Th. univ.--Sci. pétrolières--Paris 6, 1992. / Diplôme délivré en association avec l'Ecole nationale supérieure du pétrole et des moteurs. Bibliogr. p. 163-170. 1993 d'après la déclaration de dépôt légal.

Thèses (M.Sc.A.)--Université de Sherbrooke (Canada), 1999. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.

Catalytic cracking fractional colurnn is the most important production device for refining enterprises in China. Its main products are car gasoline and diesel fuel. The yield and quality of these two kinds of products decide directly the economie efficiency of enterprises. In order to increase the economic efficiency of enterprises, it is needed to better adjust and control the quality of car gasoline and diesel fuel. Because fluidized catalytic cracking unit (FCCU) is in closed state, it is impossible to observe actual production process manually. But if people cannot timely master product quality condition, it is impossible to adjust effectively the technological parameters in order to control product quality. But at present, it takes four hours to obtain quality level of products if using the method of manual sampling testing. If it is as this, production process cannot, based on the analyzed results, be timely adjusted. Therefore, developing the real-time product quality intellect forecasting and analysis system of fractional column and realizing forecasting and analysis on-line have important theoretic meaning and value in engineering application. This system can real-timely forecast product quality of fractional colurnn, and can also real-timely analyze the factors affecting the products. So, the adjustment oftechnological parameters is more targeted, and shortens adjustment time, and increases efficiency. It is no doubt that the economic efficiency will increase. The thesis, taking fractional colurnn of fluidized catalytic cracking unit (FCCU) as research target, with the aim of forecasting product quality level of fractional column, establishes quality forecasting model through the method of neural network, and speculates the critical technological parameters that are hard to measure or impossible to measure at all through the technological parameters that are easy to measure. The system first finishes interactive interface between control system and operator with the functions of dynamic display and real-time data acquisition through configuration software DCS (Distributed Control System), which can supervise, control, activate and manage the whole system. Then it will realize product quality forecasting of fractional colurnn through the method of combining utility function based on average level and neural network. Finally it will realize the analysis of factors affecting product quality through the method of combining fuzzy technology and neural network. The thesis, through system configuration and using neural network technology to forecast product quality of fractional colurnn and analyze the factors affecting product quality, combines fuzzy technology and neural network which play their respective advantages to finish the display and control of operation state of fractionation system and realize real-time forecasting and analysis. The online forecasting system of product quality of catalytic cracking fractional colurnn based on the method mentioned above is developed for many small and medium petrochemical enterprises. The aim is to transform the equipments under the present condition of small and medium petrochemical enterprises with no change in the hardware of the original DCS (Distributed Control System) of refining enterprises. Therefore, this system has many advantages such as small investment, short transformation time and easy realization, etc. Currently, this system has been tried on the fluidized catalytic cracking unit (FCCU) in Tianjin First Petrochemical Plant in China. The operating result shows that the value and laboratory value of dry point of car gasoline and solidifying point of diesel fuel forecasted real-timely in this model have better goodness of fit, satisfying the requirements of product quality index. The test result shows that the technical path and method using neural network technology to forecast product quality put forward in the thesis is feasible. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Catalytic cracking, Fractional column, Neural network

La dégradation catalytique du PMMA a été réalisée avec succès à des températures inférieures à 300°C. L’utilisation de zéolithe comme catalyseur a permis de réduire la température de réaction par rapport aux procédés classiques de dégradation thermique. On a montré que la distribution des produits de réaction obtenus en réacteur discontinu dépend des propriétés acides du catalyseur, tandis que la composition de la fraction liquide est directement liée à la sélectivité de forme du catalyseur. Un procédé continu à lit fixe a été développé qui a permis d’obtenir le monomère MMA comme produit principal. L’augmentation de la température de réaction de 200 à 270°C a montré un effet positif sur le rendement en produit liquide. Cependant, des températures de réaction supérieures ont favorisé le craquage du monomère en produits gazeux. Une désactivation significative de la zéolithe ZSM-5 a été observée après 120 heures d’opération, entraînant une diminution du rendement en produit liquide. La régénération des extrudés de ZSM-5 cokés a pu être réalisée par ozonation à basse température - inférieure à 150°C. On a étudié les effets de la température, du débit de gaz et de la concentration en ozone sur l’élimination de carbone. Le décokage par l’ozone a débuté dès 50°C et montré un optimum à 100°C (avec une conversion de 80%). Des températures plus élevées ne se sont pas avérées bénéfiques, en raison de la forte limitation de la diffusion interne de l’ozone qui confine en surface la production de radicaux et donc le processus de régénération. Dans les conditions optimales, l’ozonation a presque complètement restauré l’activité de la zéolithe sans en endommager la texture et les sites actifs, comme le montrent les résultats de craquage du PMMA obtenus avec le catalyseur ainsi régénéré. / Catalytic degradation of PMMA was successfully performed at temperatures below 300°C. The use of zeolite catalyst could reduce reaction temperature in comparison with an ordinary thermal degradation process. It was found that the product distribution obtained from batch experiment depends on zeolite acid properties whereas the composition of the liquid fraction is directly related to the shape selectivity of the catalyst. A continuous fixed bed process was designed that allowed to obtain MMA monomer as main product. The increase of reaction temperature from 200 to 270°C showed a positive effect on the liquid product yield. However, at higher temperatures, the light product was further cracked into gaseous products. Significant deactivation of ZSM-5 catalyst was observed after 120 hours of operation, resulting in a decrease in liquid product yield. Regeneration of the coked ZSM-5 extrudates was achieved by oxidation with ozone at low temperatures, below 150°C. The effects of temperature, GHSV and inlet concentration of ozone on carbon removal efficiency were studied. Carbon removal with ozone started at 50°C and reached a maximum of 80% at 100°C. Higher temperatures were not beneficial due to the strong limitation of ozone diffusion which confines radical production then the regeneration process to the outer surface. In optimal conditions, ozonation almost fully restored the zeolite activity without damaging the texture and active sites of zeolite, as shown from the results of regenerated catalyst in PMMA cracking

L’objectif de la recherche proposée dans cette thèse est d’apporter une meilleure compréhension au mécanisme de la torréfaction de la biomasse et de proposer des méthodes pratiques afin d’améliorer l’efficacité de ce processus. Quant au mécanisme, la torréfaction de deux échantillons de biomasse lignocellulosique des forêts du Québec (le faux-tremble et le bouleau) et leurs constituants principaux tels que la lignine, la cellulose et l’hémicellulose est étudiée en détail en utilisant différentes techniques expérimentales et un modèle cinétique a été développé pour décrire la cinétique de leur torréfaction. Notre étude sur le mécanisme et la cinétique de torréfaction de la biomasse révèle également une faible vitesse de torréfaction de la biomasse, ce qui nous a motivés à proposer et développer une nouvelle méthode de torréfaction impliquant des liquides ioniques dans le but de stimuler la vitesse de torréfaction de la biomasse. Bien que la torréfaction améliore les propriétés physicochimiques de la biomasse en tant que combustible, la production d’hydrocarbures oxygénés (sous forme de volatils) de la biomasse lors de la torréfaction réduit son énergie globale. Dans le but de récupérer l’énergie des volatils, une nouvelle combinaison de la torréfaction de la biomasse et de la combustion des volatils dans une boucle chimique de combustion (Chemical Looping Combustion) a été étudiée dans cette thèse. À cet effet, les minéraux ultramafiques abondants et préalablement broyés, largement disponibles dans la province de Québec, ont été testés en tant que transporteurs solides d’oxygène conduisant à près de 96% de conversion des volatils à 700°C dans un réacteur CLC. Comme travail supplémentaire, nous étions également intéressé à explorer l’application potentielle des résidus miniers contenant une quantité considérable de fer pour le craquage catalytique de goudrons produits pendant les processus de gazéification de la biomasse. À cet effet, le potentiel de deux résidus miniers et des minéraux renfermant du fer obtenus de diverses activités minières au Québec a été comparé à celui de l’olivine (connu comme minéral actif pour le craquage du goudron). / The aim of the proposed research was to provide a better understanding of the mechanisms of biomass torrefaction and to propose practical methods to improve the efficiency of this process. As for the mechanism, torrefaction of two woody biomass samples from Quebec forests (aspen and birch) and their main constituents, i.e., lignin, cellulose and hemicellulose is studied in details using different experimental techniques and a kinetic model is developed for their torrefaction. Our studies on the mechanism and kinetics of biomass torrefaction also revealed the slow rate of biomass torrefaction which motivated us to propose and develop a new ionic-liquid assisted torrefaction process with the aim of increasing the rate of biomass torrefaction. Although torrefaction improves the physicochemical properties of biomass fuel, release of oxygenated hydrocarbons (in the form of volatiles) from biomass reduces its overall energy. To recover volatiles energy, a new combination of biomass torrefaction and chemical looping volatiles combustion was studied. In this regard, the already comminuted, abundant and cheap iron and magnesium bearing silicate minerals found widely in the form of mining residues in the province of Quebec were tested as solid oxygen carrier and up to 96% of volatiles conversion at 700°C was achieved in CLC reactor. As a supplementary work, we were also interested to explore the potential of mining residues containing sizeable quantities of iron for catalytic cracking of tar released during the gasification of biomass. For this purpose, iron-bearing mining residues and minerals obtained from the mining activities in Quebec were evaluated comparatively to olivine (known as an active mineral for tar cracking) for benzene cracking in simulated syngas. It was found that chrysotile showed up to four-fold increase in benzene and methane conversion than olivine.