Cinza leve de carvão, resíduo gerado em usina termelétrica, foi usada para sintetizar zeólita por meio de tratamento hidrotérmico com solução de NaOH. A cinza leve (CL-2) e a zeólita sintética (ZM-2) que foi predominantemente identificada como hidroxi-sodalita foram utilizadas como adsorventes dos corantes aniônicos índigo carmina (IC) e reativo laranja 16 (RL16) de soluções aquosas. Nos processos de adsorção, os efeitos de tempo de contato, concentração inicial de corantes, pH, massa de adsorventes e temperatura foram avaliados. O estudo cinético de adsorção demonstrou que os resultados apresentaram melhor ajuste ao modelo de pseudo-segunda ordem e que adsorção de superfície e difusão intrapartícula participaram no mecanismo de adsorção. Os parâmetros termodinâmicos demonstraram que a adsorção foi espontânea em todos os processos de adsorção. Os processos de adsorção foram de natureza endotérmica para todos os sistemas, com exceção do sistema IC/ZM-2, em que foi exotérmico. Os dados de entropia mostraram a ocorrência do aumento da desordem na interface sólido/solução durante a adsorção em todos os sistemas, exceto novamente no IC/ZM-2, no qual se verificou a diminuição da desordem na interface. As isotermas de adsorção ajustaram-se à equação linear de Langmuir. As capacidades máximas de adsorção foram 1,48 mg/g para o sistema IC/CL-2; 1,13 mg/g para IC/ZM-2; 0,96 mg/g para RL16/CL-2 e 1,14 mg/g para RL16/ZM-2 à temperatura ambiente. O estudo de dessorção realizado com água, com soluções aquosas ácidas e com solução aquosa básica demonstrou ser ineficiente tanto para a recuperação dos corantes quanto para a regeneração dos adsorventes. / Coal fly ash, a waste generated in coal-fired electric power plant, was used to synthesize zeolite by hydrothermal treatment with NaOH solution. The fly ash (CL-2) and this synthesized zeolite (ZM-2) that was characterized as hydroxy-sodalite were used as adsorbents for anionic dyes indigo carmine (IC), and reactive orange 16 (RO16) from aqueous solutions. Effects of contact time, initial dye concentration, pH, adsorbent mass, and temperature were evaluated in the adsorption processes. The kinetics studies indicated that the adsorption followed the pseudo-second order kinetics and that surface adsorption and intraparticle diffusion were involved in the adsorption mechanism. The thermodynamics parameters demonstrated that the adsorption was spontaneous for all adsorption processes. The enthalpy data confirmed the endothermic nature for all adsorption processes except for IC/ZM-2 system which was exothermic. The entropy data showed an increased disorder at the solid/solution interface during the adsorption for all systems except for IC/ZM-2 whose negative entropy value indicated a decreased disorder at the interface. The adsorption isotherms were closely fitted to the Langmuir linear equation. The maximum adsorption capacities were 1.48 mg/g for the IC/CL-2 system; 1.13 mg/g for IC/ZM-2; 0.96 mg/g for RO16/CL-2, and 1.14 mg/g for RO16/ZM-2 at room temperature. The desorption study carried out with water, with acid aqueous solutions, and with an alkali aqueous solution showed to be inefficient both for recovering the dyes and regenerating the adsorbents.

Les catalyseurs d’hydrocraquage et d’hydroisomérization sont bifonctionnels, avec une fonction hydro-déshydrogénante et une fonction acide, une zéolithe protonée, pour isomériser et craquer les alcènes. Par dynamique moléculaire ab initio avancée, et avec prise en compte explicite des effets thermiques (300 – 500 K), nous avons étudié les mécanismes d’isomérisation et de craquage d’alcènes C7 dans la zéolithe chabazite dans le but d’obtenir des constantes de vitesse fiables et d’interpréter la distribution des produits.Par la méthode blue moon, nous avons établi les premiers profils d’énergie libre d’isomérisations d’alcènes C7, avec des carbocations intermédiaires (et des états de transition cyclopropanes protonés, PCP), reliant des isomères di- à tri- et mono- à di-branchés (Sections III et IV). Nos simulations démontrent que les effets dynamiques et l’échantillonnage correct des rotamères jouent un rôle crucial sur la stabilité des intermédiaires et des états de transition. Ces effets ne pouvaient pas être décrits par les précédentes études de DFT statiques. Les barrières bien plus basses pour l’isomérisation de type A sont ainsi retrouvées, et expliquées par un état de transition mou, alors que l’état de transition de l’isomérisation de type B est contraint, à cause de la formation d’un edge PCP. L’étude des réactions de craquage avec les mêmes méthodes (Section V) éclaircit le rôle des cations secondaires. Pour la première fois, nous identifions les états de transitions des β-scissions. Nous déduisons de cette analyse des constantes de vitesse ab initio qui pourront être utilisées dans un modèle cinétique pour prédire l’activité et la sélectivité du catalyseur. / Hydrocracking and hydroisomerization catalysts are bifunctional, with a hydro-dehydrogenation function and an acidic function, typically an acid zeolite, to isomerize and crack alkenes. With advanced ab initio molecular dynamics approach, and explicit simulation of the effects of temperature (300 – 500 K), we investigate the mechanisms of isomerization and cracking reactions of C7 alkenes within the chabazite zeolite in order to provide reliable rate constants and explain the observed products distribution. By blue moon sampling, we established for the first time, the free energy profiles for the isomerization of C7 alkenes in zeolites, with carbenium ions as intermediates (and protonated cyclopropane (PCP) as transition states), connecting di- to tri-branched, and mono- to di-branched alkene isomers (Sections III and IV). We demonstrate that the dynamic effects with the correct sampling of rotational conformers play an important role to quantify the stability of the key intermediates and transition states. These effects could not be captured by previous static DFT simulations. The much lower barriers for type A isomerization mechanisms are thus recovered, and assigned to a loose transition state, while the transition state of type B isomerization is tighter, due to the formation of an edge PCP. The study of cracking reactions (Section V) with the same methods, unravel the role of secondary cations. For the first time, we identify the structures of transition states involved in the β-scission mechanisms. From this analysis, we deduce the ab initio- rate constants that could be used in future kinetic modeling to predict activity and selectivity of the catalyst.

Les zéolithes sont largement utilisées en catalyse. Un enjeu majeur est d'obtenir des cristaux nanométriques qui offrent des perspectives prometteuses dans la conception de catalyseurs acides plus actifs et plus sélectifs, notamment pour les procédés de conversion des coupes lourdes pétrolières. L'obtention de ces nano-cristaux peut résulter de l'utilisation d'inhibiteurs de croissance. Cette thèse s'est attachée à identifier deux familles de composés organiques limitant la croissance des cristaux. Pour la première, l'inhibition est envisagée par adsorption de composés organiques (polycations, acides aminés...) sur la surface des cristaux en formation. Cette étude a été réalisée en suivant une méthodologie d'expérimentation à haut-débit et a conduit à des cristaux de zéolithe Y (FAU) de 300 nm par l'ajout de L-lysine. La seconde famille est dérivée de l’approche de l’équipe de Ryoo et consiste en l’utilisation de composés bifonctionnels comportant une fonction structurante et une fonction inhibitrice de croissance. Cette étude a démarré par la synthèse de zéolithe MFI. La modélisation moléculaire a permis d'identifier un mono-ammonium alkylé favorisant la formation de nanofeuillets de zéolithe ZSM-5 d'épaisseur voisine de 2 nm. L'étude cinétique a révélé par ailleurs que cette zéolithe est synthétisée à partir d’un polysilicate lamellaire formé in situ. Cette stratégie d'identification, couplée à une méthodologie d'expérimentation à haut débit, a alors été appliquée à la synthèse des zéolithes EMC-1 (FAU) et EMC-2 (EMT), et a conduit à l'élaboration de nouveaux agents structurants et composés bi-fonctionnels. / Zeolites are widely used in catalysis. One of today’s major challenges is to obtain nanometer-sized crystals, offering promising prospects for the design of more active and more selective acid catalysts, in particular for heavy oil conversion processes. Zeolite nanocrystals can be obtained by using growth inhibitors. This thesis focused on the identification of two families of organic compounds limiting the crystals growth. For the first one, the growth inhibition is favored by the adsorption of organic compounds (polycations, amino acids…) on the surface of growing crystals. This study was conducted using a high-throughput experiment methodology and led to zeolite Y (FAU) crystals of 300 nm by the addition of L-lysine. The second family is derived from Ryoo’s team approach and consists of the use of bifunctional compounds including one structure-directing function and one growth-inhibiting function. This study started with the synthesis of MFI zeolite. The molecular modelling allowed identifying an alkyl mono-ammonium directing the formation of 2 nm-thick nanosheets of zeolite ZSM-5. The kinetic study revealed that this zeolite is synthesized from a lamellar polysilicate formed in situ. This identification strategy, coupled to a high-troughput experiment methodology, was applied to the synthesis of zeolites EMC-1 (FAU) and EMC-2 (EMT) and conducted to the elaboration of new structure-directing agents and their bifunctional counterparts.

Des films composites et nanocomposites ont été élaborés par la méthode du casting à partir d’amidon natif de manioc. Ils ont été plastifiés par le glycérol et renforcés par des chargesminérales synthétiques de zéolithe Beta et de beidellite sodique. L’influence du type de charge, de l’état de la charge (lyophilisé ou non-lyophilisé ou séchage à l’air) ainsi que du taux de charge sur les propriétés mécaniques et barrières à la vapeur d’eau des films correspondants a été étudiée. Les valeurs de la solubilité dans l’eau et de la perméabilité à la vapeur d’eau des échantillons renforcés par des nanocristaux de zéolithe Beta lyophilisés sont plus grandes que celles du film de contrôle. Une augmentation significative des propriétés mécaniques, en particulier le module d’Young de ces films a aussi été observée. Une amélioration de la perméabilité à la vapeur d’eau des films composites contenant des cristaux de beidellite sodique et des films nanocomposites contenant des nanocristaux de zéolithe Beta a été trouvée. Tous les films ont été caractérisés par diffraction de rayons X. / Composite and nanocomposite films were prepared by casting method, using native cassava starch. The films were plasticized with glycerol and reinforced with synthetic Beta zeolite nanocrystals and Na-beidellite crystals. We studied the effect of the filler contents and type on the mechanical and water barrier properties of the resulting films. We found that filmsreinforced with lyophilized Beta zeolite nanocrystals present both high water solubility (WS) and high water vapor permeability (WVP) values compared to those of the pristine film. A drastic increase of the mechanical properties, especially in the Young’s modulus, of these films was also observed. An improvement of the WVP was found for composites prepared from Na-beidellite crystals and for nanocomposites from non-lyophilized Beta zeolite nanocrystals. All the films were characterized by X-ray diffraction.

Un des enjeux majeurs des procédés membranaires concerne le développement de nouveaux matériaux de filtration stables dont les propriétés texturales et structurales permettent d'orienter la sélectivité des membranes de nanofiltration. En particulier, l'utilisation de matériaux zéoliihiques comme couche filtrante a montré qu'après un traitement chimique adéquat, ces matériaux pouvaient acquérir des propriétés de sélectivité très particulières. Ce travail de thèse propose la synthèse, la caractérisation et l'optimisation de membranes de nanofiltration tubulaires en utilisant une zéolithe de type MFI. Plus particulièrement, des films mono et bicouches de zéolithes de type MFI ont été préparés sur un support tubulaire macroporeux asymétrique en alumine. La diffraction de rayons X et la microscopie électronique à balayage ont permis de déterminer la cristallinité, l'homogénéité et l'épaisseur des filins déposés (7 à 15 i_trn). La manométrie d'adsorption d'azote a été utilisée pour vérifier si la porosité après mise en forme restait accessible, ainsi qu'à déterminer la niasse de zéolithe déposée sur le support tubulaire en alumine. La perméabilité hydraulique, qui caractérise l'hydrodynamique d'une membrane, a été déterminée par filtration d'eau déminéralisée. Cette étape dite « de conditionnement » est nécessaire pour parvenir à un état de performance stable de la membrane (état d'équilibre), La perméabilité hydraulique de la membrane mono et bicouche MFI diminue rapidement au début de la phase de conditionnement, et finit par se stabiliser au bout de 15 heures de filtration pour atteindre une valeur minimale de 1,08 x tem-2 et 1,02 x 10-15 m3.ni-2 respectivement. La sélectivité et les performances de filtration de ces membranes vis-à-vis de différents types de solutés (ioniques, molécules organiques, mélanges) ont été analysées à l'issue de la phase de conditionnement. Les résultats obtenus sont très encourageants, ils ont fait l'objet de plusieurs articles de recherche. / Zeolites are very well-known materials especially for their controlled porosity, their crystalline structures, but also for the different applications where they can be used (catalysis, air treatment,...) . During the past ten years, a lot of developments have been done on the preparation of zeolite membranes for pervaporation applications. The present work explores new developments in the preparation zeolite membranes dedicated to the filtration of salty water. More particularly, we prepared MFI films on specific macroporous alumina tubular supports used for nanofiltration applications. There are different key steps which influence the formation of the MFI films: the cleaning procedure of the substrats, the hydrothermal synthesis conditions, the use of a secondary growth method for when preparing a bi-layered membrane. A complete characterization of the mono and the bi-layered membranes was carried out using various techniques, such as X-ray diffraction, scanning electron microscopy, X-ray fluorescence, energy dispersive X-ray spectroscopy, mercury porosimetry and nitrogen sorption measurements. Results show that a dense, continuous and highly crystallized thin film of MFI bas been obtained on the u-alumina support after the secondary growth experiment. The weight of zeolite deposited on the support was also estimated by nitrogen sorption measurement using the method of mass assessment. The MFI membrane was stabilized by pure water filtration tests until the hydraulic permeability reached a plateau. This conditioning step was necessary to reach an equilibrium state of the hydraulic membrane performances. Particularly, hydration of the MFI layer was a crucial step of the conditioning process, which leads to the modification of the MFI surface properties. The hydraulic permeability of the mono and bi-layer MFI membrane decreased rapidly at the beginning of the conditioning process, and stabilized alter 15 hours to reach 1.08 x 10.141113.m.2 and 1.02 x 10-15 m3.m-2 respectively. Filtration tests were then carried out with a neutral molecule (VB 12) in order to evaluate the mean pore radius of the mono and the bi-layered membranes. A rejection rate of 5% was obtained with the monolayer MFI membrane, while it reaches a value of 50% with the bi-layered one. These results lead to mean pore radius corresponding to 6.4 and 1.7 mn respectively. It menus that even alter the synthesis of the second MFI layer, the membrane porosity remains higher than the porous diameter of the zeolite. Filtration may occur at the interface of the MFI crystals.

La distillation fractionnée des coupes pétrolières brutes se révèle insuffisante, pour répondre seule aux besoins en carburants et génère de fortes quantités de distillats à longue chaîne carbonée (C20-C50). Cette coupe d’hydrocarbures peu valorisable est ainsi transformée en molécules hydrocarbonées plus légères, par le biais de deux procédés : le craquage catalytique en lit fluidisé ou l’hydrocraquage. Ce dernier permet le craquage sélectif des hydrocarbures essentiellement en gazole et kérosène. Les catalyseurs acides utilisés sont « bifonctionnels » : une matrice zéolithique USY (zéolithe Y ultra-stabilisée) favorise le craquage des hydrocarbures, pendant qu’un sulfure mixte ou un métal noble greffé catalyse les réactions d’hydrogénation et de déshydrogénation. L’objectif de ce travail de thèse consiste à maximiser la sélectivité en distillats moyens, en diminuant le temps de séjour des molécules d’hydrocarbures dans la structure zéolithique, afin de réduire les réactions de surcraquage. Pour cela, il a été choisi de synthétiser directement des nanocristaux de zéolithe Y sans agent organique structurant, avec un rapport Si/Al le plus élevé possible. Cette propriété leur confère une meilleure stabilité lors des post-traitements, indispensables pour atteindre le rapport Si/Al des zéolithes USY actuellement utilisées. Grâce à l’élaboration d’une nouvelle stratégie de synthèse, des nanocristaux compris entre 20 et 90 nm avec un rapport Si/Al variant de 2,2 à 2,6 ont été obtenus. Puis, l’obtention de la forme protonée de ces nanocristaux (90 nm) a été étudiée et des mesures d’acidité ont également été effectuées. / The fractionated distillation of crude oil is not sufficient to cover all the fuel needs and produces large amounts of long chain carbon distillates (C20-C50). Thus, these hydrocarbons are transformed into lighter hydrocarbon molecules by two processes: fluid catalytic cracking or hydrocracking. The latter allows the selective cracking of hydrocarbons essentially in gas oil and kerosene. The acid catalysts used are “bifunctional”: a zeolite matrix USY (ultra-stabilized zeolite Y) performs the hydrocarbons cracking, at the same time a sulfide or a noble metal catalyzes hydrogenation and dehydrogenation reactions. The aim of this work is to maximize the selectivity to middle distillates by decreasing the residence time of hydrocarbon molecules in the zeolite framework. For this, it was chosen to directly synthesize zeolite Y nanocrystals with the highest possible Si/Al ratio, in a SDA-free medium. This property gives them a better stability during the post-treatments essential to reach the Si/Al ratio of the currently used USY zeolite. Thanks to a new synthesis strategy, nanocrystals between 20 and 90 nm with a Si/Al ratio varying from 2.2 to 2.6 were obtained. Then, the protonated form of these nanocrystals (90 nm) was studied and acidity measurements were also carried out.

A degradação de rejeites de polímeros sintéticos tem sido o foco de crescente atenção, devido ao seu uso potencial como combustível e como fonte de produtos químicos. O aproveitamento de rejeitas poliméricos contribui para a solução dos problemas de poluição. O uso de catalisadores adequados pode facilitar a degradação térmica de polímeros sintéticos, a qual pode ser monitorada por métodos termoanalíticos. Este trabalho apresenta um conjunto de atividades envolvendo estudos de síntese e caracterização de catalisadores zeolíticos de estrutura faujasítica (zeólita HY e o silicoaluminofosfato SAPO-37), para serem utilizados na degradação térmica do polietileno de alta densidade (HDPE). A fim de avaliar a atividade catalítica destes materiais zeolíticos utilizou-se Termogravimetria (TG), análise térmica diferencial (DTA) e calorimetria exploratória diferencial (DSC). Os parâmetros cinéticos do processo de degaradção térmica do HDPE sem e com catalisador foram calculados usando-se o método integral a múltiplas razões de aquecimento de Flynn e Wall bem como o método de Vyazovkin (Model Free Kinetics). Promoveu-se também o monitoramento dos produtos formados na degradação térmica do polímero com e sem catalisador utilizando-se um sistema simultâneo e acoplado TG/DTA-GC/MS. Os resultados obtidos, mostraram que os materiais zeolíticos facilitaram o processo. / Degradation of waste synthetic polymers has been the focus of increased attention because of their potential use as fuels or chemical resource. Besides, recycling of polymers from waste products can contribute to solve pollution problems. The use of suitable catalysts can enhance the thermal degradation of synthetic polymers, which may be monitored by thermoanalytical techniques. In this study, catalysts with zeolite structure (Zeolite HY and SAPO-37 silicoaluminophosphate) were synthesized and characterized, in order to be screened up for the thermal degradation of high density polyethylene (HDPE). Catalytical activity was evaluated for these materiais using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). Kinetic parameters related to the HDPE thermal degradation process with and without catalyst were calculated employing the multiple heating rate integral method proposed by Flynn and Wall as well by using Vyazovkin (Model Free Kinetics). AII the evolved products were analyzed using a TG/DTA-GC/MS simul and coupled system. The data showed a positive catalytic activity for the zeolite structure materials.

In this thesis, yearly performance of the solar adsorption cooling system which is proposed to be installed to a residential building in Antalya is theoretically investigated in detail. Firstly, thermodynamic designs of the adsorption cooling cycle for three different types of cycles which are intermittent, heat recovery and heat &amp / mass recovery cycles are presented. Secondly, adsorption characteristics of three adsorbent/adsorbate pairs which are zeolite-water, silica gel-water and activated carbon-methanol are given. Following this, load side (i.e., building) of the system is designed and parameters that should be considered in building design are presented. Then, solar-thermal cooling system design methodology with an emphasis on solar fraction is presented. In addition, system parameters effecting the performance of the adsorption cooling system are analyzed and results are presented. Finally, economic analysis is done in order to understand the economic feasibility of the solar-thermal cooling systems compared to conventional cooling systems. TRNSYS is used for the yearly simulations and an integrated model of the overall system is developed in TRNSYS. Since energy consumption and performance investigations of environment-dependent systems such as building HVAC, refrigeration systems and solar collectors usually require weather information, typical meteorological year (TMY) data for Antalya is also generated in order to be used in the analysis of the system parameters.

Growing need for application of electronics at temperatures beyond their rated limit, (usually > 150 °C) and the non availability of high temperature compatible electronics necessitates thermal management solutions that should be compact, scalable, reliable and be able to work in environments characterized by high temperature (150 -250 °C), mechanical shock and vibrations. In this backdrop the proposed research aims at realization of an adsorption cooling system for evaporator temperatures in the range of 140 °C-150 °C, and condenser temperature in the range of 160 °C-200 °C. Adsorption cooling systems have few moving parts (hence less maintenance issues), and the use of Thermo-Electric (TE) devices to regenerate heat of adsorption in between adsorbent beds enhances the compactness and efficiency of the overall 'ThermoElectric-Adsorption' (TEA) system. The work presented identifies the challenges involved and respective solutions for high temperature application. An experimental set up was fabricated to demonstrate system operation and mathematical models developed to benchmark experimental results. Also, it should be noted that TEA system comprises TE and adsorption chillers. A TE device can be a compact cooler in its own right. Hence a comparison of the performance of TEA and TE cooling systems has also been presented.

The main theme of this dissertation is to engineer nanoporous materials and nanostructured surfaces for applications in gas separation membranes. Tunable methods have been developed to create inorganic hydroxide nanostructures on zeolite surfaces, and used to control the inorganic/polymer interfacial morphology in zeolite/polymer composite membranes. The study of the structure-property relationships in this material system showed that appropriate tuning of the surface modification methods leads to quite promising structural and permeation properties of the membranes made with the modified zeolites. First, a facile solvothermal deposition process was developed to prepare roughened inorganic nanostructures on zeolite pure silica MFI crystal surfaces. The functionalized zeolite crystals resulted in high-quality ̒mixed matrix̕ membranes, wherein the zeolite crystals were well-adhered to the polymeric matrix. Substantially enhanced gas separation characteristics were observed in mixed matrix membranes containing solvothermally modified MFI crystals. Gas permeation measurements on membranes containing nonporous uncalcined MFI revealed that the performance enhancements were due to significantly enhanced MFI-polymer adhesion and distribution of the MFI crystals. Solvothermal deposition of inorganic nanostructures was successfully applied to aluminosilicate LTA surfaces. Solvothermal treatment of LTA was tuned to deposit smaller/finer Mg(OH)₂ nanostructures, resulting in a more highly roughened zeolite surface. Characterization of particles and mixed matrix membranes revealed that the solvothermally surface-treated LTA particles were promising for application in mixed matrix membranes. Zeolite LTA materials with highly roughened surfaces were also successfully prepared by a new method: the ion-exchange-induced growth of Mg(OH)₂ nanostructures using the zeolite as the source of the Mg²⁺ ions. The size/shape of the inorganic nanostructures was tuned by adjusting several parameters such as the pH of the reagent solution and the amount of magnesium in the substrates and systematic modification of reaction conditions allowed generation of a good candidate for application in mixed matrix membranes. Zeolite/polymer adhesion properties in mixed matrix membranes were improved after the surface treatment compared to the untreated bare LTA. Surface modified zeolite 5A/6FDA-DAM mixed matrix membranes showed significant enhancement in CO₂ permeability with slight increases in CO₂/CH₄ selectivity as compared to the pure polymer membrane. The CO₂/CH₄ selectivity of the membrane containing surface treated zeolite 5A was much higher than that of membrane with untreated zeolite 5A. In addition, the use of metal organic framework (MOF) materials has been explored in mixed matrix membrane applications. ZIF-90 crystals with submicron and 2-μm sizes were successfully synthesized by a nonsolvent induced crystallization technique. Structural investigation revealed that the ZIF-90 particles synthesized by this method had high crystallinity, microporosity and thermal stability. The ZIF-90 particles showed good adhesion with polymers in mixed matrix membranes without any compatibilization. A significant increase in CO₂ permeability was observed without sacrificing CO₂/CH₄ selectivity when Ultem® and Matrimd® were used as the polymer matrix. In contrast, mixed matrix membranes with the highly permeable polymer 6FDA-DAM showed substantial enhancement in both permeability and selectivity, as the transport properties of the two phases were more closely matched.