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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Integrated Thermal Energy Systems : A Case Study of Nya Studenternas IP and Uppsala University Hospital

Nielsen, Freja, Bäckelie, Mika, Lindén, Thomas, Pålsson, Emma January 2016 (has links)
The aim of this project is to evaluate the possibility to integrate, in terms of energy, the future Nya Studenternas IP and Uppsala University Hospital. The focus is on integration of thermal energy solutions. To cover the cooling demand a seasonal snow storage and the use of cooling machines is studied. For the heat demand a joint heat storage is investigated which is heated partly with the excess heat from cooling machines. The environmental impact in terms of CO2 emissions is investigated. A conclusion drawn from the project is that the use of district heating and cooling of Nya Studenternas IP and the Uppsala University Hospital could be reduced in several ways by integrating the energy systems of the two facilities. For instance, with the support of a seasonal snow storage and cooling machines for cooling, and heat obtained from the cooling machines for heating, the emissions of CO2 could be reduced with 36% based on a Nordic electricity mixture. Out of the suggested integrated energy solutions the most efficient when it comes to reducing CO2 emissions is cooling and heating through cooling machines with a capacity of reducing the CO2 emissions of 20.6 %.
72

NITROGEN FIXATION AND THE FATE AND TURNOVER OF CARBON FIXED THROUGH HYDROGEN-COUPLED CARBON DIOXIDE FIXATION IN SOYBEANS

Graham, Amanda 31 January 2013 (has links)
Global production of soybeans continues to increase, reflecting the value of soybeans in food products, soil amendments, and petroleum replacements. While the N2O aspect of the legume greenhouse gas (GHG) budget has been given substantial, and mostly negative, attention, the CO2 side needs to be explored. During nitrogen fixation, hydrogen is produced. As a result of hydrogen-coupled CO2 fixation, legume soils have the ability to increase the amount of atmospheric carbon fixed into the soil. However, the amount and fate of this fixed carbon has yet to be determined. Therefore, two experiments were conducted. The first experiment explored the methods of 13C labeling of four soil treatments over a period of 28 days. Results showed that most of this carbon uptake was through biotic processes, and that the pattern of carbon uptake was similar for all four soil treatments. The ideal labeling time for both ‘root’ and ‘nodule’ soil was determined to be between 7 and 14 days. The second experiment incubated four 13C labeled soil treatments in a continuous soybean field for 11 months. Throughout this time, bags of soil were removed and separated into three soil organic matter (SOM) fractions; the microbial biomass fraction (MBF), the light fraction (LF), and the acid stable fraction (ASF). These fractions were then measured for δ13C, providing a time series showing carbon movement through the soil which enabled an estimation of the MRT of fixed carbon in the soil. Results showed that the MBF was responsible for the initial flux of carbon uptake in all soil treatments, and that the ‘nodule + H2’ MBF continued to fix carbon at the end of the 11 months. While the LF was not ideal at representing the intermediate SOM pool, the ASF did increase in enrichment at the end of the experiment, showing the movement of newly fixed carbon into long-term carbon storage. Therefore, hydrogen-coupled CO2 fixation does contribute to long-term carbon storage in legume soils, however, longer study times with focus on different legume plants and soil types are required to determine the mean residence time (MRT) of fixed carbon in the ASF. / Thesis (Master, Geography) -- Queen's University, 2013-01-30 09:28:01.899
73

Reactive transport modeling of CO2 through cementitious materials under CO2 geological storage conditions / Modélisation de la pénétration du CO2 dans les matériaux cimentaires dans le contexte du stockage du CO2

Shen, Jiyun 12 March 2013 (has links)
Un modèle de transport réactif est proposé pour simuler la réactivité des matériaux à base de ciment en contact avec une saumure saturée en CO2 et/ou le CO2 supercritique (CO2sc) dans les conditions de stockage géologique du CO2. Un code a été développé pour résoudre simultanément le transport et la chimie par une approche globale couplée, compte tenu de l'effet de la température et de la pression. La variabilité des propriétés du CO2sc avec la pression et la température, telles que la solubilité dans l'eau, la densité et la viscosité sont pris en compte. On suppose que tous les processus chimiques sont en équilibre thermodynamique. Les réactions de dissolution et de précipitation de la portlandite (CH) et de calcite (CC) sont décrites par des lois d'action de masse et des seuils de produit d'activité ioniques. Une cinétique de dissolution de CH est introduite pour faciliter la convergence numérique. La définition d'une variable principale permet de capturer la précipitation et la dissolution des phases solides à base de calcium. Une généralisation de la loi d'action de masse est développée et appliquée aux silicates de calcium hydratés (CSH) pour tenir compte de la variation continue (diminution) du rapport Ca/Si au cours de la dissolution des CSH. Les variations de porosité et de la microstructure induites par les réactions de précipitation et de dissolution sont également prises en compte. Le couplage entre le transport et la chimie est modélisé par cinq équations de bilan de masse écrites pour chaque atome (Ca, Si, C, K, Cl), ainsi que par une équation de conservation de la masse totale et celle de la charge électrique. Les lois de Darcy et de Nernst-Planck sont utilisées pour décrire le transport de masse et d'ions. Les propriétés de transport dépendent du degré de saturation et de la porosité. Le modèle est implémenté dans le code de volumes finis, Bil. Les principes de cette méthode et l'approche de modélisation sont discutés et illustrés sur un exemple simple. Ce modèle est en mesure de simuler les processus de carbonatation des matériaux à base de ciment, dans des conditions à la fois saturés et insaturés, dans une large plage de concentration de CO2, de température et de pression. Plusieurs expériences, rapportées dans la littérature, sont simulées en utilisant divers types de conditions aux limites: (i) solutions saturées ou non en CO2 et carbonate de calcium, (ii) gas supercritique de CO2. Les prédictions sont comparées avec les observations expérimentales. Certains phénomènes observés expérimentalement peuvent être également expliqués par le modèle / A reactive transport model is proposed to simulate the reactivity of cement based material in contact with CO2-saturated brine and supercritical CO2 (scCO2) under CO2 geological storage conditions. This code is developed to solve simultaneously transport and chemistry by a global coupled approach, considering the effect of temperature and pressure. The variability of scCO2 properties with pressure and temperature, such as solubility in water, density and viscosity are taken into account. It is assumed that all chemical processes are in thermodynamical equilibrium. Dissolution and precipitation reactions for portlandite (CH) and calcite (CC) are described by mass action laws and threshold of ion activity products in order to account for complete dissolved minerals. A chemical kinetics for the dissolution and precipitation of CH and CC is introduced to facilitate numerical convergence. One properly chosen variable is able to capture the precipitation and dissolution of the relevant phase. A generalization of the mass action law is developed and applied to calcium silicate hydrates (C-S-H) to take into account the continuous variation (decrease) of the Ca/Si ratio during the dissolution reaction of C-S-H. The changes in porosity and microstructure induced by the precipitation and dissolution reactions are also taken into account. Couplings between transport equations and chemical reactions are treated thanks to five mass balance equations written for each atom (Ca, Si, C, K, Cl) as well as one equation for charge balance and one for the total mass. Ion transport is described by using the Nernst-Plank equation as well as advection, while gas and liquid mass flows are governed by advection. Effect of the microstructure and saturation change during carbonation to transport properties is also considered. The model is implemented within a finite-volume code, Bil. Principles of this method and modeling approach are discussed and illustrated with the help of a simple example. This model, with all the efforts above, is able to simulate the carbonation processes for cement based materials, at both saturated and unsaturated conditions, in a wide CO2 concentration, temperature and pressure range. Several sets of experiments, including sandstone-like conditions, limestone-like conditions, supercritical CO2 boundary and unsaturated conditions reported in the literature are simulated. Good predictions are provided by the code when compared with experimental observations. Some experimental observed phenomena are also explained by the model in terms of calcite precipitation front, CH dissolution front, porosity profile, etc
74

[en] DEVELOPMENT OF OIL FIELDS CONSIDERING THE PRESENCE OF CO2: THEORETICAL FRAMEWORK AND CASE STUDY / [pt] PRESENÇA DE CO2 EM PROJETOS DE DESENVOLVIMENTO DE CAMPOS DE PETRÓLEO: ARCABOUÇO TEÓRICO E ESTUDO DE CASO

JAIME TURAZZI NAVEIRO 01 February 2013 (has links)
[pt] A degradação do meio ambiente está no topo da agenda de países e empresas. O foco principal é a redução das emissões de gases causadores do efeito estufa, sendo CO2 o maior contribuinte. O consumo elevado de combustíveis fósseis está criando um efeito irreversível no planeta. De forma a contrabalancear seus impactos ambientais, surge o segmento de projetos de captura e sequestro de carbono. O maior entrave seu para crescimento é econômico, daí o uso de CO2 para recuperação avançada de óleo, alavancando sua implementação. Esta dissertação avalia duas estratégias distintas de desenvolvimento de um campo de petróleo offshore, uma através da injeção de água e outra por recuperação avançada com injeção de CO2 (EOR CO2 – enhanced oil recovery) a partir de fonte antropogência. Os maiores desafios técnicos para aplicação de EOR CO2 em ambiente offshore são examinados, mostrando o arcabouço teórico, melhores práticas e soluções ainda não desenvolvidas, em áreas como: gerenciamento de reservatórios, engenharia de poços e plantas de processo, além de captura e transporte de CO2. Em seguida, a viabilidade econômica de ambos os métodos de recuperação são comparados, com pequena vantagem o caso EOR. Entretanto, devido às incertezas de sucesso do método e sua sensibilidade ao preço de importação de CO2, a gama de resultados pode alterar o processo decisório. Um balanço de carbono também é realizado, mostrando a redução esperada de sua concentração na atmosfera ao se selecionar o método de EOR CO2. Ainda, a aplicabilidade de créditos de carbono é discutida, e seu impacto econômico quantificado. Finalmente, há um longo caminho a se percorrer para ampla utilização de projetos EOR com CO2 antropogênico em ambiente offshore. Ao apontar os maiores desafios e entraves a serem superados, incluindo técnicos, comerciais e regulatórios, ao apresentar modelo econômico, e acima de tudo, ao mostrar sua atratividade, esta dissertação tem por objetivo reduzir esta distância. / [en] Environmental issues are on top of governments and companies’ agendas. The main focus is on global warming and means to reduce greenhouse gases, being carbon dioxide the main contributor. The consumption of fossil fuels is creating an irreversible effect on the planet, and it is expected to continue for years to come. In order to offset its usage are the emerging carbon capture and storage (CCS) projects. Their main obstacle is economical, and that’s where enhanced oil recovery through CO2 can help. This dissertation assesses the development options of an offshore Brazilian discovery, by comparing water injection method with carbon dioxide enhanced oil recovery (EOR CO2) imported from an anthropogenic onshore source. The main EOR CO2 technical challenges for offshore application are examined, detailing field proven and yet to be developed solutions, from reservoir management, wells engineering to the production unit, passing through CO2 acquisition and transportation. Next, economical feasibility of both methods are compared, with a slight advantage for EOR on the base case. Nevertheless, due to high uncertainties in method success prior to development and commitment, and also to carbon dioxide import prices, the range of results can shift the decision making, and such sensitivity analysis is also presented. A carbon inventory is also made, showing the net positive balance of selecting EOR CO2, which reduces the component’s concentration in the atmosphere. Finally, the applicability of carbon credits is discussed and its economical impact quantified. There is still a long way to go for the widespread utilization of anthropogenic EOR CO2 in offshore projects. By pointing out the main challenges to be addressed, including technical, commercial and regulatory, by presenting an economical model comprising environmental aspects, and most of all, showing its attractiveness, this dissertation aims to reduce this gap.
75

CO2-Variation over the Baltic Sea

Åström, Gustav January 2007 (has links)
<p>The increasing levels of the greenhouse gas carbon dioxide (CO2) in the Earths atmosphere, caused by human release of CO2, has made it desirable to understand the factors determining the CO2-variation because of CO2’s warming effect on the Earths temperature which will change the premises of all life on earth.</p><p>The purpose of this investigation is to understand the effects of the largest factors of influence on the CO2-concentration - like sea, vegetation and anthropogenic outlets - in the Baltic Sea region, and possible surprises from the results. To be able to do this only from CO2-measurements some assumptions have to be done as starting point. Such are that, besides from the yearly trend of the CO2-concentration and the variation of oceanic influence, monthly variation only is caused by vegetation and that the yearly offset in CO2-levels only is affected by anthropogenic outlets. These factors are together called the local season and will be used for evaluation of the CO2-values for each site. This analysis is done for eight sites surrounding the Baltic Sea region and is compared with results from the site of Östergarnsholm, an island in the Baltic Sea east of Gotland.</p><p>The results show that stations with high vegetational influence has high amplitudes for the local season compared to sites more influenced by sea. This also makes the amplitude to be connected with latitude since sites with longer growing season is surrounded by higher density of vegetation. The minimum for the local season is also dependent on the growing season, since it occurs when the vegetational consumption is largest. Peaks in the local season can be seen in connection with the maximum decay of the natural vegetation in the early winter months, and with the planting and harvest season for agricultural land. Considering the effect from anthropogenic influence a clear connection in the offset of the local season can be seen, with higher offsets for sites of higher anthropogenic influence and vice versa. Anthropogenic influence also seems to give raised values in summer for the local season, indicating that the variation of the local season cannot be simply connected to only vegetational influence. For variability, higher values in the summer months are seen for the anthropogenic sites, while in winter the variability is more similar for all sites. This might be connected with a higher degree of local influence during summers, which for anthropogenic stations leads to high variability due to inhomogenous surroundings.</p><p>For Östergarnsholm we get higher amplitude for the local season than expected, this is partly due to unrepresentatively high amplitudes for the seasons used, but also probably to some degree of underestimation of the vegetational influence. Due to correction of the offset it was not possible to draw any conclusions from this factor, but rather give suggestions of what the correction should be. When analysing the local season for different source areas by WD-classification we see the surprising property that the sector that should be most influenced by land, due to higher values in summer, has a lower amplitude than the sector most influenced by sea. Since it was suggested that anthropogenic influence gives raised values in summer this was suggested as an explanation.</p>
76

Effect of flue gas impurities on the process of injection and storage of carbon dioxide in depleted gas reservoirs

Nogueira de Mago, Marjorie Carolina 01 November 2005 (has links)
Previous experiments - injecting pure CO2 into carbonate cores - showed that the process is a win-win technology, sequestrating CO2 while recovering a significant amount of hitherto unrecoverable natural gas that could help defray the cost of CO2 sequestration. In this thesis, I report my findings on the effect of flue gas ??impurities?? on the displacement of natural gas during CO2 sequestration, and results on unconfined compressive strength (UCS) tests to carbonate samples. In displacement experiments, corefloods were conducted at 1,500 psig and 70??C, in which flue gas was injected into an Austin chalk core containing initially methane. Two types of flue gases were injected: dehydrated flue gas with 13.574 mole% CO2 (Gas A), and treated flue gas (N2, O2 and water removed) with 99.433 mole% CO2 (Gas B). The main results of this study are as follows. First, the dispersion coefficient increases with concentration of ??impurities??. Gas A exhibits the largest dispersion coefficients, 0.18-0.25 cm2/min, compared to 0.13-0.15 cm2/min for Gas B, and 0.15 cm2/min for pure CO2. Second, recovery of methane at breakthrough is relatively high, ranging from 86% OGIP for pure CO2, 74-90% OGIP for Gas B, and 79-81% for Gas A. Lastly, injection of Gas A would sequester the least amount of CO2 as it contains about 80 mole% nitrogen. From the view point of sequestration, Gas A would be least desirable while Gas B appears to be the most desirable as separation cost would probably be cheaper than that for pure CO2 with similar gas recovery. For UCS tests, corefloods were conducted at 1,700 psig and 65??C in such a way that the cell throughput of CO2 simulates near-wellbore throughput. This was achieved through increasing the injection rate and time of injection. Corefloods were followed by porosity measurement and UCS tests. Main results are presented as follows. First, the UCS of the rock was reduced by approximately 30% of its original value as a result of the dissolution process. Second, porosity profiles of rock samples increased up to 2.5% after corefloods. UCS test results indicate that CO2 injection will cause weakening of near-wellbore formation rock.
77

CO2-Variation over the Baltic Sea

Åström, Gustav January 2007 (has links)
The increasing levels of the greenhouse gas carbon dioxide (CO2) in the Earths atmosphere, caused by human release of CO2, has made it desirable to understand the factors determining the CO2-variation because of CO2’s warming effect on the Earths temperature which will change the premises of all life on earth. The purpose of this investigation is to understand the effects of the largest factors of influence on the CO2-concentration - like sea, vegetation and anthropogenic outlets - in the Baltic Sea region, and possible surprises from the results. To be able to do this only from CO2-measurements some assumptions have to be done as starting point. Such are that, besides from the yearly trend of the CO2-concentration and the variation of oceanic influence, monthly variation only is caused by vegetation and that the yearly offset in CO2-levels only is affected by anthropogenic outlets. These factors are together called the local season and will be used for evaluation of the CO2-values for each site. This analysis is done for eight sites surrounding the Baltic Sea region and is compared with results from the site of Östergarnsholm, an island in the Baltic Sea east of Gotland. The results show that stations with high vegetational influence has high amplitudes for the local season compared to sites more influenced by sea. This also makes the amplitude to be connected with latitude since sites with longer growing season is surrounded by higher density of vegetation. The minimum for the local season is also dependent on the growing season, since it occurs when the vegetational consumption is largest. Peaks in the local season can be seen in connection with the maximum decay of the natural vegetation in the early winter months, and with the planting and harvest season for agricultural land. Considering the effect from anthropogenic influence a clear connection in the offset of the local season can be seen, with higher offsets for sites of higher anthropogenic influence and vice versa. Anthropogenic influence also seems to give raised values in summer for the local season, indicating that the variation of the local season cannot be simply connected to only vegetational influence. For variability, higher values in the summer months are seen for the anthropogenic sites, while in winter the variability is more similar for all sites. This might be connected with a higher degree of local influence during summers, which for anthropogenic stations leads to high variability due to inhomogenous surroundings. For Östergarnsholm we get higher amplitude for the local season than expected, this is partly due to unrepresentatively high amplitudes for the seasons used, but also probably to some degree of underestimation of the vegetational influence. Due to correction of the offset it was not possible to draw any conclusions from this factor, but rather give suggestions of what the correction should be. When analysing the local season for different source areas by WD-classification we see the surprising property that the sector that should be most influenced by land, due to higher values in summer, has a lower amplitude than the sector most influenced by sea. Since it was suggested that anthropogenic influence gives raised values in summer this was suggested as an explanation.
78

CO2 emission in China and Europe : compare China and Europe

Wang, Fengyuan, Shi, Rui January 1989 (has links)
Realize the situation about CO2 emission in Europe and China. Find out which reasons caused the CO2 emission will be changed. We did the data collection: CO2 emissions from China and EU. Energy consumption (include the total, electricity and transportation) and energy structure. Increased CO2 emission caused by Global warming. The CO2 emission increased with fossil-fuel use increased. China almost used of fossil energy, in 2004, domestic use for coal achieve to 67.7% of the total energy consumption. In 2010, the coal supply account for 48% of the world; the coal supply in 2000 to 2009 increased 85.5%. The CO2 emissions in 2009 is 6803.92 mil-tones, increased 13.32% than 2008, No. 1 of world. EU energy structure is keep changed, the rate of utilization for traditional fossil-fuel was gradually reduced. In 2010, the EU coal supply 8% of the world, 2000-2009 presents negative growth (3.8%). The CO2 emissions in 2009 were 4310.3 mil-tones, more than 2008 years to reduce 6.9%. CO2 emission based on energy consumption; Energy consumption is supply a variety of services to people. We must consider with population. China’s CO2/per capita less than average level in world, and lower than most EU countries.   China and EU are planning for future energy structure (reduce the use of fossil-fuel and increase renewable energy construction), that means up to energy saving and emission reduction purpose. The emission reduction of focus is to change the energy structure, reduce fossil-fuel use. China predicting the coal utilization rate under 60% of the total energy consumption. Thus, by 2020, forecast reducing 40-45% CO2 emission based on 1995. EU energy structure better than china, while they planning energy saving reach 20% at 2020, and improve the renewable energy use. By 2020, EU-27 forecast reducing 20% CO2 emission based on 1990 CO2 emission.
79

Synthèse et caractérisation d'électrocatalyseurs à base de pyridine pour la réduction du CO2

Agullo, Julia 12 1900 (has links) (PDF)
Lors de ce projet, la pyridine a été utilisée comme base d'électrocatalyseurs pour la réduction électrochimique du CO2. La réduction électrochimique du cation pyridinium et de ses dérivés aminés et/ou méthylés a été étudiée sur une électrode de Pt et de carbone vitreux en absence et en présence de CO2. Le comportement de ce cation a été analysé par différentes techniques spectroscopiques et électrochimiques. Les cations à base d'ion pyridinium peuvent se trouver, soit en solution, soit immobilisés par différentes méthodes à la surface d'une électrode pour former ainsi un nouveau type d'électrocatalyseur. L'ion pyridinium et ses dérivés aminés en solution ont montré un effet catalytique pour la réduction du CO2 sur le Pt et sur le carbone vitreux. Lorsque l'azote du cycle aromatique de la pyridine est bloqué avec un groupement méthyle, l'activité catalytique reste présente sur le carbone vitreux mais disparaît sur le Pt. La surface joue un rôle déterminant et entraîne un mécanisme différent pour les deux électrodes. L'ion N-méthyle-3-aminopyridinium a montré les meilleurs résultats électrochimiques et laisse penser que des carbènes interviennent dans le mécanisme d'interactions entre la pyridine et le CO2 sur le carbone vitreux. Les électrodes de carbone vitreux et Pt ont été fonctionnalisées avec la pyridine par oxydation de la 3-aminopyridine. La méthode par oxydation a permis d'immobiliser la pyridine par un lien substrat-NH-C. La caractérisation des électrodes modifiées par spectroscopie du photoélectron X (XPS) a révélé un taux de presque 20% at. en azote. Les électrodes fonctionnalisées ont également été testées par voltampérométrie cyclique en absence et en présence de CO2. Aucun signal relatif à l'ion pyridinium n'a été décelé sur le Pt contrairement au carbone vitreux indiquant à nouveau un comportement différent selon le substrat. Dans les deux cas, l'effet catalytique sur la réduction du CO2 n'a pas pu être démontré. La pyridine a également été immobilisée à la surface du carbone vitreux par un lien covalent C-C grâce à la réduction du cation 3-diazopyridinium généré in situ. La caractérisation de la couche greffée a montré qu'une augmentation du temps de diazotation avant l'électrogreffage ou que la présence d'un excès de nitrite de sodium diminuait l'efficacité du greffage de la pyridine. Lorsque la concentration en amine ou le potentiel cathodique ou le temps de réduction appliqué devient plus important, les propriétés bloquantes et le taux de recouvrement en molécules de la couche greffée sont augmentés. La présence de pyridine a été confirmée par des analyses XPS. La valeur de son pKa apparent a pu être estimée à 5, ce qui est proche de celle du couple pyridine/pyridinium en solution. L'ion pyridinium immobilisé s'est révélé électroactif dans des solutions dont la valeur du pH est inférieure à celle de son pKa. Cependant dès que l'ion pyridinium est réduit, il n'est pas régénéré et devient inactif. De plus, comme pour le cas de l'immobilisation par oxydation, aucun effet catalytique n'a été discerné pour la réduction du CO2. Dans l'optique de réduire le CO2 avec un impact sur l'environnement le plus faible possible, l'utilisation de l'énergie solaire et de matériau de type semiconducteur a été envisagée. Des modifications de surface à partir de particules de Pt et Cu ont été réalisées sur le p-InP et ont montré un effet positif sur la réduction des protons et du CO2, respectivement. Malheureusement, la trop forte réactivité du p-InP, en particulier son oxydation spontanée, n'a pas permis de tester la pyridine comme électrocatalyseur pour la photoréduction du CO2. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : pyridine, réduction électrochimique du CO2, électrocatalyseur, carbène, carbone vitreux, platine, p-InP, électrogreffage, diazotation, sel de diazonium, oxydation des amines.
80

Synthesis and Characterization of Iso-Reticular Metal-Organic Frameworks and Their Applications for Gas Separations

Yoo, Yeonshick 2010 August 1900 (has links)
Nanoporous metal-organic frameworks (MOFs) have attracted tremendous interest due to their potential applications in gas-storage, gas separation, gas sensing, and catalysis. MOFs consist of metal-oxygen polyhedera interconnected with a variety of organic linker molecules, resulting in tailored nanoporous materials. With a judicious choice of organic linker groups, it is possible to fine-tune size, shape, and chemical functionality of the cavities and the internal surfaces. This unique structural feature offers unprecedented opportunities in small-molecule separations as well as chiral separations and catalysis. Prototypical iso-reticular metal-organic frameworks (IRMOFs) have been extensively studied among MOFs due to the simplicity of their synthesis and the variety of their potential applications. IRMOFs are a specific series of metal-organic frameworks developed by Yaghi and his coworkers. All IRMOFs are composed of oxygen-centered Zn4O tetrahedra interconnected with dicarboxylate linkers, forming a cubic type three dimensional (3D) porous network with high surface area. Despite a great deal of research in the synthesis and characterization of MOFs, there have been relatively few reports on the development of their applications, such as the fabrication of MOF thin films and membranes for gas separations. This is mainly due to the challenges associated with relatively difficult heterogeneous nucleation (seeding) and growth of MOFs on supports, and crack formation compared to their counterparts. Thin films and membranes of MOFs have great potentials for applications in membranebased gas separations, reactors, chemical sensors, and nonlinear optical devices. In this dissertation, the fabrication of IRMOF-1 membrane using a novel seeding method and its gas diffusion properties has been demonstrated. Introduction of the new seeding method for MOFs using microwaves resulted in well inter-grown IRMOF membranes showing Knudsen type transport of small gases through its pore. The heteroepitaxial growth of one IRMOF on another produced multi-layered IRMOF membranes. In addition, postsynthetic modification (PSM) of IRMOFs created functionalized membranes with enhanced stability against water as well as reduced crack formation during membrane fabrication. Lastly, hierarchical IRMOFs with improved CO2 adsorption properties were synthesized via PSM with cyanuric chloride.

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