Carbon dioxide levels in atmosphere are linked with a number of adverse environmental impacts including climate change. CO2 utilization is one of the available technologies to reduce CO2 emissions released into atmosphere by its conversion into value added products. Hydrogenation of CO2 into hydrocarbons (with methanol being an intermediate) can be achieved in a single-pot using bi-functional catalysis system composed of metal/metal-oxide and zeolite. In this study, activated novel indium cobalt (InCo) and zeolite beta samples (BEA) were used for the conversion of CO2 into a hydrocarbon mixture rich of iso-paraffins via methanol in a single pot. The objective was to investigate the effect of zeolite beta acidity (represented by SiO2/Al2O3 ratio) and the configuration of the reactor on the overall performance of the above mentioned bi-functional system. Three samples of zeolite beta with different SiO2/Al2O3 ratios were synthesized in-house (Beta-20, Beta-100 and Beta-300) and used along with commercial beta as methanol to hydrocarbons catalysts. XRD patterns of the synthesized samples showed that all of the obtained samples are zeolite beta with high crystallinity. Adsorption-desorption isotherms of the studied zeolites revealed micro-mesoporosity of the samples. Analysis of SEM images suggests that the particles of the studied samples are of a similar range of size (100-200 nm). Each zeolite sample was used to fill two reactor configurations: dual bed and mixed bed. Samples were tested at a temperature of 300 oC, a pressure of 50 bar and CO2:H2 ratio of 1:4 except for Beta-100 sample which was tested at a CO2:H2 ratio of 1:3. CO2 conversion is a characteristic of the methanol synthesis catalyst (InCo) and it ranged between 15% to 20% for all cases. Dimethyl ether (DME) generation in dual bed configuration was much faster and at much higher rates than in mixed bed configuration for all tested samples, indicating that mixed bed configuration is more stable for this particular system. Heavier hydrocarbons (C6 and C7) are generated in higher amounts over low acidic zeolite beta than over beta of high acidity. More acidic zeolite beta, however, was found to be more stable than beta of less acidity.

La stabilité des carburants en phase liquide est de premier ordre dans le domaine du transport. Par exemple, les carburants, les lubrifiants ou les additifs doivent être stables de leur production jusqu'à leur utilisation. Cette thèse a pour but de développer et de valider une méthodologie alliant l’acquisition de données expérimentales et le développement de modèles cinétiques pour l'autoxydation en phase liquide.Expérimentalement, une approche complémentaire a été mise en place pour obtenir à la fois des données de réactivité globales via un appareil PetroOxy et des profils d’espèces via un autoclave instrumenté.Numériquement, une méthodologie basée sur un générateur de mécanismes est proposée pour obtenir une chimie détaillée en phase liquide. Les paraffines linéaires et branchées sont étudiées comme des carburants modèles représentatifs de l'autoxidation de carburants réels afin de valider l’approche proposée. Ces familles chimiques sont représentatives de la composition des carburants réels et alternatifs.La réactivité des n-paraffines de C8 à C16 ainsi que d’isomères de l’octane a été étudiée en PetroOxy sur la gamme de température 373-433 K. Puis, des profils d’espèces détaillés de la phase gaz et de la phase liquide ont été obtenus durant l’étude de l’oxydation du n-C8 et du 2-methylheptane dans un autoclave à 383 K et 10 bars. Des mécanismes cinétiques détaillés ont été développé pour toutes les molécules jusqu’à C14. Les mécanismes reproduisent qualitativement la formation des espèces majoritaires lors de l’autoxidation des alcanes ainsi que les tendances observées liées à la longueur de chaîne et la ramification. L’analyse des mécanismes cinétiques a mis en avant le rôle prédominant des radicaux peroxy (ROO) et peroxy-hydroperoxyde (HOOQOO) dans la consommation de carburants modèles.Cette étude a permis d’améliorer la compréhension des processus d’autoxidation des alcanes linéaires et branchés. L’étude de nouveaux systèmes permettra d’améliorer la compréhension globale des processus d’autoxidation et, de réduire l’écart de compréhension existant entre l’autoxidation des carburants réels et des carburants modèles. / Liquid phase stability is a major concern in the transportation and the energy fields. Relevant examples are fuels, lubricants and additives which have to be stable from their production to their application (engine, combustors). This thesis aims to develop and validate a complete methodology combining both experimental data acquisition and the development of kinetic models for liquid phase autoxidation.The experimental methodology is based on a complementary approach to obtain (i) a global reactivity descriptor (Induction Periods) and (ii) detailed species profiles respectively using a PetroOxy device and an instrumented autoclave. Numerically, the presented methodology includes detailed liquid phase mechanisms generation with an automatic mechanism generator (RMG). Normal and iso-paraffins were selected as fuel surrogates for autoxidation to validate the developed methodology. They were selected regarding their large contribution in fuel composition and their growing interest as drop-in fuels.The reactivity of both n-paraffins from C8 to C16 and several C8 iso-paraffins was investigated over a wide temperature range (373-433 K) in the PetroOxy with liquid phase analyses. Then, detailed species profiles from the autoxidation of both n-octane and 2-methylheptane in autoclave were obtained at 383 K and 10 bars. Detailed liquid phase mechanisms were developed for all molecules tested up to C14. Mechanisms qualitatively reproduce the overall phenomenology of the chain length, the branching and the major species profiles observed experimentally. Mechanisms analysis allow to identify the main consumption pathways of alkanes through peroxy (ROO) and peroxy-hydroperoxide radicals (HOOQOO) over the temperature range investigated (373-473 K).This study permitted to increase the comprehension of autoxidation processes involved in normal and branched alkanes. The study of new chemical systems will increase the global comprehension of autoxidation processes and in fine it will reduce the gap between the current autoxidation knowledge and the real fuel autoxidation.