Tesi sul tema "Pyrolite"
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Gay, Jeffrey. "Microstructures and anisotropy of pyrolite in the Earth’s lower mantle : insights from high pressure/temperature deformation and phase transformation experiments". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR043.
Microstructures in mantle rocks impact the way seismic waves travel through the Earth and are dependent on the pressure, temperature, and deformation applied to the rock. At approximately 660 km depth, an increase in seismic wave velocities mark a distinct boundary that separates the upper and lower mantle. Another boundary is found at approximately 2700 km depth and marks the beginning of the D" layer. Furthermore, observations of seismic anisotropy at these discontinuities have been made. These boundaries are largely believed to be related to phase transitions from ringwoodite [(Mg,Fe)2SiO4, space group Fd3m] to bridgmanite [(Mg,Fe)SiO3, space group Pbnm] to post-perovskite [(Mg,Fe)SiO3, space group Cmcm]. In order to make interpretations of these seismic observations, however, a sound understanding of what generates these microstructures is required.Here, we approach this problem through high pressure and high temperature experiments. We identify microstructures in polycrysalline mantle minerals resulting from in-situ transformation and deformation using radial and multigrain X-ray diffraction in the diamond anvil cell. In the first study we transform a bridgmanite analogue, NaCoF3, from a perovskite to post-perovskite structure. The following two studies investigate the transformation of an average mantle composition, pyrolite, at conditions relevant to the 660 km discontinuity and further deformation at pressures and temperatures corresponding to depths between 500 and 2400 km. In the final study, we test an aluminum rich 'pyrolite' composition (pyrolite minus olivine) in order to compare transformation and deformation microstructures to those observed in experiments on pure pyrolite.Results from radial diffraction experiments show the transformation from perovskite to post-perovskite in NaCoF3 are reconstructive in nature and for which we identify the orientation relationships. Major takeaways from the multigrain X-ray diffraction experiments are as follows: i) the decomposition from (ringwoodite + garnet) to (bridgmanite + davemaoite + ferropericlase) result in non-reconstructive 001 transformation textures in bridgmanite, 101 and 111 textures in davemaoite, and no preferred orientation in ferropericlase. ii) With further deformation, bridgmanite changes to 100 and 010 orientations with no change in either davemaoite or ferropericlase. iii) Textures in bridgmanite and davemaoite in pyrolite minus olivine are similar to those observed in our experiments on pure pyrolite.Finally, we use the results of these experiments to build a model for S and P-wave seismic anisotropy within a subducting slab and the surrounding mantle for multiple scenarios and compare our results to those of the literature. This interplay between experiments and seismic models are important in order to provide constraints on deformation, dynamics, and history of the Earth's interior
Krauss, Hans-Joachim. "Laserstrahlinduzierte Pyrolyse präkeramischer Polymere". Bamberg Meisenbach, 2006. http://d-nb.info/986458899/04.
Grioui, Najla. "Etude thermocinétique de la pyrolyse du bois : application à la pyrolyse du bois d'olivier". Nancy 1, 2006. http://www.theses.fr/2006NAN10111.
A theoretical and experimental study of thermo-kinetic of this wood particles pyrolysis has been developed. The thermophysical properties of the olive wood such as apparent density, porosity, permeability and thermal conductivity have been determined experimentally by different measurement methods. A kinetic measurements are carried out by thermogravimetric analysis in isothermal mode in the temperature range between 498 K and 648 K. The experimental curves obtained are interpreted by a kinetic model based on several decomposition stages. The kinetic model coupled with energy conservation equation leads to a non linear equations system which has been solved iteratively by using an implicit finite differences method. The obtained results are in good agreement with the available experimental data. The developed model is then applied to the pyrolysis of a cylindrical olive wood particle in different operating condition to simulate the effect of the reactor temperature and the particle size on the evolution of the temperature profile as well as the residual mass inside the thick particle
LE, BLEVEC JEAN MARC. "Ultra-pyrolyse du 1,2-dichloroethane". Compiègne, 1993. http://www.theses.fr/1993COMP585S.
Sorge, Cornelia. "Struktur der organischen Substanz in Böden und Partikelgrössenfraktionen : Pyrolyse-Gaschromatographie Massenspektrometrie und Pyrolyse-Feldionisation Massenspektrometrie /". Kiel : Institut für Pflanzenernährung und Bodenkunde, Universität Kiel, 1995. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=006976086&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Hadjoudj, Ahmed. "Variation des propriétés mécaniques d'élastomère de silicone durant la pyrolyse, modélisation des phénomènes transfert thermique et pyrolyse". Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37598144w.
Porath, Stefan. "Erzeugung von Chemierohstoffen aus Kukersit durch Pyrolyse". [S.l. : s.n.], 1999. http://www.sub.uni-hamburg.de/disse/23/inhalt.html.
Ayar, Ayhan. "Modellierung der Pyrolyse in einer Kohlenstaub-Druckfeuerung /". Aachen : Shaker, 2003. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=010387515&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Amahzoune, El Mustapha. "Pyrolyse-flash et gazéification d'anas de lin". Toulouse 3, 1987. http://www.theses.fr/1987TOU30296.
Energetic valorization of flas straw by a thermic way is studied. A thermal treatement , flash pyrolysis, is realised under various flow of carrier gas, the emperature range being 700-1000°C ; in some cases a catalyst is used. In the first part, temperature and carrier gas flow, nitrogen, influence on gas composition is studied : high temperature favours flax straw decomposition into light gases. At 1000°C, and 1 l/min nitrogen flow, the gas composition is : hydrogen 29 %, carbon monoxyde 42 %, carbon dioxyde 11 %, methane 15 %, other hydrocarbon, C2, 3 % ; carbon gasified ratio is about 80 %. In the second part, pyrolysis-gasification is studied with a carrier gas containing oxygen (until reaching the air composition) ; carbon gasified ratio reaches 98 % (1000°C). With 02 % = 5 the Gross CalorificValue, GCV, of the pyrolysis gas is 16200 KJ/Nm3 at 900°C. Several catalysts have been used ; a steel specifically treated is particularly active : methane production is increased, 24 % at 900°C, and so is the GCV of the gas, 19400KJ/Nm3. Flash -pyrolysis of flax straw results are similar with those of cellulose and wood finely divided. By the side, comparison between classic carbonisation and flash pyrolysis shows the great efficiency of the thermic flash
Kirsten, André. "Chemisches Recycling von PVC-haltigen gemischten Polyolefinabfällen sowie COC-Materialien durch Pyrolyse und Optimierung von Versuchsparametern mittels Pyrolyse-GC-MS". [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=96907364X.
Milhé, Mathieu. "Pyrolyse de plaquettes forestières en lit fixe continu". Perpignan, 2013. http://www.theses.fr/2013PERP1239.
Corrégé, Frédéric. "Pyrolyse des schistes bitumineux par ondes moyennes fréquences". Toulouse, INPT, 1991. http://www.theses.fr/1991INPT068H.
Donnot, André. "Craquage catalytique de goudron de pyrolyse du bois". Nancy 1, 1989. http://docnum.univ-lorraine.fr/public/SCD_T_1989_0298_DONNOT.pdf.
Reichel, Denise. "Rohstoffliche und verfahrenstechnische Einflussfaktoren der Pyrolyse biogener Rohstoffe". Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2017. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-228940.
The intention of this work was an intensive study of the influence of feedstock properties and process variables on biomass pyrolysis. Due to a lack in consistent data sets, including various feedstock parameters as well as product yields, compositions, and further properties, a laboratory fixed bed reactor was developed to overcome this problem. The pyrolysis reactor was used for experiments with 26 biogenous feedstock under variable process conditions. The reactor is suitable to assure nearly closed mass balances and a complete product recovery. Furthermore, it allows the minimization of secondary reactions. The used feedstock, which include cellulose, xylan, and lignin amongst others, represent a broad range of possible compositions and were intensively characterized by determination of fuel and physical properties as well as biopolymer composition. The varied process parameters are: temperature between 200 and 700 °C, heating rate in the range of 5 to 100 K/min, solid residence time from 0 to 30 min, and particle size up to 5 mm. Closed mass and element balances were done for every set of parameters. As expected, amongst process variables the temperature was identified as the main factor influencing biomass pyrolysis. The temperature depending products yields could be fitted well by the double boltzmann approach due to the two-stage pyrolytic decomposition of biomass. Correlation of feedstock properties with different target parameters, including yields, product composition, heating values, remaining energy content in char, and char properties, was done by Spearman´s rank correlation and Pearson´s correlation for different temperatures. Biopolymer composition as well as alkaline content and total content of potential catalytic elements (Na, K, Ca, Mg, Fe) were identified as main factors influencing biomass pyrolysis product yields and compositions. Further correlations arise with fuel properties like volatile matter and ash content besides O/C atomic ratio. The obtained correlations can be mainly related to pyrolysis mechanisms. The received relationships were quantified by means of multiple regression models. Model evaluation was done by coefficient of determination, information criteria and mean squared errors. 42 regression models, based on different biopolymer contents and the total content of catalytic elements, were provided for the mathematical description of product yields for different process temperatures. Another 56 equations are suitable for the calculation of product properties like tar/oil and char composition, tar/oil heating value, and remaining energy content in the char at different temperatures. The predictability of the regression models was proved using another data set for apple pomace. The yields of char, gas, and condensate as well as the aforementioned product properties can be predicted very well, although, the predictability varies with the applied equation. Validation of the models by literature data was only possible for the char yield, because of the mentioned lack in suitable and complete data sets. Application of regression model to fixed bed char yields for different biomass and biogenous residues from literature resulted in a good predictability. Mathematical description of pyrolysis product yields and properties by means of regression models based on feedstock parameters is a promising approach to predict maximum yields at defined conditions and, therefore, to make an estimation of suitability of the biomass to different applications. Up to now such models do not exist. In general, the development of simple equations based on a few standardized parameters which are easy to determine is worthwhile. Hence, the results showed that the overall trend between different biomass feeds was often not predicted correctly using one-parameter models. This is due to the complex relationships between pyrolysis behavior and feedstock properties. Consequently, at least two parameter models, where the variables show the opposite trends, were most appropriate
Lee, Jae-Sung. "Etude de la pyrolyse basse température de charbons bitumineux et du craquage catalytique simultané des matières volatiles dégagées par la pyrolyse". Vandoeuvre-les-Nancy, INPL, 1990. http://www.theses.fr/1990INPL066N.
PETER, SANDRINE MULLER J. F. "ETUDE DES MECANISMES DE LA PYROLYSE FLASH ET DE PYROLYSE LASER PAR SPECTROMETRIE DE MASSE : APPLICATION AUX POLYMERES SYNTHETIQUES ET NATURELS /". [S.l.] : [s.n.], 1996. ftp://ftp.scd.univ-metz.fr/pub/Theses/1996/Peter.Sandrine.SMZ9638.pdf.
Peter, Sandrine. "Etude des mécanismes de la pyrolyse flash et de la pyrolyse laser par spectrométrie de masse : application aux polymères synthétiques et naturels". Metz, 1996. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1996/Peter.Sandrine.SMZ9638.pdf.
The purpose of this work is to compare the flash pyrolysis and the laser ablation/pyrolysis, connected to the gaz chromatography/mass spectrometry (gc/ms). The final aim is to microcharacterize synthetic and natural polymers such as hairs and fibers. After the explanation of the principles and the mechanisms of the thermal pyrolysis, we describe the apparatus involved in this work, in particular pyrolysis ovens, laser pyrolysis device and connections with gc/ms. In order to compare different pyrolysis modes, experimental results are displayed in two manners : characterization of the volatile molecules formed during pyrolysis and the compared study of the different mechanisms occuring in the three pyrolysis methods. First, two synthetic polymers were studied by flash pyrolysis ; the relative proportions of each monomer have been determined. From the results with the organic acids (MALDI), we draw the role of the decarboxilation and of the vaporization of the intact molecule as a function of the wavelength used. The same approach has been made concerning the amino-acids constituting human hair. Then, we have been in order to separate the thermal effects of the laser irradiation from laser desorption. Finally, we applied the three pyrolysis modes to human hair. Comparing the results with the amino-acids and polypeptides analysed in the same conditions, we characterized the pyrolysates from human hair. We identified the mechanisms involved in the breaking of the peptidic chain. For the first time, the laser ablation of a human hair been attempted
Thery, Serge. "Cinétique de pyrolyse en méthane : étude en système fermé et réalisation d'un réacteur ouvert". Bordeaux 1, 1985. http://www.theses.fr/1985BOR10551.
Donner, Matthias. "Synthese und Pyrolyse von metallocen-katalysierten Ethen-Norbornen-Copolymeren". [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980197465.
Krüger, Reinhard. "Pyrolyse- und Sinterverhalten Sol-Gel-abgeleiteter Al2O3-YAG-Fasern". [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969687540.
Margeriat, Alexandre. "Conversion catalytique des vapeurs de pyrolyse et molécules modèles". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1340/document.
Fast pyrolysis of biomass yields bio-oils with high levels of oxygen-containing components, high acidity and low stability. Further upgrading of these oils is necessary before they can be used as liquid fuels. Several low-cost strategies have been proposed for reducing the oxygen and acid contents including the catalytic conversion of pyrolytic vapors before vapor condensation. In this context, a first step in this work was the study of model molecules conversion, acetic acid and guaiacol, on different acid catalyst to understand reaction mechanisms and determine the best catalyst. In a second time, a semi-continuous pyrolysis test combined with a catalytic reactor was built and use to test the best acid catalysts found on model molecules, for the conversion of beech wood chips. A product recovery protocol was implanted to recover all the gas, liquid and solid fractions. Those fractions were characterized in depth by various techniques (?-GC, GC×GC, GPC, RMN…). A special focus was made on the quantification of monomers in the bio-oils by GC×GC. Mass balance reached 90% and carbon balance were established for some experiments. The performed characterizations as well as the comparison between catalytic and thermal experiments allowed to get more insights in the role of the catalyst on pyrolytic vapors conversion
Ayar, Ayhan [Verfasser]. "Modellierung der Pyrolyse in einer Kohlenstaub-Druckfeuerung / Ayhan Ayar". Aachen : Shaker, 2003. http://d-nb.info/117261086X/34.
Quirino, Waldir Ferreira. "Valorisation énergétique de déchets de bois par pyrolyse étagée". Nancy 1, 2000. http://www.theses.fr/2000NAN10220.
Ratte, Julien. "Modélisation d'un réacteur de pyrolyse lente de bois pollué". Pau, 2009. http://www.theses.fr/2009PAUU3019.
The slow pyrolysis is a solution of elimination and valuation of waste waste, that they are treated or not. It is an environment-friendly solution of treatment based on the thermal degradation of the organic matter. A mathematical model including the transfers of heat and mass and the chemical reactions of thermal degradation of a wooden particle was built. A spherical particle is warmed by a convective stream of nitrogen. The overall process is characterized by three big stages: 1) Drying of the sample; 2) Heating of the sample until the reactions of pyrolysis start; 3) Pyrolysis and production of char and volatile matters. The mathematical model is based on the concept of the method of volume averaging and allows to describe the internal profiles of several variables (temperature, moisture, wood concentration). This last one is then injected in a global model of industrial reactor. The final purpose is to build a tool to assist in designing and optimizing of industrial unit of wood waste
Le, Brech Yann. "Analyse des mécanismes primaires de pyrolyse de la biomasse". Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0106/document.
Current research studies focus on biomass thermochemical conversion to produce other energetic vectors more appropriate to be conveyed, such as electricity, gas or liquid products. Pyrolysis is the first mechanism occurring in all thermochemical processes for solid fuels conversion (combustion, gasification, pyrolysis). It controls in a large extent products (gas, condensables and char) distribution and composition. The prediction of pyrolysis products and the understanding of the chemical mechanisms are thus pivotal for developing thermochemical reactors. Extensive work has been conducted for more than one century but the important heterogeneity of biomasses and pyrolysis conditions make it difficult to encompass a global chemical mechanism. The aim of this study is to develop complementary analyses of pyrolysis products. Pyrolysis is conducted in a fixed bed reactor under slow pyrolysis conditions (5 K/min), for a wide range of final temperature (200°C and 500°C) and for different biomasses (miscanthus, douglas and oak). Various analytical methods have been used in order to characterise the pyrolysis products: nuclear magnetic resonance (carbon 13C and proton 1H NMR), Calorimetry, Thermogravimetry, GC/MS (Gas Chromatography and Mass spectrometry), LC/MS (Liquid Chromatography and Mass Spectrometry) and soft ionization mass spectrometry (Single Photo Ionisation SPI). Original analytical methods such as 2D NMR HETCOR 1H-13C (for the analysis of chemical moieties in char) and high temperature 1H NMR (for in-situ analysis of mobile protons) have been used. The latter allowed a novel characterization of the interaction between biomass and minerals during pyrolysis
Andersen, Erin R. "Thallium Removal from Drinking Water Using Pyrolusite Filter Media". DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7399.
Grzyb, Bartosz. "Preparation and characterization of mesophasic carbon materials enriched in nitrogen". Metz, 2003. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2003/Grzyb.Bartosz.SMZ0328.pdf.
The production of carbonaceous material enriched in nitrogen was done by several ways :1) by copyrolysis of mixtures coal tar pitch/ polymer (PAN and PVP) and 2) by ammoxydation of mesogenic carbonaceous material. By copyrolysis, the thermal behaviour of the blends has been more especially studied by TGA and on line gases analysis. In this case, we have demonstrated that the pitch play the role of radical scavenger during the thermal treatment. The XPS study of the produced solids shows the strong evolution of nitrogen functional groups according to the temperature. The optical texture of the solids have also been determined and discussed. By ammoxydation, we have demonstrated that the resultant solids have nitrogen surface functional groups. These groups were identified and quantified by XPS and infra red spectroscopy (in diffuse reflectance mode). Finally, some electrochemical properties of the studied solids are described and discussed
Hagenbucher, Roland. "Untersuchungen zur Pyrolyse von Kunststoffen und Kunststoffabfällen in der Wirbelschicht /". [S.l.] : [s.n.], 1989. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=8840.
Gerdes, Christian. "Pyrolyse von Biomasse-Abfall thermochemische Konversion mit dem Hamburger-Wirbelschichtverfahren /". [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=964083507.
Winkler, Jens K. "Pyrolyse und Anellierungsverhalten von Hetarenen Untersuchungen zur Darstellung von Heterofullerenen /". [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=959119914.
Steltz, Tatjana. "Kopplung der Curie-Punkt-Pyrolyse mit einem Ionenmobilitätsspektrometer zur Kunststoffidentifizierung". [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972778012.
Bec, Sandrine. "Micro-pyrolyse de couches minces de polymères précurseurs de céramiques". Phd thesis, Ecole Centrale de Lyon, 1992. http://tel.archives-ouvertes.fr/tel-00151134.
Dans un premier temps, l'analyse du comportement de dépôts pyrolysés sous différentes atmosphères est effectuée avec un dispositif de micro-pyrolyse spécialement développé pour cette étude. Il permet d'observer en microscopie optique la surface du dépôt en continu pendant le traitement thermique. Nous mettons ainsi en évidence plusieurs phénomènes pendant le chauffage. En particulier, nous montrons que la fissuration des dépôts se produit pendant la montée en température, vers 580°C sous azote ou sous argon. Des caractérisations chimiques montrent que, dans ces conditions, les dépôts sont du type SiCNO avec une couche oxydée (SiO2) en surface (épaisseur 100 nm environ).
Des modélisations mécaniques issues de la littérature, puis la construction d'un modèle monodimensionnel simple nous permettent de décrire la fissuration et le décollement des dépôts de manière plus quantitative.
La dernière partie de ce travail consiste en la détermination des paramètres principaux qui gouvernent cette fissuration. La caractérisation mécanique des dépôts à différents stades de la transformation du précurseur est effectuée par nanodureté. Nous montrons que la fissuration des dépôts coïncide avec un brutal accroissement des propriétés mécaniques du matériau (dureté et module d'Young) entre 550°C et 650°C, couplé à une augmentation importante du retrait à ces températures. Nous en déduisons que la fissuration résulte de la transition polymère/céramique.
Graf, Frank. "Pyrolyse- und Aufkohlungsverhalten von C2H2 bei der Vakuumaufkohlung von Stahl". Karlsruhe Univ.-Verl. Karlsruhe, 2008. http://d-nb.info/987168819/34.
Kruse, A. [Verfasser]. "Die Pyrolyse von tert.-Butylbenzol in überkritischem Wasser / A. Kruse". Karlsruhe : KIT-Bibliothek, 1994. http://d-nb.info/113283113X/34.
Gillet-Dominguez, Valérie. "Valorisation chimique des esters méthyliques d'huile de colza par pyrolyse". Vandoeuvre-les-Nancy, INPL, 1994. http://www.theses.fr/1994INPL124N.
Salouhi, Mohamed. "La pyrolyse du 1,2-dichloroéthane : une réaction radicalaire hétéro-homogène". Vandoeuvre-les-Nancy, INPL, 1989. http://www.theses.fr/1989NAN10246.
Ziegler, Isabelle. "Modélisation cinétique des dépôts de pyrocarbone obtenus par pyrolyse d'hydrocarbures". Vandoeuvre-les-Nancy, INPL, 2004. http://www.theses.fr/2004INPL045N.
This research work consists in developing a detailed homogeneous mechanism coupled to a heterogeneous mechanism describing the pyrolysis of propane and the reactions of pyrocarbon deposition at low pressure and high temperature. The experimentations, carried out in an ideal reactor, allow to deposit pyrocarbon, by propane pyrolysis, on carbon fibers. Ln addition to pyrocarbon, more than 25 hydrocarbons are quantified. This work shows the influence of the operating conditions on the kinetics of deposition and the composition of the gas phase. The reactions of pyrolysis are included in a homogeneous mechanism, which depends on the kinetic data of the literature. This model is validated on our experimental results in a wide range of temperature and residence time. A flow rate analysis allows to show the importance of some radicals. A pseudo-homogeneous approach is also proposed, it consists in modeling the de position reaction like a homogeneous reaction in gas phase
Marino, Emanuela. "Nanoparticules de carbone par pyrolyse laser : étude de l'incorporation d'hétéroatomes". Paris 11, 2004. http://www.theses.fr/2004PA112287.
Carbon nanoparticles are studied for their interesting properties in many application fields. This implies to understand and to characterise the specific properties of these nanoparticles. Laser pyrolysis is a versatile method for the synthesis of various nanoparticles and has been used successfully in the case of carbon nanoparticles. The aim of this work is to extend this research to the study of mixed carbon structures such as carbon/nitrogen or carbon/iron structures. These structures are indeed little studied and it is important to be able to determine the optimal experimental conditions to elaborate them by laser pyrolysis and to characterise their properties. In the case of carbon/nitrogen structures, we succeed in the incorporation of nitrogen in the powders in large amounts up to 20%. This high incorporation occurred by using a mixture of different gaseous precursors and allowed us to study the evolution of the structure as a function of the nitrogen incorporation rate in the powders. A comparative study between infrared spectroscopy and near edge x-ray absorption fine structure allowed to attribute the observed bands to an original structure. Indeed these bands could be explained by the interaction of a non bonding doublet of a nitrogen and the cn triple bond which can be present in two types of bondings : -c=n-cn or n-c=c-cn. For the carbon/iron compounds, this work showed how the laser pyrolysis of an aerosol mixture containing ferrocene leads to the synthesis of carbon nanopowders with different morphologies and structures. These powders contain always iron nanoparticles incorporated in the carbon matrix
Klaimy, Sophie. "Pyrolyse thermique et catalytique des polymères utilisés dans les emballages". Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1R056.
Over the past ten years, the production and consumption of plastics have grown significantly around the world due to their uses in a wide range of applications including packaging, agriculture, automotive or construction. In 2017, 342 million tons of plastics were produced worldwide among them around 65 million tons in Europe. The valorization of plastic waste by mechanical recycling or incineration are widely used but do not constitute a long-term solution. Thermal as well as catalytic pyrolysis appears as an attractive alternative. The research carried out in this PhD work focused on pyrolysis of plastics used in packaging such as polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyethylene terephthalate (PET). The thermal decomposition of virgin polymers and of a defined model mixture representative of plastic waste were studied by thermogravimetric analysis and flash pyrolysis. The quantity of each phases (gas, liquid, solid) were determined and the composition of the liquid phase analyzed. It was demonstrated that, within the model mixture, interaction between the polymers occurs leading to accelerate the decomposition process and to favor the formation of aromatic compounds. The use of zeolite (ZSM-5) as a catalyst for the pyrolysis of polyethylene, the most commonly used plastic in packaging, lead to a narrower distribution of pyrolysis products. The amount of catalyst was optimized and the effect of its acidity was studied. The most acidic ZSM-5 promotes the formation of aromatics and specifically products between C6 and C12 are obtained. The deactivation and regeneration of ZSM-5 respectively before and after pyrolysis was also investigated. The effectiveness of catalyst regeneration after several cycles of use was demonstrated. Finally, several catalysts with defined structure and acidities were synthesized. It was thus possible to conclude that both parameters play an important role in the composition and selectivity of the pyrolysis process
Ozagac, Matthieu. "Étude mécanistique de l'hydroconversion catalytique de bio-huiles de pyrolyse". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1170/document.
One of the thermochemical liquefaction processes used to transform lignocellulosic biomass into liquid is flash pyrolysis. The obtained bio-oils have limited end-user application due to their thermal instability, low heat capacity and immiscibility with hydrocarbons resulting from a high oxygen content. A promising upgrading process is the catalytic hydroconversion that performs a significant oxygen removal. However competitive reactions such as condensation or oligomerization can be observed. Regarding the bio-oil complexity, model molecules lead to a better understanding of those reaction. Investigated model compounds in this PhD. were D-glucose, furfural, acetic acid and guaiacol in water. Experimental tests were carried out in an isothermal 500 ml stirred batch reactor subsequently feed by 150 g mixture and 15 g of fresh reduced NiMo/?-Al2O3 catalyst. The reaction temperature varied from 200°C to 300°C during a reaction time up to 3 h. A H2 atmosphere was set to maintain a constant total pressure of 13 MPa during the run. Deoxygenation and side-reactions were observed through a gradual reactant addition in the studied mixtures using an original analytical strategy of liquid and solid effluents based on various technique. Furfural and D-glucose single hydroconversion lead to a wide range of by-products mainly issued from hydrogenation, dehydration, decarbonylation/decarboxylation or aldol reactions. A low quantity of carbon quantified by GC and LC in the liquid phase was observed during the conversion corresponding to the formation of soluble macromolecules which were detected by the size-exclusion chromatography (SEC) analysis. In a water medium, those products were prone to precipitate from 700 g/mol PS equivalent. 13C NMR of D-glucose’ solid residues revealed furanic and aromatic boundaries. Such compounds were likely formed through dehydration reactions. Regarding the final 4-component mixture, the presence of guaiacol decreased the solid production by solubilizing and/or reacting with macromolecules arising from D-glucose and furfural leading to the production of larger macromolecules (up to 5.000 g/mol) in the liquid phase. The same operational conditions were used with bio-oil to observe and characterize similar macromolecules formation and structures
Graf, Frank. "Pyrolyse- und Aufkohlungsverhalten von C2H2 bei der Vakuumaufkohlung von Stahl". Karlsruhe Univ.-Verl. Karlsruhe, 2007. http://d-nb.info/987104519/04.
Chehaidi, Sirine. "Nanopoudres multiéléments SiCNYO par spray-pyrolyse : synthèse et comportement thermique". Limoges, 2010. https://aurore.unilim.fr/theses/nxfile/default/45310e62-ab78-40fc-b024-2763a6731a1b/blobholder:0/2010LIMO4051.pdf.
The Si3N4/SiC composites, carried out from SiCN nanopowders, present an interesting properties for high temperature application. Powders with spherical shape and low size are at the origin of the existence of plasticity at high temperature of these materials. The obtention of dense and homogeneous Si3N4/SiC composites requires sintering aids such as Al2O3 and/or Y2O3. To promote the control of the composition in the final material and to obtain a homogeneous microstructure, the liquid synthesis route seems to be more promising. This method consists on the multielement precursor synthesis. This precursor must be adapted to the spraying process. This work has allowed to obtain SiCNYO prealloyed powders by a pyrolysis of the preceramic precursor issued from the dissolution of yttrium reagent into an organosilicon solvent. The atmosphere pyrolysis affects the chemical composition, the germination/growth mechanism and the microstructure evolution of the final material
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Pennequin, Florence. "Caractérisation des produits de thermolyse du poly(éthylène glycol) par différentes techniques analytiques". Lyon 1, 1995. http://www.theses.fr/1995LYO10242.
Loustalet, Delphine. "Etude de la pyrolyse de brais en unité pilote et industrielle". Pau, 1993. http://www.theses.fr/1993PAUU3022.
Hita, Corinne. "Biodégradation des triglycérides (graisses) dans les sols". Poitiers, 1997. http://www.theses.fr/1997POIT2364.
Surdyk, Dominique. "Etude expérimentale et modélisation de la dégradation thermique du dichlorométhane dans une flamme laminaire de prémélandge CH4/CH2Cl2/O2/N2". Lille 1, 1994. http://www.theses.fr/1994LIL10096.
Kharrat, Abdelmajid. "Réactivité radicalaire de peresters insaturés : accès à des esters cycliques". Bordeaux 1, 1985. http://www.theses.fr/1985BOR10579.
Lannuzel, Frédéric Marquaire Paul-Marie Scacchi Gérard. "Influence des aromatiques sur la stabilité thermique des pétroles dans les gisements". S. l. : INPL, 2007. http://www.scd.inpl-nancy.fr/theses/2007_LANNUZEL_F.pdf.
Salmon, Élodie Marquaire Paul-Marie. "Étude des mécanismes du craquage thermique par simulation dynamique moléculaire de géopolymères organiques avec un champ de force réactif (ReaxFF)". S. l. : INPL, 2008. http://www.scd.inpl-nancy.fr/theses/2008_SALMON_E.pdf.