structural optimization of this pro-fluorescent system. Novel water-soluble phenol-based fluorophores derived from 7- hydroxycoumarin scaffold have been synthesized and the evaluation of their photophysical properties has been done. Their subsequent conversion to thiol-sensitive fluorogenic probes (reactive toward both ThioPPi and its decomposition product thiophosphate anion) through the chemical modification of their hydroxyl group was achieved. This comprehensive study has enabled us to select some latent fluorophores exhibiting both biocompatibility and high reactivity toward thiols, suitable for targeted application. The second part was devoted to the synthesis of original thionucleotides by exploring unusual synthetic strategies leading to "P-S-P" moiety; some valuable/interesting results were obtained. The third part aimed at highlighting some of the synthesized molecules in bioanalytical experiments
Noël, Maxence. "Etude des relations structure-fonction des sialyltransférases humaines : développement de nouveaux outils". Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1S109/document.
Texto completo da fonteSialylation is a major modification of glycoproteins and glycolipids and is involved in cellular and molecular processes. The sialylation reaction is catalyzed by sialyltransferases, a group of golgian glycosyltransferases using an activated sugar donor in the form of CMP-sialic acid. These enzymes, 20 in humans, have redundant enzymatic activities and have a very fine specificity towards the accepting substrate. Their deregulation leads to altered sialylation profiles in pathological situations but little is known about their functional organization in the cell. Techniques for studying the sialylation reaction and sialoglycoconjugates are numerous but rarely present the possibility of selectively monitoring O- or N-glycans. In this context, I have produced different recombinant and soluble sialyltransferases and developed new strategies for studying these enzymatic activities in in vitro and in cellulo assays based on the use of a non-natural sialic acid: CMP-SiaNAl. This unnatural sialic acid derivative carrying an N-alkyne group serves as a chemical reporter for the detection and visualization of sialoglycoconjugates. After having shown that this substrate is used with the same affinity as the natural substrate, I developed new tools allowing the study of sialyltransferases. In addition, I was able to provide elements of understanding as to the molecular and functional evolution of this ST6GAL1 in vertebrates, implying an evolution of its enzymatic activity in mammals
Bur, Nicolas. "Etude des caractéristiques physico-chimiques de nouveaux bétons éco-respectueux pour leur résistance à l'environnement dans le cadre du développement durable". Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00804542.
Texto completo da fontePascual, Espuny Céline. "Le développement durable : promesse d’un changement paradigmatique ? : étude d’un processus discursif et négocié : un exemple : Reach* (* règlement européen sur les substances chimiques)". Paris 4, 2007. https://hal-amu.archives-ouvertes.fr/tel-01896585.
Texto completo da fonteThis thesis questions the notion of sustainable development, it considers the way the idea came into being, how it has been transmitted, diffused, and how it has evolved. The viewpoint that has been retained is based on the fact that sustainable development contains a paradigmatical potential, and that it proposes logical and cognitive ruptures. In that perspective, considering sustainable development as a paradigma comes under a central question, that of the question of norms in the process of changing. The construction of these norms can be envisaged in their diffusion in a public sphere. It is a two-step study : first, in the analysis of texts we consider to be “founders”, from which sustainable development emerges and which determine a field of action whilst allowing interpretation. Then times of controversy, of publicised debates take place, and constitute a second period of normalisation, in a more open space. By the analysing and cross-checking of eight years’ worth of articles and press releases from Reach, (European regulation on the Registration, Evaluation and Authorisation of Chemicals, which was adopted in decembre 2006), we can observe the discursive and negociated process of the normalisation of sustainable development
Lomate, Samadhan. "Développement de catalyseurs performants pour l’oxydation sélective d’éthanol en oxyde d’éthylène". Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10071.
Texto completo da fonteThis thesis deals with the development of heterogeneous catalysts for the direct conversion of ethanol into ethylene oxide. Various catalysts were prepared using different techniques including impregnation and co-precipitation methods. These catalysts were characterized in order to determine their structural, textural and chemical properties as well as their elemental compositions using XRD, XPS, XRF, SEM, TEM and TPR. The performance of the catalysts in the direct conversion of ethanol to ethylene oxide was determined in a vapor phase down-flow fixed-bed reactor at atmospheric pressure. Furthermore, the impact of reaction conditions (temperature, GHSV, ethanol/oxygen ratio) was studied. Thus, it was notably found that the reaction conditions significantly affected the catalytic performance, which was ascribed to the fine-tuning of the redox cycle enabling the stabilization of the catalysts oxidation state. Finally the mechanistic aspects of the reaction were studied notably with the focus to identify the reaction pathways and the intermediates
Baumgarten, Guilherme. "Développement et caractérisation d’une sonde RMN portable appliquée au suivi de la qualité de l’eau et à l’étude de la cinétique des réactions chimiques". Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAD014.
Texto completo da fonteNuclear Magnetic Reaction (NMR) spectroscopy is a widely employed technique in the detection and quantification of chemical compounds, with a wide range of applications. In this manuscript, the focus is put on two of them: the detection of pollutants in drinking water and the monitoring of chemical reactions. While laboratory NMR equipment presents highly reliable analysis results, portable miniaturized NMR is an evolving research field with multiple technological and application-related challenges. Such emerging devices present however a clear advantage when compared to the classic, stablished ones: it can be used in the field, therefore saving time and limiting staff and consumables costs. In order to design NMR spectrometers to attain the desired portability and miniaturization, one has to compromise, however being able to understand what is at stake, so that the final product still meets the demands. For that, we propose a complete NMR simulation toolchain capable of generating diverse outcomes corresponding to a real NMR spectrometer. Furthermore, we develop a proof of concept for an electronic control and acquisition unit based on commercial-off-the-shelf components and validate it on a portable NMR spectrometer prototype. Finally, we use this prototype to assess the potential of portable miniaturized NMR for the targeted applications cited above. This study allowed us to identify the limits of our current prototypical device and to provide directions for its further improvement
De, Robillard Guillaume. "Synthèse et réactivité chimiques et électrochimiques de dérivés d'imidazoliums : vers des procédés éco-responsables". Thesis, Dijon, 2015. http://www.theses.fr/2015DIJOS026/document.
Texto completo da fonteThis work deals with the use of electrochemistry as a tool for alternative synthesis of new azolium-based molecules.A new electrosynthesis method was developed for the synthesis of imidazolium carboxylates (masked carbenes) leading to a wide library of compounds. This approach was compared to already reported chemical syntheses. In the current context of sustainable development, bio based products have been synthesized and optimization of the process was achieved in order to reduce waste and energy consumption.The key role of the hydrogenoxalate anion was demonstrated in the synthesis of ionic liquids and/or imidazolium salts. Some of them were employed as recyclable catalysts for Fischer esterification.The direct electrochemical reduction of various azoliums was also studied. The coupling of two electrogenerated neutral radicals leads to the corresponding σ-dimers. The oxidation of this species gives back the starting azolium proving the “reversibility” of the reaction, paving the way for new molecular switches.Azolium containing pyrene moiety was also electrosynthesized. Thus, electrochemical oxidation of pyrene in presence of different nitrogen nucleophiles leads to azolium pyrenes. This process was optimized in order to reduce waste and simplify the experimental setup. Some products have shown antimicrobial activities
Foret, Sylvain. "Etude d'un nouveau procédé de fractionnement des co-produits de fabrication de jambon sec et des propriétés physico-chimiques et fonctionnelles des extraits et raffinats". Thesis, Toulouse, INPT, 2011. http://www.theses.fr/2011INPT0075/document.
Texto completo da fonteThe ham production by-product comes from the deboning of dressed, salted, dried and refined pork leg. It consists of more than 85% of bone and associated tissues (cartilage, ligaments, tendons). Hammer mill crushing allows homogenizing the by-product into pieces smaller than 8 cm (> 90% between 40 and 80 mm).Dry matter chemical composition of the blend; (77 ± 3% DM) is 33 ± 5% protein (89% collagen, 14% of watersoluble proteins, 6% free amino acid), 31 ± 3% lipids (triglycerides: 70% diglycerides: 3.5%; free fatty acids: 11%; saturated / unsaturated: 0.87; 24% C16: 0; 13% C18: 0; 2% C16: 1; 38% C18: 1; 4% C18: 2) and 26 ± 4% mineral matter (calcium phosphate 88%, 9% NaCl). Lipids and proteins aqueous extraction of the by-product is studied in an agitated contactor reactor. The solid raffinate was separated by hot filtration to an aggregate and the fat is separated by cold decantation.The study of the influence of main factors of the liquid / solid extraction (contact time: 30 to 90 min, temperature: 40 to 90 °C; ratio water / by-product: 4 to 10) through the implementation of an experimental design, highlights the effects of proteins dissolution and coagulation on lipid output and decantation as fat matter.By pilot scale implementation (64 kg of crushed by-product of dry-cured ham, 207 kg of water, 30 min at 90 ° C in agitated contactor), the aqueous fractionation process leads, by centrifugal filtration and drying, to a stable aggregate (yield: 59%; mineral matter: 41%; protein 43%; lipids: 16%), source of calcium phosphate (95% of the mineral) and gelatin or bone glue (88% collagenous protein).The decanted fat fraction (yield: 24%; lipids: 93%; triglycerides: 75%; diglycerides: 4% free fatty acids: 7%; saturated / unsaturated: 0.82%; 37% C16: 0; 15% C18: 0; 2% C16: 1; 44% C18: 1; 8% C18: 2) has the same physicochemical characteristics as lard, with an odor similar to that of dry-cured ham (19 identified aromatic VOC part of ham main flavors). The solubilized protein fraction, obtained as a lyophilized extract after concentration of the aqueous phase (yield: 8%; protein: 52% with 29% of free amino acids; mineral matter: 29%, with 90% NaCl, lipids: 3%), also contains sulfated glycosaminoglycans (GAGs: 3.4%). These composition characteristics, associated with its thickening and gelling properties, adhesive and stabilizing for emulsion, transforms this minor fraction of the aqueous fractionation process of the dry-cured ham byproduct, in an high added value multiple applications extract (source of peptones for culture for fungi and yeasts, a natural and binding adhesive, ingredient for food nutraceutic and cosmetic formulation)
Lizzul-Jurse, Antoine. "Développement de nouvelles réactions de click in situ appliquées à la synthése d'inhibiteurs de la β-sécrétase". Thesis, Normandie, 2017. http://www.theses.fr/2017NORMR020.
Texto completo da fonteThe kinetic target-guided synthesis (KTGS), is an underexplored alternative approach to combinatorial chemistry, in which the biological target is able to assemble its own inhibitors from a pool of fragments. Thus, the first part of this thesis aimed at extending the scope of the reactions available for the KTGS, by investigating the aldolisation and amidation reaction, using the β-secretase (BACE-1) as biological target, which is an enzyme narrowly involved in the Alzheimer's disease. The second part of this thesis was dedicated to the synthesis of bioconjagatable fluorophores containing a phosphonium group as mass tag associated to a coumarin core. Both generations presented in this manuscript allowed us, among other things, to synthesize a FRET probe that proved suitable for the determination of BACE-1 enzymatic activity. The utility of such a fluorogenic tool could be leveraged to facilitate the analysis of crude mixtures obtained during KTGS experiments, and lessen the amount of enzyme required in these experiments. Finally, in the last part of this thesis, we describe the development of two new bioorthogonal reactions allowing the selective labeling of molecules containing an aldehyde moiety : 1) a three component reaction involving a condensation/Mannich/lactamisation procedure, between an amine, an aldehyde and an enol partner; 2) a Wittig ligation between an aldehyde and a phosphonium bearing an active methylene
Gasc, Julien. "Développement de mesures cinétiques, électriques et acoustiques pour l'étude de réactions minéralogiques sous pression et température : applications à la micro-sismicite induite et au rôle de l'eau sur les cinétiques chimiques". Paris 11, 2010. http://www.theses.fr/2010PA112350.
Texto completo da fonteMetamorphic reactions are solid state transformations which affect rocks experiencing changing pressure and temperature conditions. First, we have used in situ electrical conductivity measurements as well as X-ray diffraction techniques to study the effect of water content on transport properties at the grain boundaries during high pressure experiments (1,8 GPa). We showed that the diffusivity is enhanced by many orders of magnitude by the addition of only 1 wt. % of water within the samples. Then we propose an Arrhenius law that allows calculating a diffusion coefficient as a function of both temperature and water activity. These results may have strong implications concerning geodynamical and petrological modelling of high pressure–low temperature metamorphic reactions. Secondly, we have studied many metamorphic reactions (including serpentinite dehydration) by coupling in situ X-ray diffraction and acoustic emissions monitoring techniques during multi-anvil experiments. The recording of thousands of acoustic emissions during the cold compression stage of our experiments allowed us to evidence brittle fracturing of the samples. On the other hand, no acoustic emissions were collected during dehydration reactions as proposed by former studies. We show here that the long viewed coupling between dehydration reactions, deformation and seismicity are not as straightforward as one could expect and require high differential stress levels
Boudjehem, Mohamed Redhouane. "Développement de la tomographie spectro-ptychographique aux rayons-X pour la caractérisation hyperspectrale 3D de catalyseurs techniques". Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALY021.
Texto completo da fonteTechnical catalysts accelerate chemical reactions in the petroleum industry, transforming crude oil into finished products such as gasoline, diesel, and jet fuel. Understanding the relationships between the structure, properties, and functions of catalysts is crucial for reducing pollution caused by chemical reactions during catalysis. This thesis aims to develop a 3D spectral nano-imaging method to characterize the microstructure of technical catalysts at the nanoscale. The technique combines X-ray tomography and ptychography with X-ray absorption spectroscopy. It will allow us to determine the location and chemical state of metals that promote or poison catalysis. The main challenge lies in reducing the data acquisition time, currently 24 hours for 2 energy points. The main contribution of the thesis will be to develop new methods for faster acquisition without loss of information. This will improve the understanding of the structure-performance relationship of catalysts, leading to more efficient and economical developments
Bruniaux, Sophie. "Nouveaux hydrotropes biosourcés : conception, synthèse et propriétés physico-chimiques en milieu hautement salin". Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2378.
Texto completo da fonteHistorically, chemical industry was based on fossil ressources, but alternative processes have been developed since the nineteens to be green and to answer to the environmental eco-responsibility questions. In this context, a collaboration work between three public laboratories and the SAS PIVERT emerged to find new biosourced hydrotropes starting from various polyols – such as glycerol, main byproduct of the fuel production – and resistant to high saline conditions. A specific design was defined by our physico-chemical partner for the synthesis of hydrotropes. Differents approaches were used to obtain these compounds, such as a new method of methylation using sub/supercritical methanol with a phase of optimization, and another about the scope of the reaction that reduced the reaction steps. The transposition of the reductive alkylation of various alcohols was also realized – using a heterogeneous catalysis – with the obtention of various ethers, in continuous flow conditions, by the intermediate of the use of the HCube Pro from ThalesNano
Olivon, Kevin. "Procédés catalytiques et outils millifluidiques : applications aux réactions de Friedel-Crafts et d'oxydation". Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0143.
Texto completo da fonteThe search for new methods for the acquisition of physical and chemical reactions by limiting the effect on humans is of great importance for modern chemistry. The use of new miniaturized tools can limit the quantities of chemicals used while increasing research productivity. Indeed, the study of the various parameters monitored simultaneously increases the number of experimentsfor a given time. Nevertheless, this step must be performed after prior determination ofthe key parameters of the reaction by the use of high flow tools such as robotics. These tools are used for optimization and the search for new synthetic pathway of a reaction of industrial interest. In addition, to meet the interests of heterogeneous catalysis in industry for easier separation and recycling of these catalysts, we have developed two miniaturized tools. These allow the study and data acquisition of chemical reactions catalyzed by solid. Development was registeredin two stages : a physical characterization tools and the study of an industrial model reaction, the acylation of anisole with zeolite catalysts
Toundou, Outéndé. "Evaluation des caractéristiques chimiques et agronomiques de cinq composts de déchets et étude de leurs effets sur les propriétés chimiques du sol, la physiologie et le rendement du maïs ( Zea mays L. Var. Ikenne) et de la tomate ( Lycop ersicum esculentum L. Var. Tropimech) sous deux régimes hydriques au Togo". Thesis, Limoges, 2016. http://www.theses.fr/2016LIMO0020/document.
Texto completo da fonteSoil nutrient depletion and water deficit as a result of seasons’ disruption are major factors adversely affecting crop yields in West Africa. To remedy this, the amendment of compost-based soil is often considered. In this study, Five composts were elaborated using household waste and agri-food waste, manure and phosphate: composts C1 (household waste + agri-food waste), C2 (C1 + manure), C3 (C1 + natural phosphate), C4 (C1 + manure + natural phosphate) and C5 (agri-food waste). These composts were first characterized and their effects on an acidic soil and on two crops (corn and tomato) were then investigated in greenhouse and field under two water regimes in the goal to identify the best's ones in improving resistance of the two crops to watering reducing, applied prior flowering. The results showed for C4 and C5 high contents of phosphorus, about 1.62% compared to 0.09% for the C1 compost. Composts C3 and C4 showed the highest levels of calcium, about 3.9% compared to 1.2% for the C1 compost while composts C4 and C1 were more hydrophobic than all other composts. Plants of corn grown under constant irrigation on soil amended with compost C4 and C5 in greenhouse showed high nitrogen and potassium contents, respectively 2.55% and 6.69% compared to 1.33% and 3.97 % of the control plants and those grown on synthetic fertilizers. Under reduced watering, we recorded higher potassium and calcium contents in plants grown on all of the five composts compared to control plants. In field, under reduced watering, composts C4 and C5 were those leading corn plants to maintain physiological parameters levels (low cell membrane permeability and high total chlorophyll) compared to well –watered plants. We also recorded for both composts the same grain yields in plants submitted to two water regimes, respectively 5.52t/ha and 6.72t/ha for C4 and C5 in well-watered plants and 5.65t/ha and 5.09t/ha for C4 and C5 in plants grown under low water regime. In tomato, an increased weight of fruit per plant was recorded in C3 compost plants under reduced-watering compared to those well-watered (95.93g compared to 44.29g) while in the same conditions, the compost C5 was the best for the number of fruits per plant (7.39 against 4.26). These data indicated that the three composts C3, C4 and C5 were the most efficient in this study and may be retained in adaptation programs of two crops to climate change for a sustainable development
Duncianu, Marius. "Réacteur à écoulement pour l’étude de la formation des aérosols organiques secondaires par ozonolyse de composés organiques volatils : développement analytique, validation cinétique et ozonolyse d’un composé biogénique". Electronic Thesis or Diss., Lille 1, 2012. http://www.theses.fr/2012LIL10039.
Texto completo da fonteA steady flow reactor equipped with a mobile injection head was developed at the Chemistry and Environment Department, Ecole des Mines de Douai, to better understand the formation processes of secondary organic aerosols (SOA) following the gas phase oxidation of certain species particularly reactive and/or abundant in the atmosphere. In contrast to atmospheric simulation chambers the flow reactor allows to observe in stationary conditions the product formation in the early stages of the reaction at ambient pressure and temperature.The foremost part of this work was to characterize the reactor flow, and to develop and optimize the methods used for the gas phase analysis. In a second stage a kinetic study of the ozonolysis of methylated pentenes and α-pinene was performed to validate the system. The rate coefficients were determined in pseudo first order conditions with excess alkene and showed a good agreement with literature values. The expected oxidation pathways were identified and quantified for one alkene (in good agreement with the only study available), and a nonoxidized intermediate coming from the rearrangement of a Criegee biradical, has been found for short reaction times. Finally, the SOA formation from α-pinene ozonolysis was investigated with simultaneous characterization of the gas phase concentrations of reactants and products (by ozone analyzer and TD/GC/FID-MS), of the particle size distribution (by SMPS and HR-ToF-AMS), and of the average chemical composition of particles (HR-ToF-AMS)
Kadi, Mohamed El Amine. "Contribution à l'étude de l'influence des biocarburants et de leurs propriétés sur le fonctionnement des moteurs à combustion interne". Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2020. http://www.theses.fr/2020IMTA0207.
Texto completo da fonteGlobal warming, mainly due to greenhouse gases, and the increasing of global demand for fossil fuels and their rapid depletion, represent strong environmental and economic challenges, which have prompted the global community to turn to alternative and renewable energy. This thesis falls within this perspective of developing renewable energies. The research work can be summed up in two main areas,where the first includes the development of the process of continuous biodiesel production with different raw materials through two reactions (transesterification and esterification). This axis consists of a simulation under ANSYS Fluent of the flow of fluids inside a chaotic mixer, a synthesis and purification of biodiesel, a kinetic study of the biodiesel production system, followed by an investigation on the effects of operating conditions on biodiesel’s yield and properties. The results obtained showed the effectiveness of this process in intensifying the continuous production of biodiesel. The second axis was devoted to the study of the effect of the physicochemical properties of biodiesels on the internal combustion engine operation. In this part, several biodiesels having a wide range of physicochemical characteristics were used in a direct injection (DI) and naturally aspirated diesel engine, with a rated electric power of 30.4 kW at 1500 rpm. Engine performance (specific consumption, efficiency) and pollutant emissions (unburnt hydrocarbons, NOx, CO2, CO, PM) were studied for the various biodiesels, used alone or as a mixture. The results showed a small deviation between the various biodiesels tested in the engine with the exception of HC and particulate emissions
Duncianu, Marius. "Réacteur à écoulement pour l’étude de la formation des aérosols organiques secondaires par ozonolyse de composés organiques volatils : développement analytique, validation cinétique et ozonolyse d’un composé biogénique". Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10039/document.
Texto completo da fonteA steady flow reactor equipped with a mobile injection head was developed at the Chemistry and Environment Department, Ecole des Mines de Douai, to better understand the formation processes of secondary organic aerosols (SOA) following the gas phase oxidation of certain species particularly reactive and/or abundant in the atmosphere. In contrast to atmospheric simulation chambers the flow reactor allows to observe in stationary conditions the product formation in the early stages of the reaction at ambient pressure and temperature.The foremost part of this work was to characterize the reactor flow, and to develop and optimize the methods used for the gas phase analysis. In a second stage a kinetic study of the ozonolysis of methylated pentenes and α-pinene was performed to validate the system. The rate coefficients were determined in pseudo first order conditions with excess alkene and showed a good agreement with literature values. The expected oxidation pathways were identified and quantified for one alkene (in good agreement with the only study available), and a nonoxidized intermediate coming from the rearrangement of a Criegee biradical, has been found for short reaction times. Finally, the SOA formation from α-pinene ozonolysis was investigated with simultaneous characterization of the gas phase concentrations of reactants and products (by ozone analyzer and TD/GC/FID-MS), of the particle size distribution (by SMPS and HR-ToF-AMS), and of the average chemical composition of particles (HR-ToF-AMS)
Mangin, Floriane. "Synthèses de nouveaux tensioactifs éco-compatibles : étude de synthèses catalytiques et radicalaires en milieu micellaire". Thesis, Compiègne, 2015. http://www.theses.fr/2015COMP2224/document.
Texto completo da fonteBased on concepts of sustainable development and green chemistry, one of the alternatives envisioned by chemists is to substitute organic solvents, which can be dangerous and toxic, for greener solvents. Water is the best candidate for this substitution because it is thesafest and cheapest solvent in our countries : this solvent is non-toxic, non-flammable and inexplosive. In order to overcome the low solubility of most of organic compounds in water, surfactants can be used to improve the reaction yields. Media thus obtained are difficult to recycle because they require high dilution in order to break aggregates and recover products. Therefore, using photo-switchable surfactants is a good alternative because they can organize/disorganize by light irradiation. Organic compounds could be recovered after reactions and the recyclability of the medium can be improved. For this purpose, we synthesized three surfactants having an azobenzene moiety (anionic,cationic, nonionic), to test them in micellar catalysis. Some of these surfactants, after determining their physicochemical properties (CMCs and UV-visible spectra) were studied in a pallado-catalyzed reaction, the allylic substitution of Tsuji-Trost. We have successfully demonstrated the value of using a photo-switchable surfactant compared to commercialones in terms of yields and recyclability. In other hand, Barton decarboxylation, described for the first time in 1983, permits the formation of alkanes from carboxylic acids, using tin derivatives as hydrogen donors. Since then, this reaction has always been used as a key step in total synthesis of natural compounds in organic solvents. In addition, historically, this reaction was carried out by conventional activation (heat or ultraviolet light). Therefore, we decided to study this radical decarboxylation in water, in the presence of surfactants and using unconventional activation modes : microwave and ultrasound. Moreover, instead of tin, we preferred the use of N-phenylmaleimide, already known and studied as a radical trap, to obtain maleimides substituted by carbon chains. Yields obtained in micellar media were found tobe at least as good as in organic solvents
Hernandez-Shek, Manuel Alejandro. "Développement et validation de méthodologies et d’outils opérationnels de caractérisation rhéologique de biomasses appliqués au procédé de méthanisation en voie solide, et conception de réacteurs de 0,5 m3". Thesis, Compiègne, 2020. http://www.theses.fr/2020COMP2579.
Texto completo da fonteContinuous dry anaerobic digestion (D-AD) in plug flow reactor (PFR) is a promising process that is growing interest in the treatment and energy recovery of agricultural waste. The biomethane production provides an additional income to farmers and a source of natural fertilizer, additionally, this process is in line with UNESCO's sustainable development objectives through the production of renewable energy, employment creation and the fight against climate change. Despite the potential of this process in the current energy context, scientific and technological obstacles need to be solved to better understand and control the phenomena involved, to increase the profitability of the installations and to make this technology more accessible to small and medium-sized farmers. The objective of this work is to provide solutions to the problems related to the development of continuous D-AD in PFR, especially for the Easymetha process. First, the objective was to develop and validate rheological measurement tools and methods adapted to D-AD process at pilot and industrial scales. Three alternative rheological analysis methods were developed to measure the rheological properties (yield stress, viscosity, cohesion and angle of friction) of the biomass as well as its flowability. A Slump Test, a consistometer and a shear box of large volumes (>10 L) allowed to characterize the rheological properties of artificial mixtures of raw and crushed straw manure. Then, the second objective focused on the development and application of a Water Retention Curve (WRC) method for the determination of the evolution of the porosity distribution of manure treated in batch reactors. Then, the objective was to establish the effect of immersion, the absence of recirculation of the liquid phase and the height of the solid mass on the degradation of the material and its physical and rheological properties as a function of height, two digestion columns with a height of 2.5 m and a total volume of 440 L were constructed. Two levels of immersion were tested to demonstrate the low need for liquid recirculation once the solid mass is immersed in the liquid fraction. The importance of this parameter for continuous D-AD systems fed with raw substrates is discussed. Immersion can promote the formation of hydraulic seals at the reactor inlet and outlet and the horizontal displacement of the material. These experiments have provided a solid basis for the next objective, which is to design and operate a continuous D-AD pilot PFR with a design as close as possible to the Easymetha process. The development of a new D-AD system at the pilot scale consisted of a 500 L PFR, a large volume where the material advances over a length of 2 m. This pilot has been operated continuously for 100 days, its operation has shown the aptitude and resilience of this system for the valorization of raw straw cattle-manure. In addition, a tool for simulation and prediction of methane flow behavior from batch data was created and validated with the experimental results of the pilot. Finally, the evolution of the rheological properties of the manure in continuous and batch reactors was measured using the previously developed and calibrated tools. This thesis is based on several multi-scale and complementary experiments allowing a better understanding and optimization of the process of continuous dry-process anaerobic digestion of raw agricultural by-products
Wang, Yantao. "Synthesis and conversion of furfural-batch versus continuous flow". Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2474/document.
Texto completo da fonteFurfural, which has been identified as one of top 30 bio-based chemicals, is an important green platform molecule, The aim of this PhD work is to realize the synthesis and conversion of furfural in batch and continuous flow. Here, we developed sorne greener methods for furfural synthesis, and valorized furfural into high value-added products, such as 2-furonitrile, furfuryl alcohol etc. Several keys issues were identified in order to design processes greener than the current ones. ln detail, experiments for furfural synthesis were performed in water or in water and organic solvent when co-solvents (green or eco-friendly) are necessary. Microwave irradiation has been chosen as the heating method to accelerate the dehydration process, and microwave continuous flow reactor was also applied to improve furfural productivity. When starting from furfural to produce high value-added chemicals, efficient flow reactors, suc as Pheonix, H-cube Pro as well as microwave continuous flow With micro-reactor, were also identified as interesting alternatives to improve the productivities of target compounds. As a result, some promising results were obtained in the viewpoint of industry
Bousquières, Josselin. "Impact de la composition et des procédés sur la réactivité d’un produit modèle alvéolé de type cake". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLA004/document.
Texto completo da fonteIn the food industry and notably in the field of cereal products, the type of ingredients used and their associated processes have several effects on the structure of the products and on the chemical reactions occurring during the manufacturing process. These reactions could have positive impacts (aroma, color) as well as negative outcomes (formation of potentially toxic compounds). Although being thoroughly studied in model systems, a better understanding of reactions in more realistic conditions would allow to improve the quality of the products. The aim of this work was to enable the study of chemical reactions occurring in a simplified solid system where the composition and structure were controlled while remaining representative regarding the conditions of the processes and the structure of the real product. Sponge cake was chosen as the product of reference.The first step consisted in developing a model product constituting a basis for studying the reactivity. In this regard, a study on new functionalities brought by each ingredient during each step of the manufacture process allowed to identify the cellulose derivatives as candidates to replace the reactive ingredients (eggs, sugar and wheat flour proteins). A multi-scale study allowed to better understand the impact of the main properties brought by the cellulose derivatives (viscosity at cold temperature, interface stabilization, gelation at high temperature) on the structure of the product. Finally, the model product was validated as a non-reactive media regarding the Maillard reaction and the caramelization.In a second step, reactive compounds (glucose and leucine) were placed in the model product and a kinetic monitoring on reaction markers was set up in the vapors and in the matrix during the baking. Thus, the addition of glucose and leucine in the model allowed to follow the formation of typical compounds coming from the Maillard reaction (Strecker’s aldehyde and pyrazines). These compounds did not developed when the model product was only enriched in glucose, whereas compounds generated by the caramelization reaction were identified. Moreover, changes in baking conditions (temperature, convection) allowed to emphasize the impact of heat transfer and drying on reaction pathways. These results pave the way of future kinetic studies, coupling systemic experiment and reaction modelling
Lu, Huiling. "Contribution à l'étude des relations structure-propriétés de molécules amphiphiles à tête sucre". Thesis, Compiègne, 2016. http://www.theses.fr/2016COMP2316/document.
Texto completo da fonteIn the context of sustainable development, the use of biodegradable and low toxic renewable resources is particularly important. ln particular, the literature shows that the bio-based amphiphilic molecules with a sugar head, or the glycolipids, are excellent substitutes of the petrochemical surfactants used massively in current formulations. To limit the experimental screening and to orient the choice of the syntheses of such molecules, a predictive approach based on the analysis of the molecular structure would make it possible to anticipate the properties of the amphiphilic molecules and to identify those with specific properties. The objective of this work is to develop a methodology through systematic syntheses, characterizations and analyses of glycolipids with gradual structural modifications, with the aim of identifying relevant links between heir amphiphilic properties and their structural characteristics. The obtained experimental data should make it possible to establish a comparable and reliable database, necessary for the development of predictive models. The results showed the significant influence of some structural parameters on the physico-chemical properties with clear trends, which are otherwise difficult to observe by using the non-comparable data collected from the literature. This work also demonstrated the importance of considering the behavior of amphiphilic molecules in water, through knowledge of their phase diagram, which allows for the unambiguous definition of certain properties like the CMC
Muralidhara, Anitha. "Physico-chemical safety issues pertaining to biosourced furanics valorization with a focus on humins as biomass resource". Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2508.
Texto completo da fonteThe present research work was integrated as part of the EU-funded project named HUGS (HUmins as Green and Sustainable precursors for eco-friendly building blocks and materials), involving 5 main partners (Institut national de l'environnement industriel et des risques - France, Avantium - the Netherlands, Institut de Chimie de Nice - France, Universidad De Cordoba- Spain and Leibniz - Institut Fur Katalyse Ev An Der Universitat Rostock- Germany). The project is essentially supported through five European Industrial Doctorate fellowships put in place when the HUGS-MSCA-ITN-2015 program was launched in 2016. The primary objective of the HUGS project was to explore several valorization pathways of so-called “humins” in order to add value and create better business cases. Humins (and similarly lignins) are the side products that may become low-cost feedstock resulting from a number of future biorefineries and sugar conversion processes. Humins are complex residues resulting from the Acid-Catalyzed Dehydration and condensation of sugars, having furan-rings in their polymeric structures. The work presented in this specific part of the HUGS project is essentially focusing on safety-related topics of all components and subsequent applications related to sugar dehydration technology. Priority actions were devoted to a first insight on the characterization of physicochemical safety profiles of the side-product humins and main (parent) furanic products. Some members of this large family of compounds (e.g. RMF and FDCA) have high volume potential which results in opening new doors towards the development of furanbased building blocks and a bio-based economy. Humins are residues or side products which can be burnt for energy. However, its safe and sustainable use in high-value applications could also become a key milestone in the so-called circular economy. In practice, the work has been developed in two main locations: primarily at the INERIS lab, located in Verneuil-en-Halatte and at Avantium, located in Amsterdam. Nearly all experimental research after the production of the components at Avantium was performed at INERIS. This involved the evaluation of physicochemical hazards of both humins (crude industrial humins and humin foams obtained by thermal curing) and a series of furanic compounds. Avantium is involved in the commercialization of humins, furanics and furanic polymers/materials as novel chemicals and materials. The work has encompassed: An extensive bibliographical review of humins, furanics, and their related products (polymers, composites) resulted in the following main conclusions o A lack of physicochemical safety-oriented studies for many furanic compounds and for humins was observed as these products are still in the early stage of development and only a few may be commercialized in the next 5 years.o Despite the limited availability of safety-related data, more studies on toxicity aspects have been conducted for a selected number of furanics than physicochemical safety-related aspects. o A few furanic family members that have been evaluated as biofuel components were found to have given better emphasis on addressing some physicochemical safety attributes. o Every modification of the process for acid-catalyzed sugar dehydration (such as solvent, temperature, residence time and sugar concentration) will result in different humins, which would certainly demand further characterization and safety profiling of the resulting humins. • Analytical development integrating the first examination of flash point distribution versus the Net Heating Values, and analysis of total heats of combustion of furanic compounds. • Design and development of experimental plan addressing the safety-related key parameters such as thermal stability, self-heating risks, fire-risk-assessment and flammability limits depending on the need for specific tests and availability of the test samples