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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.
31

Qualidade higiênico-sanitária e quimica do leite e avaliação de impactos ambientais e sociais, após a utilização do kit embrapa de ordenha manual® para caprinos leiteiros / HYGIENIC-SANITARY AND CHEMYSTRY QUALITY OF THE MILK, AND ENVIRONMENTAL AND SOCIAL IMPACTS, AFTER THE USE OF THE KIT EMBRAPA DE ORDENHA MANUAL® FOR DAIRY GOATS

Andrade, Patrícia Lopes January 2012 (has links)
ANDRADE, Patrícia Lopes. Qualidade higiênico-sanitária e quimica do leite e avaliação de impactos ambientais e sociais, após a utilização do kit embrapa de ordenha manual® para caprinos leiteiros. 2012. 74 f. Tese (doutorado em zootecnia)- Universidade Federal do Ceará, Fortaleza-CE, 2012. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-04-22T18:44:01Z No. of bitstreams: 1 2012_tese_plandrade.pdf: 1145709 bytes, checksum: d44b340ecf19cb05a3e501fce9ad0178 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-05-27T17:51:19Z (GMT) No. of bitstreams: 1 2012_tese_plandrade.pdf: 1145709 bytes, checksum: d44b340ecf19cb05a3e501fce9ad0178 (MD5) / Made available in DSpace on 2016-05-27T17:51:19Z (GMT). No. of bitstreams: 1 2012_tese_plandrade.pdf: 1145709 bytes, checksum: d44b340ecf19cb05a3e501fce9ad0178 (MD5) Previous issue date: 2012 / The northeastern region of Brazil has great potential for the production of goat milk, and the quality of the milk produced is important to ensure consumers a safe food supply from the nutritional and hygienic-sanitary standpoint. Goat milk has high nutritional value and has a wide acceptance, especially in poor communities, since it is an important protein source in the diet of these people. The free and daily distribution of the goat milk, through government programs, aims to reduce nutritional deficiencies with priority given to children, pregnant women and nursing mothers. The goal of this study was to evaluate the effect of the Kit Embrapa de Ordenha Manual® for dairy goats in family farming, located in three regions of northeastern Brazil. This effect was evaluated in samples of goat milk on the composition, somatic cell count (SCC) and total bacterial count (TBC), and also the effect of SCC on the components, by correlation of the data. In parallel, we assessed the environmental and social impacts of the Kit through Sistema Ambitec-Agro. The Kit Embrapa de Ordenha Manual® was developed with the purpose of safe milk production through a low-cost technology that is available to family farmers, who are responsible for much of the production of goat milk in Brazil. Its validation in properties of Paraiba, Rio Grande do Norte and Ceará brought positive results, as the average of TBC decreased 72% and the characteristics of milk composition were preserved. The evaluation of SCC effect on the milk components showed that there was a decrease in the percentage of lactose in milk as SCC increased. Among the samples analyzed, 64% had counts exceeding 1.000.000 CCS/mL. This highlights the need for the implementation of hygiene practices on the milking properties evaluated. The social and environmental impact was also positive, with average values of 1.07 and 0.9 in the ex post evaluation indexes for Environmental and Social Impact, respectively, showing the potential of this technology as part of a set of attitudes capable of improving the quality of goat milk produced in Brazil, as well as of providing gains to producers. / A região nordeste do Brasil tem grande potencial para a produção de leite de cabra, e a qualidade do leite produzido é importante para garantir a oferta de um alimento seguro do ponto de vista nutricional e higiênico sanitário aos consumidores. O leite de cabra tem alto valor nutricional e possui grande aceitação, especialmente em comunidades carentes, uma vez que constitui importante fonte proteica de alta qualidade na dieta dessas pessoas. A distribuição gratuita e diária do leite de cabra, por meio de programas governamentais, tem o objetivo de reduzir deficiências nutricionais com prioridade para as crianças, as gestantes e as nutrizes. O Kit Embrapa de Ordenha Manual® foi desenvolvido com o propósito de contribuir para a produção segura do leite, através de uma tecnologia de baixo custo, ao alcance dos produtores familiares, os quais são responsáveis por grande parte da produção de leite de cabra no Brasil. O objetivo deste trabalho foi avaliar o efeito do Kit Embrapa de Ordenha Manual® para caprinos leiteiros em propriedades de agricultura familiar, localizadas em três regiões do nordeste Brasileiro. Durante o período de maio de 2010 a fevereiro de 2011, foram colhidas amostras de leite de cabra provenientes de rebanhos dos Estados do Ceará, Paraíba e Rio Grande do Norte para determinação da composição, contagem de células somáticas (CCS) e contagem bacteriana total (CTB). Avaliou-se também os impactos ambientais e sociais do Kit através do Sistema Ambitec-Agro. Após a implantação do Kit nas propriedades estudadas, observou-se uma diminuição média de 72,1% da CTB e preservação das características de composição do leite. A avaliação do efeito da CCS sobre os componentes mostrou que houve um decréscimo da porcentagem de lactose do leite conforme aumentou a CCS. Dentre as amostras analisadas, 64% apresentavam contagens superiores a 1.000.000 CCS/mL, antes da adoção do Kit, o que evidenciou a necessidade da implantação das Boas Práticas de ordenha nas propriedades avaliadas. A avaliação de impacto social e ambiental foi positiva, apresentando valores médios de 1,07 e 0,9 na avaliação ex-post para os índices de impacto Ambiental e Social, respectivamente, mostrando o potencial desta tecnologia como parte de um conjunto de atitudes capazes de melhorar a qualidade do leite de cabra produzido no Brasil, assim como proporcionar ganhos aos produtores.
32

High Pressure Oxy-fired (HiPrOx) Direct Contact Steam Generation (DCSG) for Steam Assisted Gravity Drainage (SAGD) Application

Cairns, Paul-Emanuel January 2013 (has links)
Production in Canada’s oil sands has been increasing, with a projected rate of 4.5 million barrels per day by 2025. Two production techniques are currently used, mining and in-situ, with the latter projected to constitute ~57% of all production by that time. Although in-situ extraction methods such as Steam Assisted Gravity Drainage (SAGD) are less invasive than mining, they result in more greenhouse gas (GHG) emissions per barrel and require large amounts of water that must be treated and recycled with a make-up water requirement of about 10%. CanmetENERGY is developing a steam generation technology called the High Pressure Oxy-fired Direct Contact Steam Generator (HiPrOx/DCSG, or DCSG for short) that will reduce these water requirements and sequester GHGs. This study evaluates the technical feasibility of this technology using process simulations, bench-scale testing, and pilot-scale testing. At first, a method in which to integrate the DCSG into the SAGD process was presented and process modeling of expected system performance was undertaken. The process simulations indicated that DCSG decreased the energy intensity of SAGD by up to 7.6% compared to the base SAGD case without carbon capture and storage (CCS), and up to 12.0% compared to the base SAGD case with CCS. Bench-scale testing was then performed using a pressurized thermogravimetric analyzer (PTGA) in order to investigate the effects of increased pressure and high moisture environments on a Canadian lignite coal char’s reactivity. It was found that under reaction kinetic-controlled conditions at atmospheric pressure, the increased addition of steam led to a reduction in burning time. The findings may have resulted from the lower heat capacity and higher thermal conductivity of steam compared to CO2. At increased pressures, CO2 inhibited burnout due to its higher heat capacity, lower thermal conductivity, and its effect on C(O) concentrations on the particle surface. When steam was added, the inhibiting effects of CO2 were counteracted, resulting in burnout rates similar to pressurized O2/N2 environments. These preliminary results suggested that the technology was feasible at a bench-scale level. Conflicting literature between bench-scale and pilot-scale studies indicated that pilot-scale testing would be advantageous as a next step. At the pilot-scale, testing was performed using n-butanol, graphite slurry, and n-butanol/graphite slurry mixtures covering lower and upper ends in fuel reactivity. It was found that stable combustion was attainable, with high conversion efficiencies in all cases. With the n-butanol, it was possible to achieve low excess oxygen requirements, which minimizes corrosion issues and reduce energy requirements associated with oxygen generation. With graphite slurry, it was found that it was possible to sustain combustion in these high moisture environments and that high conversion was achieved as indicated by the undetectable levels of carbonaceous materials observed in downstream equipment. Overall, these studies indicate that DCSG is technically feasible from the perspectives of energy and combustion efficiencies as well as from a steam generation point of view. Future work includes the investigation of possible corrosion associated with the product gas, the effect of CO2 on bitumen production, the nature of the mineral melt formed by the deposition of the dissolved and suspended solids from the water in the combustor, and possible scaling issues in the steam generator and piping associated with mineral deposits from the dissolved and suspended solids in the produced water is recommended.
33

Potential att lagra koldioxid genom in situ-karbonatisering i Sundsvall och Örnsköldsvik

Öjebrandt, Anna January 2023 (has links)
Samhället står inför stora utmaningar för att lyckas nå målet i Parisavtalet om att begränsa den antropogena uppvärmningen till 1,5˚C samt det nationella klimatmålet om att uppnå netto-noll-utsläpp av växthusgaser senast år 2045. Geologisk lagring av koldioxid (CCS, Carbon Capture and Storage) lyfts fram som en nyckelåtgärd för att reducera koldioxidutsläppen och därigenom uppnå dessa mål. Totalt beräknas ca. 2700 CCS-projekt behövas år 2050, vilket är en signifikant ökning från dagens 27 anläggningar. Bio-CCS, eller BECCS (Bio-Energy with Carbon Capture and Storage) är en CCS-teknik där koldioxid som bildas som en industriell biprodukt fångas in och lagras. Koldioxiden kan till exempel fångas in vid förbränning av biomassa i massa- och pappersbruk. På senare år har en ny geologisk lagringsmetod utvecklats där man lagrar koldioxid genom att bilda stabila karbonatmineral in situ. In situ-karbonatisering utmanar i allra högsta grad den hittills dominerande lagringsmetoden där lagring av koldioxid sker i sedimentär berggrund. När koldioxid lagras i sedimentär berggrund tar det tusentals år för koldioxiden att bilda karbonatmineral, vilket kan jämföras med in situ-karbonatisering där det visat sig ta <2 år att uppnå samma resultat. Karbonatisering påskyndar en naturlig process som sker när kol lagras i marken och utnyttjar därmed bergartens befintliga egenskaper.  Ultramafisk och mafisk berggrund med högt innehåll av tvåvärt järn (Fe2+), kalcium (Ca2+) och magnesium (Mg2+), har visat sig vara lämpade för in situ-karbonatisering. Fram tills nu har potentialen för in situ-karbonatisering aldrig undersökts i Sverige. Detta arbete syftar därför till att karaktärisera mafiska bergarter baserat på deras teoretiska potential att lagra koldioxid genom in situ-karbonatisering, vilket gjorts genom att studera mineralogin och geokemin av olika bergarter från lokaliteter på Alnön, öster om Sundsvall och runt Nordingrå utanför Örnsköldsvik samt områden i närheten av Örnsköldsvik. Det här arbetet är en del av forskningsprojektet INSURANCE som finansieras av Energimyndigheten och syftar till att utvärdera potentialen för bio-CCS i den svenska berggrunden. Resultatet påvisade mineralogiska och geokemiska likheter mellan de provtagna områdena och basalt som visat sig vara lämplig för koldioxidlagring. En del av proverna uppvisar dock tecken på omvandling vilket är påverkar reaktionen negativt. Därför är det främst de lokaler som uppvisar låg omvandlingsgrad som rekommenderas för vidare undersökning. Proverna innehåller mineral som har potential att fungera för in situ-karbonatisering. Det behövs dock ytterligare undersökningar för hur dessa bergarter reagerar med koldioxiden i praktiken (karbonatiseringsexperiment) samt storleken/volymen på en eventuell lagringsplats. / Society faces major challenges to succeed in achieving the goal of the Paris Agreement to limit anthropogenic warming to 1.5°C and the national climate target of achieving zero net emissions of greenhouse gases by 2045. Geological storage of carbon dioxide (CCS, Carbon Capture and Storage) is highlighted as a key action in reducing carbon dioxide emissions and thereby achieve these goals. In total, approx. 2700 CCS projects are needed by 2050, which is a significant increase from today's 27 facilities. Bio-CCS, or BECCS (Bio-Energy with Carbon Capture and Storage) is a CCS technology where carbon dioxide formed as an industrial by-product is captured and stored. The carbon dioxide can, for example, be captured during the combustion of biomass in pulp and paper industries. In recent years, a new geological storage method has been developed where carbon dioxide is stored by forming stable carbonate minerals in situ. In situ carbonation is very much challenging the until now dominant storage method that stores carbon dioxide in sedimentary basins. When carbon dioxide is stored in sedimentary basins, it takes thousands of years for the carbon dioxide to form carbonate minerals, which can be compared to in situ carbonation where it has been shown to take <2 years to achieve the same result. Carbonation accelerates a natural process that occurs when carbon is stored in the soil, thereby utilizing the rock's existing properties. Ultramafic and mafic bedrock with a high content of divalent iron (Fe2+), calcium (Ca2+) and magnesium (Mg2+), have proven to be suitable for in situ carbonation. Until now, the potential for in situ carbonation has not been investigated in the Swedish bedrock. This work therefore aims to characterize mafic rocks based on their theoretical potential to store carbon dioxide through in situ carbonation, which has been done by studying the mineralogy and geochemistry of different rocks from localities on Alnön, east of Sundsvall and around Nordingrå outside Örnsköldsvik and areas near Örnsköldsvik. This work is part of the research project INSURANCE, which is funded by the Swedish Energy Agency and aims to evaluate the potential for bio-CCS in Sweden. The sampled areas show mineralogical and geochemical similarities to basalt which has been proven to be suitable for carbon dioxide storage. However, some of the samples show signs of alteration, which affects the reaction negatively. Therefore, it is mainly those localities that show a low alteration rate that are recommended for further investigation. The samples contain mineral that has the potential to function for in situ carbonation. However, further studies are needed on how these rocks react with carbon dioxide in practice (carbonation experiment) and to evaluate the size/volume of the possible storage site.
34

A Holistic Framework for Evaluating Gigatonne Scale Geological CO2 Storage in the Alberta Oil Sands: Physics, Policy, and Economics / Carbon Capture and Storage in the Alberta Oil Sands

Zhao, Yu Hao January 2023 (has links)
An increasing number of countries worldwide have made commitments in recent years to reduce emissions with the goal of limiting global temperature increases to 1.5-2 °C. Carbon capture and storage (CCS) is capable of significantly reducing anthropogenic carbon dioxide (CO2) emissions and is an important tool in the effort to mitigate climate change. The ability of CCS to sequester emissions at a large scale makes it suitable to particularly emission-intensive sectors, such as the oil and gas sector in Canada. Many factors must be considered holistically to ensure the long-term success of large-scale CCS, such as the availability of emission sources, the design of a CO2 transportation network, the availability and capacity of suitable storage sites, the long-term fate of the injected CO2, the economic viability of the system, and the overall policy environment. Previous studies have considered these factors in demonstrating the viability of CCS in Alberta but have not done so holistically. We take a holistic approach in designing a large-scale integrated CCS system which includes CO2 capture from a hub of 10 large oil sands emitters, transport via a pipeline network, and permanent sequestration in the Nisku and Wabamun saline formations. We use a logistic model to forecast long-term oil sands hydrocarbon production and annual emissions, and ensure that all of the capturable emissions can be stored safely without exceeding pressure limits by modeling the long-term pressure evolution. The injected CO2 will be fully trapped in 6100-11000 years without migrating past the minimum storage depth. We calculate the capital expenditures for the pipeline and injection well components of the system and show that the amount of funding required is reasonable under the umbrella of federal infrastructure funding. This provides a comprehensive framework to ensure the long-term success of future CCS projects. / Thesis / Master of Applied Science (MASc) / The global community has increasingly recognized the importance of greenhouse gas emission reductions in the effort to mitigate climate change. Carbon capture and storage (CCS) is a technology that, with widespread use at a large scale, has the potential to significantly reduce emissions. However, due to the high cost and lengthy time commitment required, many factors ranging from emission sources to storage capacity to financial considerations must be accounted for to ensure the success of a CCS system. Here, we show that a large-scale CCS system in Alberta is viable and the captured CO2 can be safely stored in the long term. This framework can be used to ensure the success of future CCS projects.
35

Assessment of the CO2 Storage Potential in the Unayzah Formation, Kingdom of Saudi Arabia

Corrales Guerrero, Miguel Angel 07 1900 (has links)
Owing to the excess of carbon dioxide emissions in the atmosphere, a transition to a neutral carbon economy is needed. In this framework, Carbon Capture and Storage (CCS), and Carbon Capture Utilization and Storage (CCUS) become essential areas of development. Sequestering CO2 into different geological media such as deep saline aquifers and hydrocarbon reservoirs reduces the net anthropogenic gas emissions. In 2020, the global CO2 emissions corresponded to 31.5 gigatons. In the case of Saudi Arabia, the Riyadh province emitted 45.8 megatons. This study aims to evaluate for the first time the CO2 storage potential of the Unayzah Formation in Saudi Arabia, identify the primary trapping mechanisms, and capture the effects of the highly heterogeneous reservoir. CO2 injection in geological media is challenging because of the complexity of the geological properties and the CO2 phase behavior at super-critical conditions. In the present evaluation, we constructed a geological model only with public domain data. Similarly, we obtained different scenarios of the model on account of the uncertainty in the geological parameters. Later on, we selected a base model representing a conservative scenario to perform high-resolution simulations to determine the dominant mechanisms influencing the storage efficiency. In the main analysis, we simulated continuous injection of CO2 for forty years followed by twenty years of monitoring. We tested the injectivity of the reservoir showing it is possible to inject 1 and 2 megatons in vertical and horizontal wells, respectively. Likewise, lower injection rates improved solubility and residual trapping. Residual trapping is dominant, and it could reach fifty percent, while solubility could reach up to fifteen percent of the total CO2 injected. Along with these scenarios, we performed an Uncertainty Analysis based on porosity and permeability multipliers, salinity, and hysteresis effect. Finally, we demonstrated the effectiveness of the seal, and the structural and stratigraphic trapping. Until the development of the current analysis, there is no evidence of public domain studies assessing the storage potential into saline aquifers in Saudi Arabia. This contribution is essential for developing CCUS and promoting a circular carbon economy in line with the Vision of the Kingdom for the future.
36

[en] NUMERICAL MODELING OF CO2 INJECTION IN SALINE AQUIFERS, AIMING TO EVALUATE MINERAL STORAGE / [pt] MODELAGEM NUMÉRICA DA INJEÇÃO DE CO2 EM AQUÍFERO SALINO, OBJETIVANDO AVALIAR O APRISIONAMENTO MINERAL

ROBERTA DOMINGOS RODRIGUES 13 December 2017 (has links)
[pt] Para contribuir com a mitigação das mudanças climáticas, tecnologias com o intuito de promover a redução de emissões dos Gases de Efeito Estufa, como é o caso do dióxido de carbono, tem obtido grande destaque nas pesquisas ultimamente. Uma das alternativas para impedir que todo esse carbono seja liberado para a atmosfera é reinjetar o CO2 nos próprios reservatórios ou em outras formações geológicas próximas. Neste sentido, esta dissertação apresenta uma tecnologia relacionada à captura e armazenamento geológico de CO2 e avalia o processo de injeção de dióxido de carbono em aquíferos salinos. O principal objetivo é avaliar o processo de injeção de dióxido de carbono em aquíferos salinos de rochas carbonáticas, numa escala de tempo de três mil anos, para avaliar o aprisionamento do CO2 em suas diferentes formas, incluindo o armazenamento mineral. Tal estudo também considera na modelagem, as reações químicas entre os componentes na fase aquosa e a difusão molecular do dióxido de carbono na fase aquosa, assim como as reações químicas de dissolução e precipitação mineral. A partir das informações obtidas em literatura, estabeleceu-se as premissas para a simulação do caso base, e gerou-se casos derivados variando individualmente cada uma das seguintes propriedades: difusividade, salinidade, pH e temperatura, no qual avaliou-se a contribuição de cada uma delas nas diferentes formas de armazenamento do CO2. Por fim, concluiu-se que a mineralização do CO2 iniciou-se após aproximadamente 200 anos de simulação. No entanto, devido às lentas taxas da reação de precipitação mineral, a predominância do armazenamento do CO2 ainda foi na forma dissolvida. As propriedades variadas que contribuíram para o aumento do armazenamento mineral de CO2, que é considerada a forma mais estável, foram: menor fator de difusividade, maior salinidade do aquífero, pH básico (pH igual a 8,0) e maior temperatura. / [en] In order to contribute to climatic changes mitigation, technologies aiming the reduction of pollution gases emissions, such as carbon dioxide, have been highlighted in recent researches. One of the alternatives to prevent all this carbon from being released into the atmosphere is to reinject CO2 into reservoirs or in other nearby geological formations. In this sense, this work presents a technology related to the capture and geological storage of CO2 and evaluates the carbon dioxide injection process into saline aquifers. The main objective is to evaluate the carbon dioxide injection process in saline aquifers of carbonate rocks, in a time scale of three thousand years, to evaluate the storage mechanism of CO2 in its different forms, including mineral storage. Such study also considers in the modeling, the chemical reactions between the components in the aqueous phase and the molecular diffusion of the carbon dioxide in the aqueous phase, as well as the chemical reactions of mineral dissolution and precipitation. From the research made and the information gathered in the literature, the premises for the simulation of the base case were established, and derivative cases were generated by individually varying each of the following properties: diffusivity, salinity, pH and temperature, in which the contribution of each property was evaluated on the different CO2 storage forms. Finally, it was concluded that the injected CO2 mineralization process started after approximately 200 years of simulation. However, due to slow rates of the mineral precipitation, the CO2 storage in the dissolved form was still predominant. The different properties that contributed to increase the CO2 mineral storage, which is considered the more estable one, were: lower diffusivity factor, higher aquifer salinity, basic pH (pH equal to 8.0) and higher temperature.
37

Thermochemical-based poroelastic modelling of salt crystallization, and a new multiphase flow experiment : how to assess injectivity evolution in the context of CO2 storage in deep aquifers / Modélisation thermochimique et poroélastique de la cristallisation de sel, et nouveau dispositif expérimental d’écoulement multiphasique : comment prédire l’évolution de l’injectivité pour le stockage du CO2 en aquifère profond ?

Osselin, Florian 20 December 2013 (has links)
Dans un contexte de réduction internationale des émissions de gaz à effet de serre, les techniques de Captage Transport et Stockage de ce{CO2} (CTSC) apparaissent comme une solution à moyen terme particulièrement efficace. En effet, les capacités de stockage géologique pourraient s'élever jusqu'à plusieurs millions de tonnes de ce{CO2} injectées par an, soit une réduction substantielle des émissions atmosphériques de ce gaz. Une des cibles privilégiées pour la mise en place de cette solution sont les aquifères salins profonds. Ces aquifères sont des formations géologiques contenant une saumure dont la salinité est souvent supérieure à celle de la mer la rendant impropre à la consommation. Cependant, cette technique fait face à de nombreux défis technologiques; en particulier la précipitation des sels, dissous dans l'eau présente initialement dans l'aquifère cible, suite à son évaporation par le ce{CO2} injecté. Les conséquences de cette précipitation sont multiples, mais la plus importante est une modification de l'injectivité, c'est-à-dire des capacités d'injection. La connaissance de l'influence de la précipitation sur l'injectivité est particulièrement importante tant au niveau de l'efficacité du stockage et de l'injection qu'au niveau de la sécurité et de la durabilité du stockage. Le but de ces travaux de thèse est de comparer l'importance relative des phénomènes négatif (colmatage) et positif (fracturation) consécutifs à l'injection de ce{CO2} et à la précipitation des sels. Au vu des nombreux résultats de simulations et de modélisation dans la littérature décrivant le colmatage de la porosité, il a été décidé de porter l'accent sur les effets mécaniques de la cristallisation des sels et la possible déformation de la roche mère. Une modélisation macroscopique et microscopique, tenant compte de deux modes possibles d'évaporation induits par la distribution spatiale de l'eau résiduelle a donc été développée afin de prédire le comportement mécanique d'un matériau poreux soumis à un assèchement par injection de ce{CO2}. Les résultats montrent que la pression de cristallisation consécutive à la croissance d'un cristal en milieu confiné peut atteindre des valeurs susceptibles localement de dépasser la résistance mécanique du matériau, soulignant ainsi l'importance de ces phénomènes dans le comportement mécanique global de l'aquifère. Sur le plan expérimental, les travaux ont porté sur l'utilisation d'un nouveau prototype de percolation réactive afin de reproduire le comportement d'une carotte de roche soumise à l'injection et ainsi obtenir l'évolution des perméabilités dans des conditions similaires à celle d'un aquifère / In a context of international reduction of greenhouse gases emissions, CCS (ce{CO2} Capture and Storage) appears as a particularly interesting midterm solution. Indeed, geological storage capacities may raise to several millions of tons of ce{CO2} injected per year, allowing to reduce substantially the atmospheric emissions of this gas. One of the most interesting targets for the development of this solution are the deep saline aquifers. These aquifers are geological formations containing brine whose salinity is often higher than sea water's, making it unsuitable for human consumption. However, this solution has to cope with numerous technical issues, and in particular, the precipitation of salt initially dissolved in the aquifer brine. Consequences of this precipitation are multiple, but the most important is the modification of the injectivity i.e. the injection capacity. Knowledge of the influence of the precipitation on the injectivity is particularly important for both the storage efficiency and the storage security and durability. The aim of this PhD work is to compare the relative importance of negative (clogging) and positive (fracturing) phenomena following ce{CO2} injection and salt precipitation. Because of the numerous simulations and modelling results in the literature describing the clogging of the porosity, it has been decided to focus on the mechanical effects of the salt crystallization and the possible deformation of the host rock. A macroscopic and microscopic modelling has then been developed, taking into account two possible modes of evaporation induced by the spatial distribution of residual water, in order to predict the behavior of a porous material subjected to the drying by carbon dioxide injection. Results show that crystallization pressure created by the growth of a crystal in a confined medium can reach values susceptible to locally exceed the mechanic resistance of the host rock, highlighting the importance of these phenomena in the global mechanical behavior of the aquifer. At the experimental level, the study of a rock core submitted to the injection of supercritical carbon dioxide has been proceeded on a new reactive percolation prototype in order to obtain the evolution of permeabilities in conditions similar to these of a deep saline aquifer
38

Etudes expérimentales et modélisation du comportement de phase et des propriétés de transport des mélanges liés à la capture et au stockage du carbone / Experimental and modelling studies of the phase behaviour and transport properties of mixtures related to carbon capture and storage

Gonzalez Perez, Alfonso 30 November 2016 (has links)
L'objectif principal de ce travail est le développement d'une équation d’état précise pour la détermination des propriétés thermodynamique de mélange de gaz riche en gaz acides (CO2, H2S) contenant des hydrocarbures et autres gaz (impuretés) comme N2, O2, Ar, etc présente lors du stockage du CO2 (CCS). Après comparaisons avec des données expérimentales, nous avons retenu le modèle SAFT-VR Mie qui prédit de manière satisfaisante les masses volumiques pour les composés purs et les équilibres entre phases. Trois types de propriétés de transport ont également été prédites avec le modèle thermodynamique SAFT-VR Mie associé avec deux autres modèles de prédiction des propriétés de transport (TRAPP et DGT). La prédiction de ces propriétés de transport (viscosité et tension superficielle) repose sur une estimation la plus précise possible des masses volumiques. Pour compléter les banques données expérimentales, les équilibres liquide-vapeur concernant le système binaire H2S-Ar ont été déterminés à l'aide d'un dispositif de mesure dont la méthode technique repose sur la méthode "statique analytique" avec échantillonnage des phases (échantillonneur capillaire ROLI). Déplus, à l'aide d'un densimètre à tube vibrant, les masses volumiques de cinq systèmes binaires (H2S - hydrocarbures (méthane, éthane et propane) ont été mesurées. Les masses volumiques d'un système ternaire (CO2/CH4/H2S) et les masses volumiques et les viscosités d'un mélange multi-constituant riche en CO2 ont aussi été mesurées. Les données sont parfaitement représentées par les modèles développés au cours de cette thèse. / The main aim of this research is to develop a thermodynamic model from an accurate equation of state (EoS) for CO2, hydrocarbons and other gases as N2, O2, Ar, etc. The SAFT-VR Mie EoS was selected to study the phase behaviour and transport properties of mixtures related to carbon capture and storage (CCS). In order to asses this new version of SAFT, several equations of state have been compared (PR, SRK and PC-SAFT). SAFT-VR Mie EoS provides very good density predictions for pure component and binary systems according to the comparative study carried out. Therefore, three transport properties were modelled with SAFT-VR Mie and two models based on density predictions from the EoS. Thus, density, viscosity and interfacial tension (IFT) of CO2-rich systems were calculated by this SAFT-EoS (density), TraPP model (viscosity) and DGT (IFT), in the framework of CCS. Some experimental work was done, in order to extend the available literature data. Isothermal vapor-liquid equilibrium of H2S-Ar binary system was determined at three temperatures from 258 to 288 K. Densities of five binary systems of H2S with methane, ethane and propane were measured continuously at 3 temperatures (253, 273 and 293K) and at pressures up to 30MPa. Following the same technique, the density of the ternary system 42%CO2, 40%CH4 and 18%H2S was measured at pressures ranging from 0.2 to 31.5MPa and at 6 temperatures between 253 and 353K. Densities and viscosities of a multicomponent CO2-rich with 50% of impurities were measured at 5 temperatures between 283 and 423 K and at pressures up to 150 MPa.
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Möjligheterna att implementera bio-CCS och CCS på Högdalenverket : En fallstudie över fyra olika koldioxidavskiljningsteknologier och deras kompatibilitet på Högdalenverket med avseende på tekniska, ekonomiska, miljömässiga och energirelaterade aspekter. / The possibilities to implement bio-CCS and CCS at Högdalenverket : A case study about four different carbon capture technologies and their compatibility at Högdalenverket with regards to technical, economical, environmental and energy related aspects

Nilsson, Emma, Östlund, Evelina January 2021 (has links)
Increased carbon dioxide in the atmosphere has raised the attention to Carbon Capture and Storage (CCS). Stockholm Exergi is a company conducting research on CCS and bio-CCS, a form of CCS where biogenic CO2 is captured. This master thesis analyzed the possibilities to implement CCS and bio-CCS at Högdalenverket, one of Stockholm Exergi’s combined heat and power plant with waste incineration. The aim was to investigate advantages and disadvantages with different carbon capture technologies (CC technologies) considering technical, economical, and energy related aspects. Industrial and household waste are incinerated in four boilers at Högdalenverket. Two cases were analyzed, one case with all boilers connected to the CC technology and one case with the boiler with the highest degree of CO2 emission connected. The CC technologies taken into consideration were amine technology, Hot Potassium Carbonates (HPC), Compact Carbon Capture (3C), and Svante. Amine technology and HPC use chemical absorption in static columns. The Amine technology is the most investigated and used one. It uses temperature swing absorption with amines as absorbent. HPC uses pressure swing absorption with potassium carbonate as absorbent. The remaining two are new process intensified technologies. 3C uses rotating packed beds and absorbs CO2 chemically using, most commonly, amines. Svante also uses a rotating technique by chemically adsorbing CO2 with nanomaterial as the solid adsorbent. All CC technologies need steam to regenerate CO2. The steam was assumed to be extracted from the existing steam network at Högdalenverket with a pressure and temperature of 36 bar and 400 degrees. The method used in the study was mainly literature review with peer reviewed articles regarding CCS as base. It was of importance to analyze how the flue gases could affect the CC technologies since the waste has an inhomogeneous composition. The flue gas composition was compiled using external and internal measurements from 2019 and 2020. Furthermore, energy and power calculations were performed to investigate how the heat and electricity delivery would be affected if the different CC technologies were implemented. Moreover, economic calculations regarding the cost for heat and electricity were carried out. Two interviews were also conducted, one with a CCS consultant company and one with internal staff at Högdalenverket. According to the literature review, O2, SO2, and NO2 appeared to be the pollutants causing highest risk of solvent degradation in the flue gases. The high O2 content at Högdalenverket could cause oxidative degradation, especially in amine technology. The SO2 and NO2 content in the flue gases was mainly low and would therefore not significantly affect the technologies. Peeks with high content did however occur and amines, especially within the amine technology, could form toxic and cancerogenic nitrosamines with NO2 which should not be released to the atmosphere. The flue gas composition proved not to be the limiting factor for implementation of CC technology on all incinerators. However, it is costly and complex to handle the variations in flue gas flow which can occur when all boilers are used. The technologies showed high need of heat and electricity which would result in significant reductions in delivery from Högdalenverket. The need of heat and electricity would in turn lead to high operating costs. The Amine technology showed the greatest influence on the heat delivery due to the significant steam requirement to regenerate CO2. HPC showed extreme influence on the delivery of electricity due to the flue gas compression needed in pressure swing processes. Both technologies consist of high columns with significant degree of land use which would be difficult to implement within the limited area at Högdalenverket. As a result of these aspects, HPC and Amine technology are not considered to be suitable technologies to implement at Högdalenverket. However, the master thesis presented measures for energy saving that should be considered before excluding the technologies. One energy saving measure is to find the optimal heat recovery, for example by pinch-analysis. Moreover, composition, concentration, and flowrate of the absorbent can be analyzed. In addition, higher columns are associated with lower need of energy. Finally, modifications of the capture process can be investigated, and one example is to split the flow of the absorbent into two streams into the columns. 3C and Svante are compact technologies that require less land and have potential to fit at more locations at Högdalenverket. The compact design also leads to 50 percent less investments costs compared to the other two technologies. Moreover, these technologies are presented as more resistant against degradation of sorbents, and both requires less energy to regenerate CO2. These technologies are therefore more suitable for implementation at Högdalenverket. A drawback is that they are not yet commercially developed, they are only located at 6-7 at the TRL-scale. TRL stands for Technology Readiness Level and implies how developed the technology is. The scale ranges from one to nine where nine means that the technology is commercially developed. Today, there are no economic incentives for the biogenic part of the CO2 emissions. However, there are investigations ongoing to create a market and economic incentives for the bio-genic part, one of the suggestions is reversed auctions. It is important to investigate methods to reduce the technologies need of heat and electricity, e.g., by finding other ways to extract steam instead of using steam with high exergy. Reducing the need of energy is important in the view of cost reduction, but also to avoid potential transfer of emissions to fossil CO2 generating production. The losses of heat and electricity generation that occur when implementing a CC technology need to be replaced. This replacement could end up being production from fossil fuels if no other options are available. Another aspect that needs to be considered is the suitability of using amines to a greater extent since it could cause serious environmental and health issues.
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Carbon dioxide separation by disc stack centrifuge at low CO2 concentration / Koldioxid separaring via staplad disk centrifug vid låg CO2 halt

Correa Zapisotski, David January 2022 (has links)
Medan världen undergår en klimatkris, nya sätt för att mildra den har undersökts till det korta och långa loppet. Koldioxid är ett ämne som uppmärksammats då stora mängder av den släpps ut till atmosfären på grund av förbränningsprocesser. Då detta sker, ett sätt för att mildra klimatomställningen är genom ”Carbon Capture and Storage”, CCS. Det finns redan metoder för att fånga och separera CO2, genom exempelvis roterande packade säng eller vattnade vägg kolumner. Dock har staplade disk centrifug inte undersökts. Denna rapport har undersökt och använt en staplad disk centrifug för just koldioxid separering, genom användning av vatten och NaOH-lösning som absorbenter. Några parametrar har varierats såsom koncentrationen på NaOH-lösningen, luftflödeshastighet och koldioxid koncentration. Resultaten visade att användning av en staplad disk centrifug separerade inte märkvärdiga mängder av CO2. Det hittades däremot förklaringar till detta och det var att den låga halten CO2, de begränsade mätinstrumenten och det experimentella uppställningen som ej gav tid för absorption att ske. / As the world is going through a climate crisis, ways to mitigate it in the short and long term have been investigated. Carbon dioxide is a molecule of importance due to the amounts that are freely emitted into the atmosphere because of combustion processes. Due to this, one way of many, to mitigate climate change is Carbon capture and storage, CCS. There are also consequently several ways to capture and separate CO2 in post combustion processes, such as the use of rotating packed beds or wetted wall columns, however the use of disc stack centrifuges has not been investigated for this application. This paper has investigated and used a disc stack centrifuge for this purpose, by using water and NaOH solution as aerosol absorbents. Some parameters have been varied such as NaOH concentration, air flow speed and carbon dioxide concentration.  Results had shown that the use of a disc stack centrifuge did not yield considerable CO2 separation, however, an explanation for this was found to be due to low CO2 concentration and limited measuring instruments as well as a setup that did not make it possible for absorbent and CO2 to fully react and be efficiently separated.

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