Dissertations / Theses on the topic 'Gazéification'
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Paviet, Frédéric. "Vapo-gazéification étagée des ordures ménagères." Compiègne, 2007. http://www.theses.fr/2007COMP1721.
Full textIn recent years, the quantity of municipal solid wastes (MSW) has increased significantly in the EU and other industrialised and developing countries raising the question of its sustainable disposal management. Within the waste management hierarchy, thermal disposal especially gasification with energy recovery is a desired and viable option. The gasification of solid fuels such as biomass is one of the most promising technologies for thermo chemical conversion. This process leads to a fuel gas suitable for efficient gas turbines feeding. The successfful design and modelling of a gasifier requires reliable kinetic data. The purpose of this work is first to study the steam gasification kinetics of chars produced by municipal wastes pyrolysis. The MSW are modelled as a mixture of four organic constituents: paper, wood, plastics, and vegetables. The various char samples are obtained by pyrolysis of each waste constituent, in a fixed bed reactor. These chars are used as raw materials in steam gasification experiments. The kinetics parameters, with respect to H20, together with the influence of the char's physical properties are experimentally determined. A kinetic expression for the gasification reaction, based on the random pore model is deduced. Then 1D isothermal and non-equimolar reaction-diffusion model is developed in order to assess the diffusional effects taking place during steam gasification in a fixed bed. The model takes into account local chemical reaction rate and effective transport properties dependant on time and position within the char bed. Inter particle diffusion and structural changes of the char bed during the gasification are taken into account. The model shows a good agreement with the experimental results, obtained at various bed heights, and point out the relevant rote played by diffusional effects within a fixed bed reactor. The kinetic results are used to estimate, in a down dyaft gasifier, the total carbon yield conversion as a fonction of botte the mass fraction of stagnant zones within the bed char and of the characteristic length of these stagnant zones. Finally, in thermal treatment main of the initial energy is transformed into tar. The spontaneous tar decomposition by thermal treaent is investigated. The thermal cracking kinetic of MSW pyrolysis vapours is established
Amahzoune, El Mustapha. "Pyrolyse-flash et gazéification d'anas de lin." Toulouse 3, 1987. http://www.theses.fr/1987TOU30296.
Full textEnergetic 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
Le, Dirach Jocelyn. "Contribution à l'industrialisation d'un procédé de gazéification." Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL024N.
Full textDiversification of energy sources based on renewable energies must contribute to reduce the share of fossil fuels in power generation, in agreement with the European directives which impose to France to generate 21% of its energy from renewable energies before 2010.The present work reported in this manuscript focus on the industrialization of a wood gasification process for the production of heat and electricity. Experiments of wood fast pyrolysis were performed under various experimental conditions (flux density between 0.9 and 6.3 MW/m2, moisture between 0 and 60%) for understanding and analysis of fundamental phenomena related to the gasification of wood. The various products (char, condensible vapours and gases) are recovered and analyzed. The results help to determine the yields of each of the products for various experimental conditions.The numerical modeling of wood pyrolysis phenomena has been achieved on the basis of kinetic data found through literature review and then compared to the experimental results. Even if there is no perfect agreement, orders of magnitude are respected. These models are used as a basis to develop a gasification reactor model for Güssing DFB reactor, including the hydrodynamics description, wood pyrolysis, char gasification, vapours and gases reactions. This model is used to determine the efficiency of the reactor and its various operating parameters
Deydier, Alexandre. "Modélisation d’un réacteur de gazéification a lit fixe." Thesis, Pau, 2012. http://www.theses.fr/2012PAUU3012/document.
Full textOne of the thematics of the “Laboratoire Thermique Energétique et Procédés de Pau” is the study and the valorization of waste as pyrolysis, combustion and gasification for example. In this context, this work deals with modeling of heat, mass and momentum transport in a multiphase multi components reactive medium for a fixed bed gasifier. Conservation equations are first written for each phase. The macroscopic partial differential equations are expressed by integrating these microscopic conservation laws over a representative volume. This change of scale, described in this work, leads to a homogeneous system of equations. This model is applied to the case of the gasification of waste process of the Europlasma company named CHO-Power. The unsteady two-dimensional simulations of the problem allowed to highlight the different mechanisms present during the process and a number of locks in obtaining convergence path leading to the steady state
Schmitt, Nicolas. "Etude du comportement thermomécanique du charbon dans le cadre de la gazéification souterraine : analyse de la stabilité d'une liaison de gazéification." Paris 6, 1987. http://www.theses.fr/1987PA066618.
Full textMorin, Mathieu. "Gazéification de la biomasse en double lit fluidisé circulant : étude des réactions élémentaires de gazéification et de combustion du char et de reformage des goudrons." Thesis, Toulouse, INPT, 2017. http://www.theses.fr/2017INPT0089/document.
Full textThe thermochemical conversion of biomass at high temperature (>700°C) in Fast Internally Circulating Fluidized Bed (FICFB) is a promising alternative route to fossil fuels (oil, coal) to produce syngas which can be used in several applications. The aim of the present work is to develop methodologies as well as theoretical and experimental tools for determining the intrinsic kinetic of biomass transformations (biomass pyrolysis, char gasification and combustion, cracking and reforming of tars). Firstly, a fluidized bed reactor has been designed and built at the Laboratory of Chemical Engineering (LGC). This reactor can operate for temperatures between 20 and 1000°C with a well-defined gas supply (N2, O2, H2, H2O and tars). A sampling and analysis gas system enables the continuous quantification of the non-condensable gases and tars molar fractions. A hydrodynamic and thermal study enabled the determination of the operating conditions for each experimental study. Secondly, the char gasification and combustion was performed in the fluidized bed reactor. The influence of the operating conditions (temperature and compounds partial pressure) led to the modelling of the different solid transformation kinetics. Besides, in the case of char combustion, a reaction scheme was proposed and the kinetic obtained in the fluidized bed was compared to that obtained in a thermogravimetric analyzer. Finally, a study on the tar reforming in a fluidized bed reactor highlighted the effect of the reactive atmosphere on the reaction scheme of toluene conversion over olivine and char
Amri, Abdallah. "Contribution à la modélisation progressive d'un réacteur de gazéification du bois à lit fluidisé : application à l'intégration énergétique du réacteur dans la boucle de synthèse du méthanol." Châtenay-Malabry, Ecole centrale de Paris, 1987. http://www.theses.fr/1987ECAP0042.
Full textBoujjat, Houssame. "Modélisation, optimisation et extrapolation d’un réacteur solaire de gazéification de biomasse." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALI049.
Full textThe present thesis proposes to study a novel spouted bed solar reactor for biomass thermochemical gasification from laboratory to industrial scale by combining numerical simulations and lab-scale experimentations. The main objective is to provide new insights into the reactor operation in order to improve its performance, flexibility and industrial integration. A multiphysics numerical model of the reactor was developed using the Fluent© software for the simulation of solar steam gasification of wood particles. The model takes into account the two-phase solid/gas flow using the DPM (Discrete Phase Modelling) approach in interaction with radiation and chemistry. An experimental validation step at 1200°C showed Cold Gas Efficiencies higher than 1 thanks to the efficient valorization of solar energy and a Carbon Conversion Efficiency approaching 80%. The simulations provided key information on the particles solar conversion within the solar cavity and allowed to identify paths for improving the conversion. The use of inert bed materials as a heat transfer medium inside the cavity appeared judicious. This solution was examined both numerically using a granular Eulerian approach, and experimentally at 1200°C and 1300°C. A maximum relative improvement of the carbon conversion efficiency by 8% was this way achieved. The variability of solar energy is one of the critical obstacles hindering the scale-up of the technology. In order to ensure a continuous syngas production whatever the solar resource, the solar reactor was hybridized thanks to partial feedstock oxy-combustion. The study showed that the injection of a controlled amount of O2 is a relevant solution to overcome solar energy variability and to control the reactor temperature. A dynamic 0D model was then developed to predict the temperature and syngas production evolution at MWth scale according to two heating modes: solar-only and hybrid solar-combustion. Annual simulations were subsequently performed to predict reactor performance, reactants consumption and gas production volumes. These data were used to analyze the technical and economic feasibility of the process for the industrial production of hydrogen
Nowakowska, Milena. "Conversion thermique des goudrons provenant de la gazéification de la biomasse." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0092/document.
Full textTars are compounds limiting the optimal operation of thermochemical processes of biomass conversion. The reactions of these compounds were studied to better understand their formation, maturation and decay. The study of the decomposition of three model compounds from biomass was conducted with a jet stirred reactor. The studied compounds were anisole and guaiacol, representing the primary tars from lignin and the 5-methylfurfural, representing the primary tars from cellulose. The pyrolysis and the oxidation of these compounds were performed at atmospheric pressure, at a residence time of 2 s and at high dilution, and for a wide range of temperatures. The oxidation was carried out in stoichiometric conditions ([phi]= 1). Reaction products were quantified by gas chromatography and identified using mass spectrometry. Detailed kinetic mechanisms for the pyrolysis and oxidation (based on a combustion model for light aromatics) have been developed for each compound. Models predict well the conversion of reactants and the formation of the main products
Gerun, Luc. "Étude numérique et expérimentale de la valorisation énergétique du bois par gazéification." Nantes, 2007. http://www.theses.fr/2007NANT2061.
Full textGasification is a thermochemical process of biomass (wood waste, straw,…) conversion into fuel gas, which is then used to run boiler, engine or gas turbine and thus to produce “green” energy. Gasification can be divided into three main steps, which occur successively: drying/pyrolysis: the biomass is dried then converted into gas, tar and coke under the action of heat; oxidation: the produced gas is partially burnt with air to provide the heat necessary to the other endothermic chemical reactions; reduction: the produced coke reacts with gases and is converted into gas. The study of these three stages made it possible to identify, characterize and simulate their operation. The key-parameters are the heating rate and the final temperature for pyrolysis, the air flowrate and its injection velocity for oxidation, the temperature and the residence time for the reduction. All these observations led to making of a prototype, composed of three engines to separate the three stages physically. The objective is to optimize the parameters of operation to reduce the production of tar, one of the principal barriers to the development of the gasification. Its operation is promising because it produces a gas satisfying the tolerances of the engines: LHV of approximately 5,2 MJ. Nm-3, absence of heavy tar, PAH concentration lower than 10 Mg. Nm-3. It thus opens encouraging prospects to develop a commercial gasifier optimised for the installations of small to average power
Ourkiya, Rabah. "Couplage de réactions exo- et endothermiques : induction de la carboxy- ou de la vapogazeïfication de carbones par de faibles quantités d'oxygène vers 500°C." Vandoeuvre-les-Nancy, INPL, 1990. http://www.theses.fr/1990INPL036N.
Full textBelghit, Abdelhamid. "Etude theorique et experimentale d'un gazeifieur solaire de matières carbonees en lit poreux mobile." Perpignan, 1986. http://www.theses.fr/1986PERP0020.
Full textBennini, Souad. "Mise au point d'une méthode d'analyse des mécanismes de pyrolyse du bois à haute température à l'aide de matériaux marqués." Toulouse 3, 1989. http://www.theses.fr/1989TOU30147.
Full textDupont, Capucine. "Vapogazéification de la biomasse : contribution à l'étude de la phénoménologie entre 800 et 1000 °C." Lyon 1, 2006. http://www.theses.fr/2006LYO10219.
Full textVîjeu, Rãzvan Andrei. "Étude de la gazéification des déchets de bois : modélisation thermochimique pour la production des combustibles gazeux propres." Nantes, 2009. http://www.theses.fr/2009NANT2017.
Full textIn the actual economical and environmental context, favorable to the development of renewable energies, gasification proves to be a viable technology for the energetic valorization of biomass waste, and in particular of wood waste. The work presented in this report is part of a wider research oriented on staged gasification, in which the three main phases (drying/pyrolysis, partial combustion and reduction) have their own separate reactors. The theoretical study concentrates on the phases of drying/pyrolysis and reduction. The 2D model developed for the first phase is based on a nodal heat transfer method and uses simple mechanisms for thermal decomposition of wood and for mass transfer within the reactor. A similar model is also developed for reduction but in 1D configuration. It takes into account the reduction reactions with water, carbon dioxide, oxygen and hydrogen and also the water-gas shift reaction for the gas phase equilibrium. The two models are validated using experimental laboratory data or literature data. In a purely exploratory approach, the knowledge acquired during the theoretical study allowed the design and construction of a pilot gasifier, containing three reactors especially developed for the three phases. The experimental data obtained aids the process optimization and highlights the steps to be taken towards an eventual pre-commercial state
Lacroix, Nicolas. "Analyse du couplage digestion anaérobie - gazéification pour le traitement des boues d'épuration." Mémoire, École de technologie supérieure, 2014. http://espace.etsmtl.ca/1306/1/LACROIX_Nicolas.pdf.
Full textLemoine, Alan. "Gazéification pyrolytique de la graine de canola par lit jaillissant par plasma." Mémoire, Université de Sherbrooke, 2001. http://hdl.handle.net/11143/5485.
Full textPaquet, Antonin. "Reformage de gaz de synthèse primaire produit par gazéification de biomasse hétérogène." Mémoire, Université de Sherbrooke, 2010. http://hdl.handle.net/11143/5523.
Full textDjebabra, Djamal. "1ère partie : gazéification d'un charbon par plasma micro-onde de vapeur d'eau." Lille 1, 1990. http://www.theses.fr/1990LIL10152.
Full textChhiti, Younes. "Gazéification non catalytique des huiles de pyrolyse de bois sous vapeur d'eau." Thesis, Toulouse, INPT, 2011. http://www.theses.fr/2011INPT0064/document.
Full textEnergy production from ligno-cellulosic biomass via gasification technology appears as an attractive option in the current energy context. The combination of decentralized fast pyrolysis of biomass to produce bio-oil, followed by transportation and gasification of bio-oil in bio-refinery has appeared as one of the most economically viable methods for syngas (H2+CO) production. The objective of this work is to bridge the lack of knowledge concerning the physicochemical transformation of bio-oil into syngas using non catalytic steam gasification in entrained flow reactors. This complex process involves vaporization, thermal cracking reactions with formation of gas, tars and two solid residues - char and soot - that are considered as undesirable products. This is followed by steam reforming of gas and tars, together with char and soot conversion. To better understand the process, the first step of gasification (pyrolysis) and thereafter the whole process (pyrolysis + gasification) were studied. The pyrolysis study focused on the influence of the heating rate, the final pyrolysis temperature and the ash content of bio-oil on char, tars and gas yields. At the higher heating rate char yield is smaller than 1%. In addition, ash seems to promote polymerization reactions and causes a decrease of gas yield. Concerning gasification, the effect of temperature on syngas yield and composition was studied. An increase in the reaction temperature implies higher hydrogen yield and higher solid carbon conversion. A thermodynamic equilibrium calculation showed that equilibrium was reached at 1400°C. Finally, the soot formation and oxidation mechanisms were investigated through experiments in three different atmospheres: inert (pyrolysis), rich in steam (gasification) and in the presence of oxygen (partial oxidation). A semi-empirical model was proposed and validated. It is based on detailed chemistry to describe gas phase reactions, a single reaction using C2H2 concentration to describe soot formation and one main heterogeneous reaction to describe soot oxidation
Tagutchou, Jean-Philippe. "Gazéification du charbon de plaquettes forestières : particule isolée et lit fixe continu." Perpignan, 2008. http://www.theses.fr/2008PERP0876.
Full textBiomass gasification is considered today as a promising route for energy production, such as electricity, natural gas or synthetic biofuels. Mechanisms involved in such processes are very complex and need further understanding. In staged processes, the zone of gasification of carbon residue impacts significantly the energy efficiency and the quality of gas produced. This thesis improves the understanding of this reaction zone in order to optimize the design and the operation of reactors. The gasification of char from forestry woodchips has been precisely characterised in the case of both a single particle and a continuous fixed bed. We have measured the gasification kinetic of particles of different sizes and in various atmospheres using a "macro-ATG" type reactor. We noticed that between 800 and 1000 °C, the thickness of the particle is the characteristic dimension; the reaction of gasification is about three times faster in the presence of steam than it is with carbon dioxide. The results of the parametric study confronted with those of our numerical model, enabled us to identify the intrinsic kinetic constants of chemical reactions. In parallel, we modified our numerical model to take into account the complex evolution of carbon reactivity. Thus, we added the concept of "structural factor" relative to active sites. This allowed us to propose a new kinetic model in the case of a mixed atmosphere of CO2 and H2O. Furthermore, we studied the gasification of a continuous fixed bed experimentally using an original reactor, the CFiBR (Continuous Fixed Bed Reactor). Injection of superheated steam and a more elaborated instrumentation enabled us to determine profiles of temperature, concentration of gaseous species, char conversion, pressure and porosity of the bed. We have identified reactions zones within the bed and determined the relative importance of different reactions on the conversion of carbon, the production of synthesis gas and energy consumption
Omar, Faisal. "Contribution à l'étude de la gazéification et de la combustion des combustibles solides." Aix-Marseille 3, 1986. http://www.theses.fr/1986AIX30031.
Full textLemonon, Jérôme. "Valorisations énergétique et matière du revêtement de sol stratifié par pyrolyse & gazéification." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0338/document.
Full textSince a few years, energy challenges are appearing at the top of the list of the current concerns for the future. The forecasted end of fossil fuels, at the origin of 80% of currently consumed energy, is obviously accompanied by research about alternatives to provide for the future needs. The integration of an environmental care concerning the implementation of a sustainable development puts clearly ahead the assets of renewable energies which constitutes nowadays less than 15% of the worldwide production. Work suggested here deals with this scope of research and proposal for renewable primary energy sources with the recovery study of waste containing biomass and more precisely the case of laminated flooring. Among the various current recovering ways, incineration with the whole waste remains the most used one. The main drawback deals with the need for smoke treatment, the cost of which can be really high. It would thus seem to be judicious to look for another recovering issue. The suggested process is divided in the three following steps: - A pretreatment step through low temperature pyrolysis (275°C) making it possible a nitrogenous components separation of the elements (precursor able to form pollutants species) in deteriorating the fuel the less as possible to provide a maximum energy recovery in the following stage.- An energy recovery step, which constitutes the main goal of the process, through a high temperature pyrolysis (1000°C). Energy is recovered via syngas.- A material recovery step through two aspects in order to produce added-value material (particle boards and activated carbon), the consideration of which in the global economic assessment of an industrial installation could be interesting
Bassil, Georgio. "Gazéification de la biomasse : élimination des goudrons par lavage, étude expérimentale et modélisation." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10057/document.
Full textGasification of biomass is a promising thermochemical renewable energy resource. Among all biomass conversion processes, gasification by heat cogeneration / bio-SNG (Substitute Natural Gas) is the promising one. But still, one of the deadlocks to be raised is the reduction of the high level of tar present in the product gas. The objective of this work is to perform a data base which will be useful at the operation of tar removal from aqueous medium. The present work has mainly focused on the acquisition of bi and triphasic equilibrium data model molecules of tars - water - washing solvent. Such data are indeed essential for the development of the thermodynamic model for the modeling and the optimization of the washing process. Analyses of liquid phases in equilibrium have been performed by GC-FID or GC-MS. In some cases the concentration levels were particularly low (up to 10-10 mole fraction of anthracene in the aqueous phase). Reciprocal concentrations obtained and the partition coefficients which are deduced from the empirical correlation satisfy each of Hands and the Van't Hoff relationship. Liquid-liquid-vapor equilibrium of binary systems (water-extracting solvent) was studied with the static method. The concentrations of the phases in equilibrium were correlated by the NRTL and UNIQUAC models using the commercial software 'Thermodynamic Simulis'. The interaction parameters adjusted allow a good reproduction of experimental data
Billaud, Joseph. "Gazéification de la biomasse en réacteur à flux entrainé : études expérimentales et modélisation." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2015. http://www.theses.fr/2015EMAC0010/document.
Full textThe present work deals with biomass gasification in Entrained Flow Reactor (EFR) in the context of the development of new Biomass-to-Liquid processes. The objective of this study is to develop a comprehensive model to better understand the phenomena controlling biomass gasification in conditions representative of an EFR. Biomass pyrolysis and gasification of beech particles sieved between 315 and 450 µm have been studied between 800 and 1400°C in a drop tube furnace. The influence of H2O, CO2 and O2 addition on gasification products has been investigated and the tests have been simulated with a 1D model. The addition of H2O or CO2 leads to a significantly lower char yield. The main influence of these two oxidants in gas phase is the modification of major species composition with water gas shift reaction. With the addition of O2, the carbon conversion into gas is improved and the char and soot yields are significantly lower. The simulations are in very good agreement with the experimental results. Biomass pyrolysis and gasification of beech particles sieved between 1.12 and 1.25 mm have been studied in presence of O2. Between 800 and 1200°C the carbon conversion into gas is lower than with the smaller particles but at 1400°C the particle size has no influence. At last, the influence of O2 addition, particle size and pressure on biomass gasification has been studied in a pilot scale EFR. These experimental results have been satisfactorily simulated by adapting the 1D model
Milhé, Mathieu. "Pyrolyse de plaquettes forestières en lit fixe continu." Perpignan, 2013. http://www.theses.fr/2013PERP1239.
Full textPortela, Julien. "Déterminants moléculaires et spécificités du priming immunitaire chez le mollusque d'eau douce Biomphalaria glabrata." Perpignan, 2013. https://tel.archives-ouvertes.fr/tel-00941916.
Full textDi, Marcello Manuela. "Production continue de gaz issus de la gazéification de la biomasse (miscanthus) dans un réacteur à lit fluidisé circulant : caractérisation chimique des composés organiques lourds produits durant le procédé de gazéification." Thesis, Metz, 2011. http://www.theses.fr/2011METZ005S/document.
Full textGasification could be defined as a group of processes that converts solid or liquid fuels into a combustible gas. Therefore, biomass gasification can be employed to meet different market needs. Among the different gasification technologies available, fluidized bed gasifiers are very attractive because they take the advantage of the excellent mixing characteristics and high reaction rates of gas-solid mixtures. Miscanthus x giganteus (mxg) pellets and crushed and sieved almond shells have been used as biomass feedstock. Comparing the results obtained using the two biomasses at analogous operating conditions, no significant differences concerning the gas yield, gas composition and tar content could be observed. During the work, innovative catalytic hot gas filters for in-situ tar and particulate abatement, as well as two interesting Ni and Fe based catalyst have were tested in real gasification conditions. Further improvements have been obtained by combining the synergic catalytic effect of Fe-olivine and the catalytic filter candle, resulting in a efficient Tar abatement (-92% in the producer gas), and a consequently increase of gas yield by 72%. Also, the use of catalytic filter allows efficient particle separation so that the final result is a hot and clean fuel gas made available right at the exit of the gasifier reactor. The composition of tar was followed by HPLC as reference method. Other methods like HPTLC allow the separation of aromatic compounds according their number of aromatic rings. Quantification without separation was validated in order to control on line the production of tar during the gasification process
Lamarche, Pierre. "Contribution à l'étude expérimentale et à la modélisation de la gazéification étagée de biomasse en lit fixe." Nantes, 2011. http://www.theses.fr/2011NANT2093.
Full textReal alternative with combustion, the energy valorization of the biomass by gasification and CHP answers to the double problem of energy production and wood residues elimination. The work presented in this thesis is related to the development of a dimensioning tool for the continuous fixed bed and external heating pyrolysis reactors integrated into staged gasification process for small and middle power plants (< 500 kWe). This tool allows the prediction of the temperature fields and species concentrations within the bed according to the operating conditions (reactor geometry, wood mass flowrate, wall temperature) and biomass properties (moisture, particle type). Within the framework of this tool development, a staged experimental device made up of a fixed bed and external heating pyrolysis reactor, and of a batch gasification reactor was developed. The obtained transient temperatures profiles on the pyrolysis reactor allowed the validation of a batch pyrolysis model and the determination of a key parameter of the model: the effective thermal conductivity. At the conclusion of this validation, the model was extrapolated for the modeling of continuous pyrolysis, and a parametric study made it possible the limiting parameters identification during pyrolysis with external heating. Lastly, experimental results obtained on the gasification reactor of the experimental device are presented, and recommendations for the improvement of partial oxidation and char reduction stages are given
Sadikou, Yessoufou. "Étude d'un problème lié à la gazéification souterraine : modélisation et identification en angiographie numérisée." Compiègne, 1987. http://www.theses.fr/1987COMPD064.
Full textNitsch, Xavier. "Craquage et reformage des goudrons de gazéification de biomasse en phase homogène et hétérogène." Perpignan, 2012. http://www.theses.fr/2012PERP1122.
Full textOne of the main bottleneck in the development of industrial scale gasification of biomass is the formation of tars inside the reactor that prevent the direct use of syngas in energetic applications. The aimof this work is to study tar cracking in the homogeneous and heterogeneous phases at 850°C in the representative conditions of a dual fluidized bed gasifier. In order to achieve this, a fixed bed reactor (Aligator) and gas preparation and analysis devices were developed and validated. Conversion of phenol in the homogeneous phase, and then on catalysts (olivine, Fe/olivine and Ni/olivine) and on biomass chars was experimented. Results show a strong influence of H2 over the distribution of the products in the homogeneous phase, and a reaction scheme was proposed. An aging study of the catalysts didn’t show any substantial deactivation after 200 cycles of oxidation/reduction in the conditions of a circulating dual fluidized bed. Experiments with different gaseous atmospheres showed that a concentration of 10% of H2 O and 20% of H2 allow a very important improvement in the catalytic activity of olivine
Hiblot, Hélène. "Etude cinétique du reformage thermique des produits issus de la gazéification de la biomasse." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL028N/document.
Full textAdvanced applications, such as catalytic production of liquid fuels, request a high quality synthesis gas. Biomass may be a promising feedstock but the syngas needs to be drastically cleaned to reach the specifications. The high temperature homogeneous reforming (> 1300 K) seems a credible alternative to the catalytic way. The reforming kinetic at high temperatures in a reducing atmosphere has to be understood. If detailed mechanisms already exist for the combustion of hydrocarbons, sensitive reactions are different in this case. An experimental and modelling study of the steam cracking of small hydrocarbons have been performed. The experiments have been done in a plug flow reactor under atmospheric pressure. The kinetic influence of different gases of the syngas on the hydrocarbons conversion has been investigated. The behaviour of representative complex mixtures has been also studied as a function of the temperature. The most difficult species to reform is methane: temperature as high as 1700 K is necessary. A model derived from that for the combustion of light hydrocarbons was developed. The experimental trends are well reproduced. Carbon reforming appends mainly by reaction of OH radicals with unsaturated C₂ molecules, which are soot precursors. Process conditions necessary for high temperature methane reforming would then be favourable to undesirable soot formation
Berger, Etienne. "Étude de l’intégration des séparations membranaires dans les procédés de gazéification de la biomasse." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0183/document.
Full textGasification allows to convert biomass into a synthesis gas containing mainly H2, CO and CO2. This gas can be used as a fuel in engines or to produce synthesis natural gas (SNG). In practice, heavy aromatic species named tars (such as toluene, naphthalene, phenanthrene) are generated along with syngas. These species generate various practical problems. They damage the SNG catalysts (especially toluene since it’s the most abundant). If syngas is used in a combustion engine, the problems are linked to the heaviest tars that can condense. Therefore, syngas upgrading is a key step to allow a good use. Gas permeation across a dense polymer membrane is a technology that is used for several separations. In particular, silicone membranes (PDMS) are more permeable to organic vapors than to permanent gases. This property is ever used at high scale to remove light vapors from fluxes of air or of nitrogen at ambient temperature. The separation that is considered in this study uses this idea but the vapors are heavy and the temperature is 90°C; that is, quite a high level of temperature. The permeation of species through a membrane is ruled by sorption and diffusion laws. The sorption parameters have been measured and the diffusion parameters have been obtained from literature in order to allow simulations. These simulations, show that the use of a PDMS membrane seems to be a promising technology to upgrade syngas for a use in an engine. On the other hand, this technology seems unable to efficiently separate toluene from permanent gases (because of a too low selectivity); that is, this technology is not able to upgrade syngas for use in SNG production
Carlesi, Irina. "Etude d’un procédé de gazéification de biomasse en ambiance plasma sur bain de verre." Limoges, 2012. https://aurore.unilim.fr/theses/nxfile/default/d13afd63-c292-456b-ad3c-8103147e5249/blobholder:0/2012LIMO4012.pdf.
Full textA process for ligno-cellulosic biomass gasification is proposed: it allows to obtain a synthesis gas (mixture of CO and H2) that may be used for the production of liquid fuels. The current processes present drawbacks: they need a preparation of the biomass (drying and grinding), they produce pollutants (CO2, CH4 and tars) and biomass ash extraction may induce phenomena of fouling of the process. The process, considered here, proposes an original way of heating to eliminate some of these drawbacks or at least to strongly decrease them. It is based on an electric arc transferred between two graphite electrodes above a glass melt. Biomass is introduced by gravity at the top of the furnace and falls inside the arc volume on the melt surface. The energy, needed for the endothermic gasification reactions is provided by the electric arc and not by the consumption of a part of the biomass, that allows to increase the conversion yield of the biomass. So the high temperature (more than 1200°C) favors the gasification and decreases the formation of unwanted by-products by increasing tars cracking. The mineral melt has various functions. On one hand it allows "to store" inside the energy of the electric arc to transfer it to the biomass, increasing the energy yield. On the other hand it allows to increase the residence time of the particle in the hot atmosphere and therefore to avoid the biomass crushing. Furthermore, the mineral melt allows the incorporation of the remaining ashes. Besides the usual humidity of the wood (~ 20 % (mass)) provides directly in the atmosphere of the furnace the water necessary for the reaction of gasification: C6H9O4 + 2 H2O → 6 CO + 6,5 H2; so the stage of preliminary drying is avoided. Trials of beech wood gasification have been run with temperatures between 1200 and 1600°C: CO2 and CH4 are formed in small quantities, lower than 1 % (volume) for the first one and on the order of 0,01 % for the second, the quantity of tars detected during trials is on the order of about 10 mg. Nm-3, the conversion yield of CO from the biomass is between 52 and 68 % and the one of H2 is between 60 and 68 %, the optimal temperature for the process is about 1300°C: the conversion yield of carbon in dry biomass to CO is about 98 %(mass). A simplified model for the thermal transfer to biomass particle shows that the residence time corresponds with time obtained experimentally and allows to envisage a first sizing for an industrial reactor. A technico-economic approach was made from these results: the competitiveness of this process depends strongly on the energy return on the reactor; but the additional cost engendered by the lack of optimization is compensated by the decrease of the costs of biomass preparation and of the gas cleaning
François, Jessica. "Modélisation et évaluation environnementale des filières de cogénération par combustion et gazéification du bois." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0071/document.
Full textBiomass is one of the most promising renewable energy source in Europe. Its use as a substitute to fossil energy is expected to mitigate climate change. However, potential drawbacks are also feared with large scale development. In order to assess the environmental impacts of the biomass-to-energy chain, we firstly developed a model of the bioenergy system, from the forest to the energy production. We focused on two biomass power plants for combined heat and power (CHP) production: one is based on the conventional direct combustion process while the other is based on the more advanced gasification process. Gasification offers higher electrical efficiency, but its development is still facing technical difficulties. In case of the gasification process, we defined the best operating conditions regarding energetic and exergetic efficiencies, as well as the syngas quality requirements. Secondly, we calculated the carbon and mineral flows taken from the forest through energy wood harvesting, along with the forested area required to feed the CHP plant. The other resources and emissions related to the plant operation were also predicted. We observed that more extensive forestry practices led to an increase in the mineral exports. Finally, we evaluated the environmental performance of the two biomass CHP plants using life cycle assessment (LCA). Within French energy context, we found that both CHP technologies had very similar impacts with a slight advantage toward the combustion process. It appears of particular benefit to replace current fossil energy systems with biomass CHP plants to reduce climate change
François, Jessica. "Modélisation et évaluation environnementale des filières de cogénération par combustion et gazéification du bois." Electronic Thesis or Diss., Université de Lorraine, 2014. http://www.theses.fr/2014LORR0071.
Full textBiomass is one of the most promising renewable energy source in Europe. Its use as a substitute to fossil energy is expected to mitigate climate change. However, potential drawbacks are also feared with large scale development. In order to assess the environmental impacts of the biomass-to-energy chain, we firstly developed a model of the bioenergy system, from the forest to the energy production. We focused on two biomass power plants for combined heat and power (CHP) production: one is based on the conventional direct combustion process while the other is based on the more advanced gasification process. Gasification offers higher electrical efficiency, but its development is still facing technical difficulties. In case of the gasification process, we defined the best operating conditions regarding energetic and exergetic efficiencies, as well as the syngas quality requirements. Secondly, we calculated the carbon and mineral flows taken from the forest through energy wood harvesting, along with the forested area required to feed the CHP plant. The other resources and emissions related to the plant operation were also predicted. We observed that more extensive forestry practices led to an increase in the mineral exports. Finally, we evaluated the environmental performance of the two biomass CHP plants using life cycle assessment (LCA). Within French energy context, we found that both CHP technologies had very similar impacts with a slight advantage toward the combustion process. It appears of particular benefit to replace current fossil energy systems with biomass CHP plants to reduce climate change
Marcilio, Nilson Romeu. "Catalyse par le calcium de la gazéification par l'air à basse température d'un charbon sous-bitumeux." Lyon 1, 1989. http://www.theses.fr/1989LYO10138.
Full textLe, Bolay Nadine. "Etude cinétique de la vapogazéification de cokes en lit fluidisé." Toulouse, INPT, 1988. http://www.theses.fr/1988INPT022G.
Full textLaramée, Lucie. "Vue systémique de la gestion du risque environnemental application à la gazéification des déchets solides." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq26387.pdf.
Full textPageot, Justin. "Etude d’un procédé de décontamination du 14C par carboxy-gazéification des déchets de graphite nucléaire." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112423/document.
Full textThe decommissioning of French gas cooled nuclear reactors (UNGG), all arrested since 1994, will generate 23,000 tons of graphite waste classified Low Level and Long Lived and notably containing 14C. The aim of this thesis is to study a new method for selective extraction of this radionuclide by CO2 gasification.The multiscale organization of virgin and irradiated graphite has been studied by a coupling between microspectrometry Raman and transmission electron microscopy. With the neutron fluence, the structure degrades and the nanostructure can be greatly changed. In extreme cases, the lamellar nanostructure nuclear graphite has become nanoporous. Furthermore, these damages are systematically heterogeneous. An orientation effect of "crystallites", shown experimentally by ion implantation, could be a cause of these heterogeneities.This study also showed that from a specific fluence, there is an important development of nanoporous zones coinciding with a dramatic 14C concentration increase. This radionuclide could be preferentially concentrated in the nanoporous areas which are potentially more reactive than the remaining laminar areas which could be less rich in 14CThis process by CO2 gasification was firstly tested on "analogous" non-radioactive materials (mechanically milled graphite). These tests confirmed, for temperatures between 950 and 1000 °C, the selective and complete elimination of nanoporous areas.Tests were then carried out on graphite waste from Saint-Laurent-des-Eaux A2 and G2 reactors. The results are promising with notably the quarter of 14C inventory extracted for a weight loss of only few percent. Up to 68 % of 14C inventory was extracted, but with an important gasification. Thus, this treatment could allow extracting selectively a share of 14C inventory (mobile or linked to nanoporous areas) and allows imagining alternative scenarios for graphite waste managing
Teixeira, Gabriel. "Gazéification de charbon de granules de bois : comportement thermochimique et mécanique d’un lit fixe continu." Thesis, Toulouse, INPT, 2012. http://www.theses.fr/2012INPT0010/document.
Full textMulti-stage gasification of biomass leads to the production of a clean synthetic gas that can easily be used for electrical and/or thermal energy. However, optimization of these processes in terms of conversion yield and flexibility regarding the type of biomass is a major industrial challenge. To that end, a key stage of the process was specifically studied in this thesis: char gasification in a continuous fixed bed reactor. Granulation is the solution proposed for making use of low density or small particle-size biomasses. The performance of two wood chars – made from wood chips and pellets – was studied at the same time using experimental and numerical tools. Experiments were first conducted in a very highly instrumented pilot reactor, reproducing this zone of the process. The profiles measured, namely temperature, gas composition, bed density and particle velocity formed a unique database revealing reactor performance. A very reactive zone under 5 cm thick was thus located at the top of the bed, or even significant compaction leading to a drop in particle velocity, in a ratio of 8. Granular char gasification led to the same final conversion rates and synthetic gas compositions as for the chars derived from wood chips. A numerical model of the study zone was then developed, based on solving conversion equations combined with reaction kinetics, using COMSOL software. Taking into account bed compaction and the apparent kinetics of the heterogeneous reactions on a particle scale in the reaction source terms were two specificities of the model. It enabled satisfactory reproduction of the profiles of the physical magnitudes measured, for various operating conditions and for the two charsstudied. Use of this model is already providing new and complementary experimental information; it will eventually make it possible to optimize the industrial process
Capart, Richard. "La gazéification du bois : étude expérimentale et théorique de la pyrolyse du bois brut et des réactions d'oxydation du charbon de bois avec le dioxyde de carbone et la vapeur d'eau." Compiègne, 1991. http://www.theses.fr/1991COMPDE91.
Full textGirods, Pierre. "Procédé multi-étagé de valorisation de déchets bois type panneaux de particules." Thesis, Nancy 1, 2008. http://www.theses.fr/2008NAN10026/document.
Full textWithin the environmental contexts of power generation and waste disposal, the present works deals with the validation and the optimisation of a multistage thermo chemical process of particleboard waste conversion (enhancement). These wastes are mostly associated with urea formaldehyde and melamine formaldehyde resins which contain a huge amount of nitrogen. Nitrogen causes the production of pollutants such as ammonia, isocyanic acid, cyanhydric acid and NOx… during classical thermo chemical process (combustion, pyrolysis and gasification). The process studied aims in a first time to remove nitrogen species from waste to produce a combustible solid and in a second time to convert this residual solid in a combustible gas. The first step consists in a low temperature pyrolysis (250°C to 400°C) during 3 to 15 minutes and assumes to eliminate 70 % of the initial nitrogen content for all studied conditions. The pyrolysis and/or the pyrolysis / gasification under water of the residue are then studied between 800°C and 1000°C. The higher temperature of reaction (1000°C) improves the production of gases and the energy efficiency of this second step and allow the production of hydrogen and carbon monoxide rich gases. The pyrolysis / gasification under water allows a total conversion of the solid which optimises the energy efficiency of the process. However, the pyrolysis under nitrogen produces a lower amount of gases but helps to catch a part of the nitrogen in the residual char. The char then produced is converted through an activation step, in an active char containing nitrogen functionalities with high adsorption capacities, especially for the trapping of phenol or other aromatic compounds in liquid phase. This multistage is thus a interesting way to enhance low cost raw matter like particleboard waste
Vonk, Gwendal. "Caractérisation de la gazéfication de combustibles solides de récupération (CSR) en vue d'optimiser leur utilsation dans une unité de cogénération par gazogène." Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S075/document.
Full textGasification is a thermochemical conversion process converting solid fuel into synthetic gas (syngas), containing H2 and CO. Sorting waste to produce SRF aims to allow a better energy recovery of waste, while satisfying environmental regulations. This study focuses on energetic and environmental performances of the air gasification of SRF (wood, tire, plastics, sewage sludge) using downdraft fixed bed reactors at pilot and industrial scale. Analytical procedures allow quantification of syngas composition as well as pollutant contents (sulfur, nitrogen, tars, heavy metals) in gasification outlet streams, considering raw wood as a reference. SRF Wood gasification performances are identical to Raw Wood. However adding 20%w of SRF Tire, Plastics or Sewage Sludge to SRF Wood leads to a decrease in H2 and CO contents, balanced by an increase in light hydrocarbons (CH4, C2), resulting in a similar syngas calorific value, ranging between 4.9 and 5.4 MJ/Nm3. Gasification performances are slightly lower with SRF mixes, ranging between 35 and 49%, while reaching 48 to 52% for Raw Wood and SRF Wood. Compared to Wood, only nitrogen containing pollutants are in higher concentrations with SRF Wood. In the case of SRF mixes, tars, sulfur and nitrogen containing pollutants are in higher concentrations. Moreover, heavy metals contents are higher in fine particles than in chars, resulting in a particular post-treatment
Ould, Lemine Mohamed. "Étude technologique, expérimentale et numérique de la conversion thermochimique de la biomasse : Développement d'un procédé de carbonisation et gazéification en suspension." Paris, CNAM, 2002. http://www.theses.fr/2002CNAM0425.
Full textThe objective of this work is to produce vegetable coal and clean gas to energy ends starting from the vegetation wastes by te development of a new technology of carbonization and gasification of the biomass in suspension. The whole work is articulated around three large shutters. The first shutter aims at the development of a process of carbonization of straw and the development technological of the process. The advantages of this technology lie mainly at the compactness of the engines, which results in a notable reduction of the costs, simplicity in mechanical engineering, which facilitates its adaptation in the countries in the process of development, and the flexibility of the installation by simple adjustment of primary air. The second shutter is an attempt at modeling of the carbonization of the straw in the engine designed like a phenomeon of turbulent combustion diphasic non-premixed in poor medium. To model the operation of the engine of process, we adopted a Eulero-Lagrangian model coupled to a pdf supposed with two sclarars. The interest of the application of methode pdf to non-premixed turbulent combustion resides in the possibility of introducing the chemical term of source exactly. The system of the equations of the various assessments was solved by a finit cells method with separated operators. The third shutter is devoted to the application of the process of carbonization to the valorization of agricultural waste and particularly the balls and the rice straw in the local context of a developing country. It is indeed not only a question of developing a new energy technology, but also of taking care of the adequacy of the solution suggested with the local constraints. The panorama of the world energy context emphasized to us the principal charachteristics of the problems energy/environnement and particularly in the developping countries
Michel, Rudy. "Gazéification catalytique du Miscanthus X giganteus et vaporeformage d'un composé modèle : production de gaz de synthèse." Thesis, Metz, 2009. http://www.theses.fr/2009METZ044S/document.
Full textThis study presents the gasification of Miscanthus X giganteus (MXG). The MXG presents many advantage (high yield, perennial crop, easily harvesting…) so it’s a good candidate in terms of renewable energy sources. Several works have been carried out in the agricultural field, but this study is the first dealing with gasification in order to produce a syngas. The first part of this work concerns the study of gasification in fluidized bed reactor with olivine-based catalysts. The results obtained in different tests gave a good gas yield (CO + H2) comparable to others biomass. The catalyst characterisation by XRD and SEM is related to the properties of olivine (mechanical strength, recycling), while Ni-olivine gave much better results. Tar analysis by FTIR and GC/MS showed the presence of mainly PAH at high temperature (>800°C).The second part of this study deals with the steam reforming of methylnaphthalene which is representative of the tar composition issued from the MXG gasification. The steam reforming performed with the same catalysts as in the case of gasification. In addition to the main reaction, this study allowed us high lights the existence of secondary reaction such as the water gas shift reaction. Moreover these tests confirmed the high efficiency of Ni-olivine for tar removing. An overall mechanism was proposed with the important role of catalytic oxygen issued from water decomposition
Jimenez, Lucia. "Comportement et stratégies de gestion des espèces inorganiques dans une installation de gazéification de la biomasse." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0025/document.
Full textThe purpose of this work is to analyze the condensation phenomena of inorganic species aerosols in a biomass gasification process. Indeed, during gasification, lignocellulosic biomass is transformed, in between 900 and 1500°C, into a Syngas. Some inorganic species initially present in the ash, are partly volatilized in chlorides (KCl, NaCl), and condense when the syngas cools down. These compounds may then, induce corrosion, blockages and deactivation of the catalysts used in further synthesis. The understanding and modeling of these species condensation may help to their management, and also to the imitation of the encountered difficulties. An experimental and analytical set-up, existing n the lab, allowed us to perform condensation tests from gaseous KCl and NaCl, under experimental condition close to the industrial gasification ones for an entrained flow reactor, especially for two cooling rates (1000 and 300K/s). The influence of the different parameters (presence or not of preexisting particles like soot and simulated by carbon particles, inorganic salts concentration, salts mixture…) on the vapor condensation phenomena, was performed for both cooling rates. Globally, the experimental results showed that, without carbon particles, the inorganic species condensation induce the formation of very small new particles by homogeneous nucleation. With carbon particles, this vapor tends to condense on the preexisting particles, which allows to reduce the wall deposits by about 10wt %. The mixture behavior is found to be in between the individual salt ones. A particle agglomeration effect is also evidenced at 300K/S, linked the increase of the residence time in the cooling part of the set-up. The SOPHAEROS software, developed by IRSN for the fission product transport and condensation in a nuclear power plant, was adapted to the experimental conditions of this work. The validation of this tool was obtained, comparing calculation and experimental results. It was then used to determine the main condensation and deposits phenomena varying the inorganic salt nature, their concentration, the presence of carbon particles and the cooling rate. It was showed that, the three main involved phenomena, occurring in the quench part of a gasification reactor, without carbon particles, are the direct wall condensation of the vapor, the homogeneous nucleation (favored at high cooling rate, 1000K/s), and gravitational settling deposits. When carbon particles are included, heterogeneous nucleation is predominant upon homogeneous one. The modelling could allow us to explain the behavior differences related to the local variation of salts partial pressure and saturation vapor pressure, as well as the influence of both cooling rates on the condensation results. Finally, some industrial possible solutions to decrease the wall deposits are proposed as a conclusion of the work
Balland, Michael. "Gazéification de biomasse en lit fluidisé : étude phénoménologique de l’agglomération liée à la fusion des cendres." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2020/document.
Full textImproving the knowledge on the driving phenomena of agglomeration during fluidized-bed conversion of biomass (700-1000°C) is essential to predict its occurrence at industrial scale. Agglomeration is due to liquid phase formation (molten salts and/or molten silicates) coming from the melting of inorganic species contained inside the biomass (ash). Their presence leads to bed materials defluidization, reducing the process efficiency and even going up to a “blockage” of the reactor. The phenomenology of agglomeration is investigated with three experimental approaches, using simulant and real materials, at three different scales, and with a temperature ranging from ambient one to 1000°C. The analysis of the mechanisms underlying the bed agglomeration indicates that the liquid formation is the single limiting parameter for agglomerates formation. This phenomenon leads to an increase of the apparent diameter of the bed particles and at the same time to a decrease of their density. These modifications can be seen as a shift among the Geldart’s classification, from the B to the D-class. Concerning the hydrodynamic aspect, the bed defluidization is due to the agglomerates segregation at the bottom of the reactor. This phenomenon contributes to degrade the homogenous fluidization gas distribution across the reactor. The total bed defluidization occurs for a very low liquid fraction in the bed (few % vol. of bed materials). Based on these results, a simplified model has been proposed in order to predict the operating time before defluidization of the reactor, taking into account the biomass composition and simplified operating conditions
Lorcet, Hélène. "Contribution à l'étude et à la modélisation de la pyro-gazéification de biomasse par plasma thermique." Limoges, 2009. https://aurore.unilim.fr/theses/nxfile/default/cc4ce49b-1e76-4b09-8a06-085f31cc6d32/blobholder:0/2009LIMO4047.pdf.
Full textThis work is devoted to the study of an innovating allothermal process consisting in the thermochemical transformation of bio-oil by using thermal plasma in order to produce a high-value syngas. More precisely, the present study aims to understand and model the mechanisms playing a key role in the gasification of a liquid jet of bio-oil injected in a plasma cross-flow. First, a literature survey on the phenomena and modelling of the plasma – liquid interactions is presented. It led to the definition of a methodology combining an experimental and a numerical approach. The experimental works showed the effect of three main parameters during the conversion of organic compounds under thermal plasma conditions: the ratio between the specific plasma enthalpy to reaction enthalpy, the nature of the plasma-forming gas and the geometry of bio-oil injection. Lastly, the numerical results, obtained with Fluent software, confirmed and made it possible to extrapolate the experimental trends. Nships between the 3rd order NLO properties of tellurites and their structural arrangements (entities connection, tellurium lone pair)
Demol, Rémi. "Production d'hydrogène issu de gazéification de biomasse : modélisation, analyse technico-économique et environnementale de solutions innovantes." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0322.
Full textMinimizing the impacts caused by climate change imply the replacement of fossil fuels low greenhouse gas emitting energies. The hydrogen energy vector is forecasted to contribute to decarbonizing a part of industry and the uses of transport and mobility. Yet hydrogen is produced nowadays almost exclusively from fossil fuels and is dedicated to industrial applications.This work focuses on the production of hydrogen from a renewable resource, wood chips a by-product of the forest industry. Due to the nature of the fuel considered, small plant units are chosen (a limited supply area, short-distance transport of the resource). Pyrogasification processes transform this combustible into a synthesis gas (CO, H₂, CH₄, CO₂) under the effect of heat input (pyrolysis) or an oxidizing agent (gasification) consisting of oxygen and water vapor.To evaluate the relevance of these pyrogasification processes, they are studied and modeled with Aspen Plus®. Particular attention is put on the synthesis gas cleaning process. This syngas contains tars which should be reduced for the ultimate use of the gas. For this purpose, a partial oxidation unit is envisaged and modeled from a detailed radical kinetic mechanism. The purified gas can then be enriched in H₂ with Catalytic Reforming and Water Gas Shift reactors. The separation of the hydrogen produced is another crucial step and conventional technologies are not always suited to the gas produced. When a single technology cannot achieve the separation, a hybrid process combining membrane and adsorption technologies is adopted. The heat produced by the process is recovered in a heating network.In order to evaluate the relevance of these options, both from a financial and sustainable development point of view, a techno-economic analysis is carried out as well as a life cycle analysis. These processes clearly offer a virtuous alternative for the production of different vectors: hydrogen, heat and even bio-char. But under current market conditions, these industries are unable to reach financial equilibrium without public support