Дисертації з теми "Renewable gase"
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Thomson, Rachel Camilla. "Carbon and energy payback of variable renewable generation." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/8875.
Повний текст джерелаАнотація:
The continued drive to reduce Greenhouse Gas (GHG) emissions in order to mitigate climate change has led to an increase in demand for low-carbon energy sources, and the development of new technologies to harness the available energy in the wind, waves and tides. Many controversies surround these technologies, however, particularly with regards to their economic cost, environmental impacts and the implications of the variability of their output for security of the electricity supply. In order to make informed policy decisions on future developments of the electricity system, it is necessary to address these controversies and confirm the environmental, economic and social sustainability of these new renewable generators. This thesis specifically examines two key issues: whether new variable-output renewable energy generators actually deliver a net reduction in greenhouse gas emissions over their lifetimes, and whether they produce a viable energy return on energy investment. Although renewable energy sources are themselves ‘carbon free’, GHG emissions (and energy consumption) occur during the construction, maintenance and decommissioning of the generator infrastructure required to convert this energy into electricity. Furthermore, the variability of the output power from such generators has implications for the operation of the grid - there may be a requirement for additional reserve capacity and the increased part-loading of conventional plant is likely to reduce its operating efficiency. Carbon and energy paybacks are measures of the time required for a new renewable installation to offset these life cycle impacts. The work presented in this thesis examines both the life cycle impacts and the GHG emissions displacement of variable renewable generation, using Great Britain as a case study, in order to provide a basis for significantly more robust and reliable estimates of carbon and energy paybacks. The extensive literature survey concentrates on two key areas: current calculation methodologies and estimates for life cycle carbon and energy consumption of power generators; and the marginal emissions displacement of variable renewable generation. A detailed life cycle assessment of the Pelamis wave energy converter is presented, which sets the embodied carbon and energy in the context of the wider environmental impacts and includes an examination of the effect of different assumptions on the analysis results. In order to investigate the true emissions displacement of renewable generation, a historical analysis of real data from the National Grid was carried out, identifying the marginal displacement factor of wind power and taking into account the effect of the efficiency penalties of conventional plant. The findings of the analyses presented in this thesis are combined with information from the literature to examine the actual carbon and energy payback of existing renewable generation infrastructure on the British grid, and to provide detailed recommendations for future carbon and energy payback calculations.
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Ghalebani, Alireza. "Renewable Energy Investment Planning and Policy Design." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6243.
Повний текст джерелаАнотація:
In this dissertation, we leverage predictive and prescriptive analytics to develop decision support systems to promote the use of renewable energy in society. Since electricity from renewable energy sources is still relatively expensive, there are variety of financial incentive programs available in different regions. Our research focuses on financial incentive programs and tackles two main problem: 1) how to optimally design and control hybrid renewable energy systems for residential and commercial buildings given the capacity based and performance based incentives, and 2) how to develop a model-based system for policy makers for designing optimal financial incentive programs to promote investment in net zero energy (NZE) buildings.
In order to customize optimal investment and operational plans for buildings, we developed a mixed integer program (MIP). The optimization model considers the load profile and specifications of the buildings, local weather data, technology specifications and pricing, electricity tariff, and most importantly, the available financial incentives to assess the financial viability of investment in renewable energy. It is shown how the MIP model can be used in developing customized incentive policy designs and controls for renewable energy system.
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Khan, MD Ershad Ullah. "Renewables Based Polygeneration for Rural Development in Bangladesh." Doctoral thesis, KTH, Kraft- och värmeteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-205556.
Повний текст джерелаАнотація:
Despite the country's rural electrification programme, kerosene is the predominant source for lighting, and unsustainable and polluting woody biomass is virtually the only option available for cooking. The rural population also struggles with unsafe drinking water in terms of widespread arsenic contamination of well water. The present work has taken an integrated approach in an attempt to mitigate problems through small-scale polygeneration, a concept linking renewable energy sources to these energy needs via novel energy conversion systems. Anaerobic digesters (AD) for biogas production are promising in the rural setting, and field surveys have identified problems in the construction, maintenance and operation of existing AD, particularly in overall performance of household digesters. Based on these results, a number of operational and technological improvements are suggested for employing digesters in polygeneration units. This study also examines one approach for small-scale, low cost arsenic removal in groundwater through air gap membrane distillation, a thermally-driven water purification technology. Integration of biogas production with power generation and water purification is an innovative concept that lies at the core of feasibility analyses conducted in this work. One of the case studies presents a new concept for integrated biogas based polygeneration and analyzes the techno-economic performance of the scheme for meeting the demand of electricity, cooking energy and safe drinking water of 30 households in a rural village of Bangladesh. The specific technologies chosen for the key energy conversion steps are as follows: plug-flow digester; internal combustion engine; and membrane distillation. One major concern is local feedstock availability for the digester, since a single feedstock is impractical to serve both cooking, lighting and water purification systems. In this circumstance solar PV could be a potential option for integrated hybrid systems.Bangladesh har varit föremål för en svår energikris (bristande el- och gasnät) de senaste tre decennierna. Landsbygden, som innefattar 75 % av befolkningen, har varit särskilt drabbad. Trots landets elektrifieringsprogram av landsbygden är fotogenlampor den företrädande ljuskällan, medan förorenande och ohållbar träbaserad biomassa är praktiskt taget det enda alternativet för matlagning. Landsbygden kämpar samtidigt mot osäkert dricksvatten, på grund av utbredd arsenikförgiftning av brunnsvatten, med negativa hälsoeffekter som följd. Tillgång till ren energi och säkert dricksvatten är verkliga behov bland de fattiga på landsbygden, för ökad välfärd. Detta arbete antar ett integrerat tillvägagångssätt för att försöka lösa dessa problem genom småskalig polygenerering. Detta koncept länkar samman förnyelsebara energikällor av biomassa och sol med energibehoven, genom nya energiomvandlingssystem. Anaerobiska rötkammare för biogasproduktion är lovande för landsbygdsmiljö, även om det för närvarande råder en betydande klyfta mellan den tekniska och kostandseffektiva potentialen och faktisk implementering på grund av bristande tekniskt kunnande och tillgång på råmaterial, höga installations- och driftkostnader, och begränsade användartillämpningar. Intervjuundersökningar visar på problem i konstruktion, underhåll och drift av befintliga anaerobiska rötkammare. Särskilt den generella prestandan hos hushållsrötkammare identifieras som bristfällig. Utifrån dessa resultat föreslås en rad drift- och teknikförbättringar för att utnyttja rötkammare i polygenereringssystem. Denna studie undersöker även en metod för småskalig och kostnadseffektiv arsenikrening av grundvatten genom membrandestillation med luftspalt (Air Gap Membrane Distillation, AGMD), vilket är en termiskt driven vattenreningsteknik. Resultat från en experimentell undersökning visar att den undersökta AGMD-prototypen är kapabel att uppnå utmärkt separationseffektivitet med hänsyn till arsenikrening. Parametriska studier med fokus på varierande kylvattentemperatur illustrerar möjligheten att integrera AGMD-teknik i diverse termiska system. Integrering av biogasproduktion med kraftproduktion och vattenrening är ett innovativt koncept som utgör kärnan av förstudierna utförda i detta arbete. En av studierna visar ett nytt koncept för biogasbaserad polygenerering och analyserar den techno-ekonomiska prestandan av metoden för att möta efterfrågan av elektricitet, matlagningsvärme och säkert dricksvatten för 30 hushåll i en Bangladeshisk by på landsbygden. De specifika tekniker som valts för energiomvandlingsstegen är följande: plugg-flödesrötkammare, förbränningsmotor och en AGMD-enhet. Termodynamisk utvärdering inklusive mass- och energibalans av systemet undersöktes tillsammans med produktionskostnaden för elektricitet, matlagningsgas, och säkert dricksvatten. Även återbetalningsperiod och internräntan undersöktes. För att bemöta energi- och arsenikproblemen i Bangladesh, indikerar resultaten att detta polygenereringssystem är mycket mer konkurrenskraftigt och lovande (med avseende på produktionskostnaderna) jämfört med andra tillgängliga tekniker. Ett viktigt problem för rötkammaren är tillgången till lokalt råmaterial, eftersom en ensam källa till råmaterial är opraktiskt för att tillgodose efterfrågan från både matlagning, belysning och vattenrening. I detta fall kan solceller vara ett potentiellt alternativ för integrerade hybridsystem. Teknisk värdering och optimering har genomförts för elektricitet med verktyget HOMER (Hybrid Optimization of Multiple Energy Resources), för ett polygenereringssystem beläget i byn Panipara i Faridpur. Resultaten visar att systement kan tillgodoses det dagliga elektricitetsbehovet och samtidigt producera 0.4 m3 matlagningsbränsle och 2-3 L/person rent dricksvatten. Kostnadsuppskattningar visar att denna metod är högst gynnsam jämfört med andra förnyelsebara alternativ (t ex vind-, vatten-, biobränslebaserad- eller geotermisk energi).
QC 20170419
SIDA – the Swedish International Development Cooperation Agency, Department for Research Cooperation, SAREC- project no. SWE-2011-135
STEM-Fjärrsyn project 2014
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Hughes, Dimitri. "Facilitated characterization of a catalytic partial oxidation fuel reformer using in situ measurements." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31646.
Повний текст джерелаАнотація:
Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2010.Committee Co-Chair: Haynes, Comas; Committee Co-Chair: Wepfer, William; Committee Member: Jeter, Sheldon. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Mkosi, Lungisa. "Characterization of various garden grass species for energy conversion in a down draft biomass gasifier." Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/5817.
Повний текст джерелаАнотація:
Energy plays a vital role in socio-economic development and raising living standards of human beings. The overreliance on fossil fuels results in the depletion of fossil fuels as well as environmental pollution from the green-house gases that result from the use of fossil fuels. Biomass feedstock are able to ameliorate this situation by utilizing the CO2 that has been used by plants during photosynthesis. This study investigated the suitability of the three garden grass species (Chloris gayana, Cynodon dactylon and Pennisetum clandestum) as biomass feedstock for gasification purposes. The three garden grass species were collected at the Alice Campus of the University of Fort Hare. These grass species were characterized using elemental analyser (CHNS), FT-IR, EDX and TGA. The Activation energy (Ea) of the three grass species were 48.22 kJ/mol for P. clandestum, 36.8 kJ/mol for C. gayana and 258 kJ/mol for C. dactylon. Of the three grass species, C. gayana had the lowest Activation energy of 36.8 kJ/mol and also had the highest maximum efficiency of 69 percent compared to 65.3 percent for P. clandestum and 63.5 percent for C. dactylon. Actual gasification was not carried out but the results on maximum efficiency were obtained from computer simulation of gasification.
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González, García-Cervigón Maria Inmaculada. "Adsorption and oxidation of NO to NO2 over a renewable activated carbon from coconut." Thesis, Brunel University, 2016. http://bura.brunel.ac.uk/handle/2438/13678.
Повний текст джерелаАнотація:
The NOx health and environmental problems make necessary to reduce this gaseous emission from different sources. Furthermore, its increase in the last years and the difficulties to remove it with after-treatment systems already in the market make more urgent the development of new techniques. The purpose of this investigation is to study the low temperature catalytic oxidation of NO to NO2 and its adsorption over a renewable activated carbon (AC) from coconut shell. The present research presents the results of experimental work carried out using a laboratory scale reactor to investigate the low temperature catalytic oxidation of NO. Activated carbon was housed in the reactor and tests were carried out with different reactor sizes, different activated carbon forms and shapes, different gas mixtures at different temperatures and different levels of humidity to simulate dry and wet particulate-free diesel engine exhaust gas. The effects of addition of ozone in the gas on the NO oxidation were also explored. Gas analysis upstream and downstream of the catalytic reactor was carried out in all cases during the charge and regeneration of the AC. An extensive literature review in conjunction with measurement of some properties of the activated carbon helped to understand better its characteristics and behaviour. The results of this study indicate that in the case of dry gas, the activated carbon initially acts as an adsorber and only after operation of several hours, the NO oxidation that takes place in the reactor results in increased NO2 levels in the product gas. The NO conversion is affected by the activated carbon form and reaction conditions including temperature, humidity, oxygen, NO, CO2 content in the inlet gas, temperature, space velocity, linear gas velocity, residence time, reactor shape, AC pretreatment and lifespan. Water vapour has a detrimental effect on the conversion of NO to NO2 before the AC reaches the steady-state conditions. On the other hand, ozone is effective in converting NO to NO2 at room temperature. This research has developed some findings not studied or reported by other researches before and confirms and/or complements results reported in the literature review by other groups, which will benefit the development of a renewable after-treatment system of NOx emissions.
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Butler, Kirt Gordon. "Relationship of Solar Energy Installation Permits to Renewable Portfolio Standards and Insolation." Thesis, Walden University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3739574.
Повний текст джерелаАнотація:
Legislated renewable portfolio standards (RPSs) may not be the key to ensure forecast energy demands are met. States without a legislated RPS and with efficient permitting procedures were found to have approved and issued 28.57% more permits on average than those with a legislated RPS. Assessment models to make informed decisions about the need and effect of legislated RPSs do not exist. Decision makers and policy creators need to use empirical data and a viable model to resolve the debate over a nationally legislated RPS. The purpose of this cross-sectional study was to determine if relationships between the independent variables of RPS and insolation levels and the dependent variable of the percentage of permits approved would prove to be a viable model. The research population was 68 cities in the United States, of which 55 were used in this study. The return on investment economic decision model provided the theoretical framework for this study and the model generated. The output of multiple regression analysis indicated a weak to medium positive relationship among the variables. None of these relationships were statistically significant at the 0.05 level. A model using site specific data might yield significant results and be useful for determining which solar energy projects to pursue and where to implement them without Federal or State mandated RPSs. A viable model would bring about efficiency gains in the permitting process and effectiveness gains in promoting installations of solar energy-based systems. Research leading to the development of a viable model would benefit society by encouraging the development of sustainable energy sources and helping to meet forecast energy demands.
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Weber-Newth, Francesca. "The game of urban regeneration : culture & community in London 2012 and Berlin's Mediaspree." Thesis, University of Aberdeen, 2015. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=227623.
Повний текст джерелаАнотація:
This thesis explores who 'wins' and 'loses' in urban regeneration, and the mechanisms behind this process. I take a comparative approach, focusing on two neighbourhoods – Hackney Wick Fish Island and Rudolfkiez – that are adjacent to the large-scale regeneration schemes London 2012 and Mediaspree in Berlin. By analysing how urban regeneration is experienced on the ground, my aim is to disrupt the notion that Olympic-led regeneration is any different from other forms of neoliberal urban development. I adopt Pierre Bourdieu's view of the social world as made up of competitive 'games' to demonstrate that urban regeneration is a game with winners and losers in which language constructions play a decisive role. I use the lenses of 'culture' and 'community' to analyse the dynamics of urban regeneration by documenting how the two concepts are strategically employed, and who has a monopoly over 'legitimate' definitions. I draw on a mixed methodology, including interviews, visual methods, document analysis and participant observation. Analysis of the empirical data demonstrates that despite significantly different historical contexts, political ideologies and fiscal climates, the power dynamics of urban development converge in Berlin and London. My analysis shows that, while there is a tendency for 'the winners to keep winning and the losers to keep losing', protest networks and critical artistic practices can change the language of the game and therefore have the potential to shift the dominant neoliberal logic. My aim is to reveal these subtleties and nuances of the game.
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Rameesdeen, Sabra Banu. "Investigation of the ketonization reaction of renewable acids and esters." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amslaurea.unibo.it/25424/.
Повний текст джерелаАнотація:
Ketonization is a promising reaction for the upgrading of bio oils produced from biomass and it is used for the preparation of highly valuable asymmetrical ketones such as di-hydrocalchone (HC) and acetyl furan (Ac-Fur). But, they are produced in the liquid-phase with poorly sustainable processes, e.g. Friedel-Crafts acylations (Ac-Fur) and tandem acylation/alkylation (HC) with homogeneous Lewis acid catalysts or oxidations with organic peroxides and excess MnO2 (HC) or H2O2 and inorganic homogeneous catalysts. The development of an alternative gas-phase process to produce HC and Et-Fur by means of cross-ketonization is highly desirable because it would avoid the issues of traditional methods. Moreover, most reactants required for the ketonization process could be prepared from renewable resources. This thesis was dedicated to the study of the cross-ketonization between ethyl benzoate (EB) and ethyl-3-phenylpropionate (EPP) and between ethyl acetate (EtOAc) and ethyl-2-furoate (Et-Fur) to synthetize HC and 2-Ac-Fur respectively. Ketonization of EPP with EB was carried out over different metal oxides (namely ZrO2, La2O3, CeO2) and it was found that ZrO2 was the best catalyst, probably due to its amphoteric properties. Over this material, the formation of HC was maximized by a large excess of EB (EB/EPP= 9) and by a high reaction temperature (350 °C); the effect of water co-feeding was also evaluated in the attempt of maximize HC yield by hydrolyzing EB in situ and producing the more reactive BA, but it was found that instead water reduces catalyst activity. Similar conclusions were drawn investigating the ketonization of Et-Fur with EtOAc over ZrO2. In conclusion, HC was obtained with 80% selectivity at 77% EPP conversion at 350 °C, with 1 second and with a EB/EPP molar ratio = 9, while Ac-Fur was obtained with 82% selectivity at 82% Et-Fur conversion in the same conditions but with a lower EtOAc/Et-Fur molar ratio of 4.
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Dabrowska, Kornelia Anna. "LINKING PROFITABILITY, RENEWABLE ENERGY, AND EXTERNALITIES: A SPATIAL ECONOMETRIC ASSESSMENT OF THE SOCIO-ECONOMIC IMPACT OF OHIO DAIRIES." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1269360484.
Повний текст джерела
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Archer, Nneka Cori-anne. "Strategies Utility Managers Used to Implement Renewable Energy Technologies in the Caribbean." ScholarWorks, 2015. https://scholarworks.waldenu.edu/dissertations/1771.
Повний текст джерелаАнотація:
Government officials in the Caribbean are encouraging the production of electricity from renewable energy sources to reduce the impact of high electricity rates to customers due to region's dependency on imported fossil fuel. The purpose of this single-case study was to explore the strategies electric utility managers in the Caribbean used to implement renewable energy technologies. The diffusion of innovation theory served as the conceptual framework for the study. Three managers of an electric utility in the Caribbean, who had created strategies to implement renewable energy technologies, participated in face-to-face semistructured interviews. These managers provided in-depth information on approaches used to implement these technologies. Three themes emerged from the thematic analysis of data that were collected from the semistructured interviews and document reviews: development and integration of renewable energy technologies into utility operations, avoidance of future investments in fossil fuels, and inclusion of key stakeholders in the transition to implementing renewable energy technologies. The implications for social change to the Caribbean region from a successful implementation of the technologies may include employment opportunities through the creation of new industries, eradication of energy poverty, and a healthier and cleaner environment. Also, government officials can save significant foreign exchange by not having to import fossil fuel for electricity generation and use these savings to invest in other sectors that can provide further economic and social growth for the people of the region.
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Zeller-Powell, Christine Elizabeth. "Defining Biomass as a Source of Renewable Energy: The Life-Cycle Carbon Emissions of Biomass Energy and a Survey and Analysis of Biomass Definitions in States' Renewable Portfolio Standards, Federal Law, and Proposed Legislation." Thesis, University of Oregon, 2011. http://hdl.handle.net/1794/11483.
Повний текст джерелаАнотація:
xii, 97 p.Electricity generated from woody biomass material is generally considered renewable energy and has been considered carbon neutral. However, recent criticism from scientists argues that the greenhouse gas (GHG) emission profile of bioenergy is nuanced and the carbon neutral label is inappropriate. An initial carbon debt is created when a forest is harvested and combusted for bioenergy. Because forests re-grow over a period of years, life cycle analyses show that bioenergy generated from whole trees from forests may not reduce GHG emissions in the short term, as required to combat climate change. State renewable portfolio standards and federal laws and proposed legislation designed to incentivize renewable energy typically define eligible forms of biomass that qualify for these incentives. Most of these definitions are very broad and do not account for GHG emissions from bioenergy. Federal and state laws should incorporate life cycle analyses into definitions of eligible biomass so that these laws incentivize biomass electricity that reduces GHG emissions in the next several decades.
Committee in charge: Roberta Mann, Chairperson; Scott Bridgham, Member
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Kiedanski, Diego. "Mechanisms and architectures to encourage the massive and efficient use of local renewable energy." Electronic Thesis or Diss., Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAT036.
Повний текст джерелаАнотація:
Le déploiement massif de ressources d'énergie renouvelable distribuée (RED) représente une opportunité majeur pour atteindre les objectifs de réduction des émissions de carbone en Europe, mais aussi dans le monde entier. Visant à mobiliser des capitaux publics et privés, plusieurs plans ont été développés pour placer les clients finaux au cœur de la transition énergétique, dans l'espoir d'accélérer l'adoption de l'énergie verte en augmentant son attractivité et sa rentabilité. Certains systèmes proposés incluent la création de marchés locaux d'énergie, où les résidences peuvent vendre leur énergie dans leur quartier à un prix plus élevé que celui que les fournisseurs classiques seraient prêts à payer (mais inférieur à ce que les autres clients paieraient à ces fournisseurs); des investissement partagés, les consommateurs possédant dans ce cadre un générateur décarboné et/ou du stockage pour lesquels ils obtiennent des dividendes dans un contexte d’autoconsommation collective où plusieurs familles sont `` cachées '' derrière le même compteur intelligent, leur permettant d'optimiser leur profil de consommation agrégé et donc maximiser la valeur de leur investissement. L'un des principaux objectifs de la thèse est de fournir des méthodes pour augmenter les gains potentiels et des modèles pour évaluer l’impact que l’on peut attendre de ces différentes solutions, afin qu’elles deviennent une incitation plus forte à la génération et usage d’énergies renouvelables, car celles-ci joueront un rôle crucial dans la lutte contre le changement climatique seulement si elles sont correctement mises en œuvre. Pour ce faire, nous concevons un cadre permettant de concevoir et de comparer divers paradigmes «d’investissements partagés et d’échanges monétisés locaux de l’énergie», dont le potentiel de «gains» se traduit par une incitation forte à leur mise en œuvre. Dans le cadre d’échanges monétisés locaux d'énergie, nous étudions les interactions entre prosommateurs (consommateurs avec capacité de production et éventuellement de stockage) situés dans le même réseau Basse Tension, éventuellement derrière le même départ. Dans nos systèmes, ces prosommateurs seront toujours connectés au réseau électrique principal et ils auront la possibilité, comme ils le font aujourd'hui, d'acheter et de vendre à un opérateur de services de distribution d’électricité, suivant une politique tarifaire connue à l’avance (un taux forfaitaire ou un temps d'utilisation, pour exemple). Pour que ces agents bénéficient pleinement des avantages des échanges locaux d'énergie, nous supposons qu'ils possèdent des appareils (tels que des batteries) qui, sans modifier leur demande énergétique interne (sans changer leur comportement d’usage), peuvent leur permettre de modifier leur demande énergétique nette vue de l'extérieur de leur domicile. En modélisant les prosommateurs comme des maximisateurs rationnels de l'utilité (que nous définissons), ils planifieront les flux entrant et sortant de leur batterie pour diminuer le coût associé à leur demande nette d'énergie (avec comme signalé, une demande perçue qui reste inchangée). Dans la première partie de la thèse, nous étudions des modèles concurrentiels dans lesquels les prosommateurs vendent leur surplus à leurs voisins via un marché local d'énergie. Nous analysons différents types de marchés et donc différentes stratégies que les acteurs pourraient utiliser pour participer à ces marchés, ainsi que leur impact sur le réseau électrique et sur le gestionnaire du réseau de distribution. Dans la deuxième partie de la thèse, nous explorons les incitations qui peuvent être mises en œuvre par la coopération. À cet égard, nous utilisons la théorie des jeux coopératifs pour modéliser l'investissement partagé dans l’acquisition de dispositifs de stockage énergie et de panneaux photovoltaïques (PV) par un groupe de prosommateursTo meet carbon reduction goals in Europe but worldwide too, a large number of renewable distributed energy resources (DER) still need to be deployed.Aiming at mobilizing private capitals, several plans have been developed to put end-customers at the heart of the energy transition, hoping to accelerate the adoption of green energy by increasing its attractiveness and profitability.Some of the proposed models include the creation of local energy markets where households can sell their energy to their neighbors at a higher price than what the government would be willing to pay (but lower than what other customers normally pay), shared investment models in which consumers own a carbon-free power plant such as a wind turbine or a solar farm and they obtain dividends from its production to collective auto-consumption models in which several families are ‘hidden’ behind the same smart meter, allowing them to optimize their aggregated consumption profile and therefore maximizing the value of their DER.One of the main objectives of the thesis is to understand these different incentives as they will play a crucial role in tackling climate change if correctly implemented. To do so, we design a framework ‘local energy trading’ that encompasses a large number of incentives.In the context of local energy trading, we study the interactions of prosumers (consumers with generation capabilities) located in the same Low Voltage network, possibly behind the same feeder. These prosumers will still be connected to the main power grid and they will have the option, as they do today, to buy and sell to/from their utility company at a fixed price (a flat rate or a Time-of-Use, for example). For these agents to fully benefit from the advantages of local energy trading, we shall assume that they own appliances (such as batteries) that, without changing their perceived energy demand, can enable them to change their net energy demand as seen from outside their homes. Modeling prosumers as rational utility maximizers, they will schedule their battery to decrease the cost associated with their net energy demand (as their perceived demand remains unchanged).In the first part of the thesis, we investigate competitive models in which prosumers sell their surplus to their neighbors via a local energy market. We analyze different strategies that players could use to participate in these markets and their impact on the normal operation of the power grid and the Distribution System Operator. In this regard, it is shown that sequential markets can pose a problem to the system and a new market mechanism that exploits domain knowledge is proposed to increase the efficiency of the local trades.In the second part of the thesis, we delve into incentives that can be implemented through cooperation. In this regard, we use cooperative game theory to model the shared investment into energy storage and photovoltaic panels (PV) by a group of prosumers. For the studied model we show that a stable solution (in the core of the game) exists in which all participants cooperate and we provide an efficient algorithm to find it. Furthermore, we also show that cooperation is stable for participants that already own batteries and PVs but prefer to operate them in coordination to increase their value, effectively implementing collective auto-consumption.Finally, we demonstrate how to integrate both models: the shared investment and the cooperative control of existing resources into a single cooperative framework which also enjoys the existence of stable outcomes. For this later model, we propose to decouple the return over investments (ROI) obtained between the ROI produced by the investment in hardware and the ROI obtained by cooperation itself. By doing so, we can offer the former profit to external investors to raise the required capital (although nothing forbids the member of the coalition to contribute) and the latter to the actual consumers
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Chau, Long-yee Feon, and 周朗怡. "Changing the rules of the game: an examination of citizen participation in Hong Kong's urban renewal." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45817947.
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McGill, Kristin Li. "Potential Solar Consumers' Understanding of Energy Policy Development in Hawaiâi." ScholarWorks, 2019. https://scholarworks.waldenu.edu/dissertations/7489.
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Hawaiâi has implemented renewable energy goals that assume continued investments by solar consumers who seem unaware of their role in the policy's success. Without the renewable resource generation that will come from these investments, the state will be unable to achieve its energy mandate. Using Sabatier and Jenkins-Smith's advocacy coalition framework and Ajzen's theory of planned behavior as the foundation, the purpose of this study was to better understand the perspectives of potential solar consumers on the Island of Oâahu regarding the state's renewable portfolio standards, their level of knowledge regarding consumer impact on this policy, and their perceptions of the roles of the public utilities commission and electric utility company in the implementation of projects associated with achieving the state's energy goals. Data were collected through interviews with 17 participants who represented a small portion of consumers who had begun the solar program application process but had not received approval to install panels at their residences. These data were inductively coded and subjected to a thematic analysis. Key findings indicate that consumers lack sufficient education about the state's energy goals, and that their participation in the policy process is essential for the continued growth of customer-sited solar installations. Implications for positive social change stemming from this study include recommendations for policymakers and solar program developers to engage in more inclusive educational outreach with consumers regarding the state's required renewable energy goals.
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Savage, William. "The Full Cost of Renewables: Managing Wind Integration Costs in California." Scholarship @ Claremont, 2012. http://scholarship.claremont.edu/pomona_theses/57.
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Wind power will be an important component of California's aggressive strategies to meet its greenhouse gas reduction targets by the year 2020. However, the costs of integrating wind power's variable and uncertain output are often ignored. I argue that California must take prudent action to understand, minimize, and allocate wind integration costs. A review of numerous studies suggests that for wind penetration levels below 20%, integration costs should remain modest. However, costs are heavily dependent on market structure, and I suggest numerous ways that California can optimize its market design to manage wind integration costs.
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Bortot, Baptiste. "Gas for Balancing of Variable Power Generation : A Systemic Case Study." Thesis, KTH, Elektriska energisystem, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-144860.
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With the increasing share of variable renewable generation, balancing electric powersystems could become a major concern for system operators because of their variableand hardly predictable nature. However, gas technologies appear as a solutionto provide this flexibility, but the impacts on the gas power system have hardly beeninvestigated. In this thesis, consulting reports on the subject matter, regulator suggestions andgas-electricity interaction models in scientific literature are studied and four sourcesare identified to be used for balancing: linepack, storage facilities, liquefied natural gasand intraday gas supply from adjacent areas. Then, a gas-electricity model for flexibility supply is designed and three case studies are simulated in order to analyze bothgas and electric power systems’ behaviors. In these case studies, electricity generation,contribution of gas sources and costs are analysed. The study concludes that critical situations on gas market that can occur, e.g. incases of large variation in the net electricity demand and limited availability of linepackand storage facilities, the need of intraday modulation can exceed the possibilities toprovide for it. Then, gas cannot be supplied to power plants during peak periods, andmore gas than necessary is used during off-peak periods. The case studies also showthat day-ahead forecast errors in variable renewable generation can be handled mucheasier than variations by the gas system but leads to higher costs.
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Taliotis, Constantinos. "Large scale renewable energy deployment - Insights offered by long-term energy models from selected case studies." Doctoral thesis, KTH, Energisystemanalys, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-207364.
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The United Nations’ Sustainable Development Goal 7 (SDG7) of Agenda 2030 calls for an increase in the use of renewable energy sources, among other targets. The percentage of fossil fuel-fired thermal generation for electricity is increasingly being reduced as renewable energy technologies (RET) advance in cost-competitiveness, and as greenhouse gas and industrial air pollutant emission limits become more stringent. In certain cases, renewable energy contributes to energy security by improving a nation’s trade balance, since local resources are harnessed and imports are reduced. RET investments are becoming more frequent gaining a sizeable share in the electric power mix of numerous countries. However, RET is affected by existing fossil fuel-fired electricity generation, especially in countries that have domestic reserves. While coal may be dirty, others such as natural gas provide multiple benefits, presenting a challenge to renewables. Additionally, RET endowment varies for each geographical location. This often does not correspond to the location of major electricity demand centers. Therefore, large scale RET adoption and integration becomes logistically more cumbersome, as it necessitates existence of a developed grid network. Utilizing a series of analyses in two different settings – Africa and Cyprus – this thesis draws insights on RET growth policy and the level of technology representation in long term energy models. In order to capture specific challenges of RET integration, enhancements in traditional long-term energy system models are called for and carried out. The case of Africa is used to assess adoption of RET under various trade scenarios. It is home to some of the world’s greatest RET resource potential and the single largest potential RET project, Grand Inga. While, the island of Cyprus has goals of introducing large percentages of RET into its electric power mix. Each have important idiosyncrasies which are reflected in the analysis. On the one hand, natural gas competes with RET in Cyprus and forms a key transition fuel away from oil. On the other hand, lack of cross-border interconnectors limit RET project development across Africa.QC 20170519
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Thayer, Roland P. "A Policymaker's Guide to Feed-In Tariffs: Encouraging a Responsible Transition to Renewable Electricity in California." Scholarship @ Claremont, 2013. http://scholarship.claremont.edu/pomona_theses/87.
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The feed-in tariff is a flexible, yet effective mechanism in promoting the proliferation of renewable electricity in California. The tariff creates a stable investment environment that protects both the utilities and the renewable electricity generators. Not only does the system foster capacity growth, but also technological advancement to the point where renewable electricity can compete in the market without assistance. From an environmental standpoint, the feed-in tariff contributes significantly towards achieving the emissions reduction goals set forth by AB32 without causing harmful increases to electricity prices.
The feed-in tariff model has been used in countries all over the world and in countless variations. The California model is certainly unique, using a dynamic combination of eligibility requirements, pricing mechanisms, and degression rates. Flaws can already be spotted in the system, but it is too early to tell what type of market effects will truly prevail. The key will be to analyze the market effects as they happen and adjust the tariff accordingly. In the meantime, it would be advantageous to pursue more aggressive green marketing campaigns in order to establish meaningful social norms in favor of environmentally responsible goods and practices. These strong social norms will help to ensure quicker and more effective transitions to green products in the future, including the complete transition to renewable electricity over the coming generations.
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He, Youbiao. "The Energy Management of Next-generation Microgrid Systems." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1500907510831555.
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Hobson, Alan George Cawood. "Optimising the renewal of natural gas reticulation pipes using GIS." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52980.
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Thesis (MA)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: A major concern for Energex, Australia's largest energy utility in South East Queensland, is the escape of natural gas out of their reticulation systems. Within many of the older areas in Brisbane, these networks operate primarily at low and medium pressure with a significant percentage of mains being cast iron or steel. Over many years pipes in these networks have been replaced, yet reports show that unaccounted for gas from the same networks remain high. Furthermore, operation and maintenance budgets for these networks are high with many of these pipes close to the end of their economic life. When operation and maintenance costs exceed the costs of replacement, the Energex gas utility initiates projects to renew reticulation networks with polyethylene pipes. Making decisions about pipe renewal requires an evaluation of historical records from a number of sources, namely: • gas consumption figures, • history of leaks, • maintenance and other related cost, and • the loss of revenue contributed by unaccounted for gas. Financial justification of capital expenditure has always been a requirement for renewal projects at the Energex gas utility, however the impact of a deregulation in the energy utility market has necessitated a review of their financial assessment for capital projects. The Energex gas utility has developed an application that evaluates the financial viability of renewal projects. This research will demonstrate the role of GIS integration with the Energex financial application. The results of this study showed that a GIS integrated renewal planning approach incorporates significant benefits including: • Efficient selection of a sub-network based on pipe connectivity, • Discovery of hidden relationships between spatially enabled alphanumeric data and environmental information that improves decision making, and • Enhanced testing of proposed renewal design options by scrutinizing the attributes of spatial data.
AFRIKAANSE OPSOMMING: 'n Groot bron van kommer vir Energex, Australië se grootste energieverskaffer in Suidoos- Queensland, is die verlies van natuurlike gas uit hul gasdistribusie netwerke. In 'n groot deel van ouer Brisbane opereer hierdie netwerke hoofsaaklik teen lae en medium druk, met 'n aansienlike persentasie van hoofpyplyne wat uit gietyster of staal bestaan. Al is sommige pyplyne in hierdie netwerke met verloop van tyd vervang, maak verslae dit duidelik dat 'n groot deel van die gas in hierdie netwerke steeds langs die pad verlore gaan. Die operasionele - en onderhoudsbegrotings vir hierdie netwerke is boonop hoog, met 'n groot persentasie van die pyplyne wat binnekort aan die einde van hulle ekonomiese leeftyd kom. Wanneer operasionele- en onderhoudsonkostes die koste van vervanging oorskry, beplan Energex se gasvoorsienings-afdeling projekte om verspreidingsnetwerke te hernu met poli-etileen pype. Om sinvolle besluite te neem tydens pyplynhernuwings, word verskeie historiese verslae geraadpleeg, insluitend: gasverbruikvlakke, lekplek geskiedenis rekords, onderhoud- en ander verwante onkostes, asook die verlies van inkomste weens verlore gas. Alhoewel finansiële stawing van kapitale uitgawes nog altyd 'n voorvereiste was tydens hernuwingsprojekte by Energex, het die impak van privatisering op die energieverskaffingsmark dit noodsaaklik gemaak om hulle finansiële goedkeuringsproses vir kapitaalprojekte te hersien. Energex het dus 'n sagteware toepassing ontwikkel wat die finansiële gangbaarheid van hernuwingsprojekte evalueer. Hierdie navorsing sal die moontlike integrasie van geografiese inligtingstelsels (GIS) met dié van Energex se finansiële evalueringspakket demonstreer. Die resultate van hierdie studie toon dat die integrasie van GIS in die hernuwingsproses aansienlike voordele inhou, insluitende: • die effektiewe seleksie van sub-netwerke, gebaseer op pyp konnektiwiteit, • die ontdekking van verskuilde verwantskappe tussen geografies-ruimtelike alfanumeriese data en omgewingsinligting, wat besluitneming vergemaklik, en • verbeterde toetsing van voorgestelde hernuwingsopsies deur die indiepte-nagaan van geografiesruimtelike elemente.
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MONTÓRIO, JÚNIOR Italo Alves. "Alteração da composição da Matriz Elétrica a fim de mitigar a emissão de gases de efeito estufa." Universidade do Oeste Paulista, 2018. http://bdtd.unoeste.br:8080/jspui/handle/jspui/1111.
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Humanity goes through a period of great transformations. Anthropic activity, mainly in recent years, has been substantially modified the terrestrial environment. Practices which damage the Earth system, such as Greenhouse Gas (GHG) emissions, can compromise the terrestrial life. The utilization of non-renewable sources has promoted a significant increase in air pollutant emissions. It supposes that the population, now estimated at more than seven billion, is expected to reach around 10 billion people by 2050 and the global economy to triple in this period, conditions that will lead to large increases in global demand for energy. Due to this continuous and progressive increase in energy consumption, it will be necessary to generate more electricity. Therefore, there is a need of an intense analysis of the anthropic practiced activities. The hypothesis of this work is presented as the alteration of the Electric Matrix composition in order to mitigate the Greenhouse Gas emission. The present work has as objectives to study the projection of GHG emission in the Brazilian Electrical Matrix by the year 2050 using the "Calculadora Brasil 2050" application, to perform a case study of the alteration in the Electric Matrix composition of energy consumed by Instituto Federal de São Paulo, Presidente Epitácio Campus, through a photovoltaic micro power plant and the an energy efficiency program, and finally, to study the global Electrical Matrix composition and its implications on environmental issues through qualitative and quantitative documentary research of applied nature. The Brazilian Electrical Matrix is expected to have an increment in the use of photovoltaic solar energy and in energy efficiency to maintain GHG emissions in the year of 2050 at the same current levels. There was an 8.30% reduction in the consumption of the Electrical Energy (EE) acquired from the distribution network with the installation of the photovoltaic micro power plant, and it occurred a reduction of 51% in the EE consumption for lighting with the implemented energy efficiency program. The institution stopped using 1,386.78 KWh per month from non-renewable sources, which is equivalent to a reduction of 31.8%, proving the alteration in the Electric Matrix consumed by the campus. In the world, countries have a distinct relation between the use of renewable and non-renewable sources for EE generation, implicating in a possibility of classification of these countries in relation to environmental issues by the Environmental Contribution Rate (ECR). The Environmental Balance Time (EBaT) of photovoltaic panels is related to the ECR and the Energy Pay Back Time (EPBT) of the system.
A humanidade passa por um período de grandes transformações. A atividade antrópica, principalmente nos últimos anos, tem modificado substancialmente o ambiente terrestre. Práticas que lesionam o sistema do planeta Terra, como as emissões de gases de efeito estufa, podem comprometer a vida terrestre. A utilização de fontes não renováveis promoveu um acréscimo significativo nas emissões de poluentes atmosféricos. Supõe-se que a população, hoje estimada em mais de sete bilhões, chegue ao redor de dez bilhões de indivíduos em 2050 e que a economia global triplique neste período, condições que levarão a grandes aumentos na demanda global por energia. Devido a este aumento contínuo e progressivo do consumo de energia, será necessário gerar mais eletricidade. Portanto, há a necessidade de uma profunda análise das atividades antrópicas praticadas. A hipótese deste trabalho apresenta-se como a alteração da composição da Matriz Elétrica a fim de mitigar a emissão de gases de efeito estufa. O presente trabalho tem como objetivos estudar a projeção da emissão de GEE na Matriz Elétrica brasileira até o ano de 2050 utilizando o aplicativo “Calculadora Brasil 2050”, realizar um estudo de caso da alteração da composição da Matriz Elétrica da energia consumida pelo Instituto Federal de São Paulo Câmpus Presidente Epitácio por meio de uma micro usina fotovoltaica e de um programa de eficiência energética e, finalmente, estudar a composição da Matriz Elétrica mundial e suas implicações nas questões ambientais por meio de uma pesquisa documental quali quantitativa e de natureza aplicada. A Matriz Elétrica brasileira deverá ter um incremento na utilização da energia solar fotovoltaica e em eficiência energética para manter as emissões de GEE no ano de 2050 nos mesmos níveis atuais. Com a instalação da micro usina fotovoltaica ocorreu uma redução 8,30% no consumo de Energia Elétrica (EE) adquirida da rede de distribuição e com o programa de eficiência energética implantado, ocorreu uma redução de 51% do consumo de EE para a iluminação. A instituição deixou de utilizar, mensalmente, 1.386,78 KWh provenientes de fontes não renováveis, o que equivale a uma redução de 31,8%, comprovando a alteração da Matriz Elétrica consumida pelo câmpus. No mundo, os países possuem uma relação distinta entre a utilização de fontes renováveis e não renováveis para a geração de EE, implicando em uma possibilidade de classificação destes países em relação às questões ambientais pela “Environmental Contribution Tax” (ECR). O “Environmental Balance Time” (EBaT) dos painéis fotovoltaicos está relacionado com o ECR e com o “Energy Pay Back Time” (EPBT) do sistema.
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Sasser, Shawn. "The Design and Testing of a Novel Batch Photocatalytic Reactor and Photocatalyst." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6381.
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With an ever-increasing human population, the importance in having sustainable energy resources is becoming increasingly evident, as the current energy habits have brought about massive atmospheric pollution in the form of CO2 emissions, resulting in a rise in the average global temperature. To battle the effects of climate change, many alternative energy resources have been investigated. Among these, photocatalytic conversion of CO2 to renewable hydrocarbon fuels such as methane and methanol is one of the most desirable, as it provides the opportunity to utilize the sun’s energy to convert CO2 to renewable fuels. The work in this study is primarily focused on developing a batch photoreactor system to improve the integrity of photocatalytic experiments and using that system to test the performance of Er-doped solid solutions of ZnO/GaN (ZG) towards photocatalytic reduction of CO2.
To upgrade the abilities from previous photoreactor systems, a novel photoreactor was deigned in SolidWorks and fabricated in-house. The photoreactor was designed to increase surface area at the gas-solid interface, improve utilization of the light source, and promote larger mass transfer rates of reactants to the catalyst surface. These goals were accomplished by immobilizing the catalyst on a transparent porous support, incorporating a threaded mount on top of the photoreactor for mounting an interchangeable LED to illuminate the catalyst bed, and recirculating the gas mixture through a closed loop system with a compressor, respectively.
Pure and Er-doped ZG photocatalyst samples were synthesized through the nitridation of Zn/Ga/CO3 layered double hydroxide (LDH) precursors. Erbium was chosen as a dopant to potentially enhance the photocatalyst by utilizing its upconversion photoluminescence properties. The LDH precursors were synthesized using a coprecipitation method. Levels of erbium doping were varied by [Er]/[Zn] = 0, 0.025, 0.05, and 0.10. ZnO/GaN solid solutions were chosen for their low bandgap energy so that visible light, roughly 40% of the solar spectrum [1], can be used to activate the catalyst. Diffuse reflectance spectroscopic data of the pure and Er-doped ZG samples were measured and used to calculate the bandgap energy. Bandgap values of EG = 2.53, 2.52, 2.56, and 2.56 eV were obtained for the [Er]/[Zn] = 0, 0.025, 0.05, and 0.10 samples, respectively. XRD data of the LDH samples indicated the formation of Zn/Ga/CO3 LDH and the Zn(OH)2, β-Ga2O3, α-GaOOH, and ZnGa2O4 impurity phases. Moreover, the broadening of the diffraction peaks in the Er-doped LDH samples suggested Er3+ ions substituted the Ga3+ ions in the LDH structure. XRD data of the pure and Er-doped ZG samples revealed strong peaks at 2θ = 31.86, 34.37, and 36.31°, indicating the formation of a solid solution of ZnO and GaN. Additionally, peaks at 2θ = 29.27, 48.79, and 57.86° indicate the formation of the secondary phase of Er2O3 in the Er-doped samples. Consequently, it was concluded that the Er3+ ions did not go into the crystal structure of the oxynitride solid solution. These findings were supported by the SEM images revealing hexagonal nanoplates and nanoprisms that coincide with the solid solution along with additional nanostructures corresponding to the Er2O3 phase.
During photocatalytic experiments with the pure and Er-doped ZG samples, CO2, and UV light (405 nm nominal wavelength), hydrocarbon production was observed to increase with increasing [Er/Zn]. However, results from control experiments with no catalyst while varying the nominal LED wavelength and the o-ring material suggested that hydrocarbon formation was partially or entirely the result of the o-ring photochemically degrading in the presence of UV light. An o-ring comprised of a silicone material yielded zero hydrocarbon formation in the presence of UV light, while this was not the case for o-ring materials of Viton® and Kalrez®. These findings can be applied to other research groups that plan to perform photocatalytic experiments in a photoreactor with o-rings while using a UV light source.
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Tang, Wing-keung. "Redevelopment of potentially hazardous installations : a case study of the Hong Kong and China gas works at Ma Tau Kok /." [Hong Kong] : University of Hong Kong, 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13814199.
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Bisoto, Tatiana. "Preparação e caracterização de membranas cerâmicas compostas tubulares para aplicação na separação de gases." reponame:Repositório Institucional da UCS, 2014. https://repositorio.ucs.br/handle/11338/899.
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Este trabalho tem como objetivo preparar membranas compostas de α-alumina recobertas com paládio usando a técnica de deposição química electroless plating associada ao método sol-gel. Foram realizados tratamentos térmicos a 1450°C nos suportes cerâmicos em 6, 12, 18, 24 e 30 h visando verificar a influência do tempo na porosidade do mesmo. Foram preparadas membranas compostas, alumina-Pd com uma, duas e três camadas de paládio na superfície externa do suporte cerâmico, em que o suporte e as membranas foram caracterizados por: análise morfológica realizada por Microscopia Eletrônica de Varredura (MEV) e Microscopia Eletrônica de Varredura de Emissão de Campo (FESEM), porosidade avaliada pelo Método de Brunauer, Emmet e Teller (BET), Método de Barret-Joyner-Halenda (BJH) e porosimetria de mercúrio, quantificação de paládio em solução por Espectrometria de Massa com plasma indutivamente acoplado (ICP-MS) e a permeabilidade e seletividade dos gases mensurada a partir de um equipamento em escala de bancada. O aumento do tempo durante a sinterização não promoveu mudanças significativas na porosidade do suporte, mostrando que o tempo de 6 h de tratamento térmico é suficiente para atingir a menor distribuição de tamanho de poro do material. A formação da camada de paládio foi realizada sem e com a associação do método sol-gel, apresentando uma camada mais homogênea com o uso do método, no entanto a análise de ICP-MS indicou maior quantidade de metal paládio na deposição electroless plating. A análise morfológica indicou espaços vazios menores de acordo com o número de camadas formadas. O suporte cerâmico sem e com camada de paládio apresenta variação na permeabilidade aos gases N2, CH4 e CO2 nas pressões de 100 a 400 kPa e quanto mais espessa a camada de paládio formada, menor é a permeabilidade dos gases.Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2015-02-23T18:54:16Z No. of bitstreams: 1 Dissertacao Tatiana Bisoto.pdf: 546380 bytes, checksum: b684b58eaa3e2af8b355719394be7208 (MD5)
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Within this context, this work aims to prepare membranes composed of α-alumina coated with palladium using the electroless plating technique associated with the sol-gel method. To achieve the objectives of the paper, analyzes of porosity of the ceramic support with and without heat treatment of 1450°C for 6; 12; 18; 24 and 30 h, the formation of one, two and three layers of palladium on the external surface of the ceramic support, the effect of the sol-gel method, the chemical and physical properties, permeability and selectivity of the gases were performed. Morphological analysis were performed by Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscope (FESEM), the membrane porosity was evaluated by the Brunauer, Emmet and Teller (BET) theory, Barret-Joyner-Halenda (BJH) method and by mercury porosimetry, the palladium quantification in solution was given by mass spectrometry with inductively coupled plasma (ICP-MS) analysis and gas permeability and selectivity were measured by a bench scale equipment. The time increase during the sinterization did not promote representing changes in the support porosity, which shows that the 6 h time of heat treatment is sufficient to achieve the lowest porosity of the material. The palladium layer formation was realized without and with the combination of the sol-gel method, presenting a more homogeneous layer with the use of the method. However, the ICP-MS analysis indicated a greater amount of palladium deposition without sol-gel method. The morphological analysis showed smaller empty spaces according to the number of layers formed. The ceramic support without and with palladium layer showed variation in permeability to N2, CH4 and CO2 gases at pressures of 100 to 400 kPa and the higher the palladium layer formed, the smaller the gas permeability
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Er-Rbib, Hanaâ. "Conception et simulation du fonctionnement d’une unité de stockage/déstockage d’électricité renouvelable sur méthane de synthèse au moyen d’un co-électrolyseur à haute température réversible : Approches stationnaire et dynamique." Thesis, Paris, ENMP, 2015. http://www.theses.fr/2015ENMP0044/document.
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L'objectif de cette thèse est de concevoir, d'évaluer les performances énergétiques et d'étudier le comportement en régime transitoire pendant les opérations de chauffage et de démarrage d'un procédé réversible Power To Gas qui est une solution pour l'intégration des énergies renouvelables dans le mix énergétique. L'évaluation des performances énergétiques montre que 66,7% de l'énergie électrique entrante est stockée sous forme de substitut du gaz naturel et que les pertes concernent principalement les étapes de conversion en particulier la conversion AC/DC, la co-électrolyse et la méthanation. Le déstockage de l'électricité (Gas To Power) est réalisé en inversant le RSOC en mode SOFC alimenté par le gaz de synthèse (H2 et CO) produit dans un tri-reformeur. Ce procédé est autonome énergétiquement et produit de la chaleur inexploitée qui est à l'origine de sa faible efficacité de 40%. Une étude de la réponse en régime transitoire est conduite en développant des modèles dynamiques du co-électrolyseur réversible, des réacteurs et des échangeurs par le biais de deux logiciels: Matlab et Dymola. Les résultats permettent de préciser la pénalité énergétique et de revoir l'architecture du procédé prédéfinie en régime stationnaire. Plusieurs stratégies ont été étudiées afin d'optimiser le temps de démarrage et l'énergie consommée. Il s'est avéré que le RSOC est le composant qui consomme le plus d'énergie (71% de l'énergie totale) et qui nécessite le plus de temps de démarrage (60% du temps total) à cause de la quantité du gaz utilisée pour le chauffage et du temps important qu'il faut respecter afin d'assurer une augmentation en température progressive qui évite la détérioration des cellulesThe objective of this thesis is to design, evaluate the energetic performance and study the transient behavior during heating and startup operations of a reversible process Power To Gas process which is a solution for the integration of renewable electricity in the energy mix. Steady state models are first established in Aspen plus. Assessment of energetic performance shows that 66.7% of the electrical energy is stored as a Synthetic Natural Gas and the losses are caused mainly by the converting steps: the AC/DC, co-electrolysis and methanation conversions. Electricity production (Gas to Power) is performed by reversing the RSOC in SOFC mode fueled by synthesis gas (CO and H2) produced in a tri-reformer. This process is energetically autonomous and produces untapped heat which causes its 40% low efficiency. A study of the transient response during heat-up and start-up operations is conducted through the development of dynamic models of reversible co- electrolyzer, reactors and heat exchangers by using Matlab and Dymola softwares. The results allow to specify the energetic penalty and to review the architecture of predefined process in steady state. Several strategies have been studied to optimize the time and the energy consumption. It turned out that the RSOC is the slowest component (60% of total time) with the most energetic consumption (71% of total energy) because of the amount of gas used in heat-up operation and the significant time that must be respected in order to ensure an increase in temperature that prevents the cells deterioration
27
Lanjouw, Jean Olson. "The private value of patent rights : a dynamic programming and game theoretic analysis of West German patent renewal data, 1953-1988." Thesis, London School of Economics and Political Science (University of London), 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.527825.
Повний текст джерелаАнотація:
Empirical estimates of the private value of patent protection are found for four technology areas - computers, textiles, combustion engines and pharmaceuticals - using new patent renewal data of West German patents collected for the period 1953-1988. In Germany, a patentee must pay an annual renewal fee to keep his patent in force. Two dynamic discrete choice models of optimal renewal decisions are developed and used. in conjunction with observed hazard proportions and renewal fee schedules, to estimate the returns to protection. Differences in value across technology, nationality of inventor and time are explored both non-parametrically and parametrically within a deterministic framework. A stochastic formulation of the model, which allows both for learning about the innovation and market and for the possibility of infringements, is estimated using a minimum distance simulation estimator. The evolution of the distribution of returns over the life of a group of patents is calculated for each technology. Results indicate that learning is completed after 6 years, that obsolescence is rapid, and that the distributions of patent value are very skewed. Research and development (R&D) expenditures for each technology area are calculated and patent protection as an implicit subsidy to investment in R&D is discussed. Patent protection is valuable only when there are potential competitors for the use of an innovation. Patent rights must be defended. A game theoretic analysis of litigation explores how these facts influence the decision whether to apply for and keep a patent in force and, in tum, the relationship between the distribution of patent value and that of the underlying innovation. Implications for renewal behaviour are derived from the analysis and the data suggests that the level of potential competition does affect the value of protection. Consideration is given to how these findings bear on the interpretation of empirical estimates of patent value as indicators of innovation.
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Posen, I. Daniel. "Fuel, Feedstock, or Neither? – Evaluating Tradeoffs in the use of Biomass for Greenhouse Gas Mitigation." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/712.
Повний текст джерелаАнотація:
Biomass is the world’s largest renewable energy source, accounting for approximately 10% of global primary energy supply, and 5% of energy consumed in the United States. Prominent national programs like the U.S. Renewable Fuel Standard incentivize increased use of biomass, primarily as a transportation fuel. There has been comparatively little government support for using biomass as a renewable feedstock for the chemical sector. Such asymmetry in incentives can lead to sub-optimal outcomes in the allocation of biomass toward different uses. Greenhouse gas reduction is among the most cited benefits of bioenergy and bio-based products, however, there is increasing controversy about whether increased use of biomass can actually contribute to greenhouse gas emission targets. If biomass is to play a role in current and future greenhouse gas mitigation efforts its use should be guided by efficient use of natural and economic resources. This thesis addresses these questions through a series of case studies, designed to highlight important tradeoffs in the use of biomass for greenhouse gas mitigation. Should biomass be used as a fuel, a chemical feedstock, or neither? The first case study in this thesis focuses on the ‘fuel vs feedstock’ question, examining the greenhouse gas implications of expanding the scope of the U.S. Renewable Fuel Standard to include credits for bioethylene, an important organic chemical readily produced from bioethanol. Results suggest that an expanded policy that includes bioethylene as an approved use for ethanol would provide added flexibility without compromising greenhouse gas targets – a clear win scenario. Having established that bioethylene based plastics can achieve similar greenhouse gas reductions to bioethanol used as fuel, this thesis expands the analysis by considering how the greenhouse gas emissions from a wider range of bio-based plastics compare to each of the main commodity thermoplastics produced in the U.S. The analysis demonstrates that there are large uncertainties involved in the life cycle greenhouse gas emissions from bio-based plastics, and that only a subset of pathways are likely to be preferable to conventional plastics. The following chapter then builds on the existing model to compare the greenhouse gas mitigation potential of bio-based plastics to the potential for reducing emissions by adopting low carbon energy for plastics production. That chapter concludes that switching to renewable energy across the supply chain for conventional plastics energy cuts greenhouse gas emissions by 50-75%, achieving a greater reduction, with less uncertainty and lower cost, than switching to corn-based biopolymers – the most likely near-term biopolymer option. In the long run, producing bio-based plastics from advanced feedstocks (e.g. switchgrass) and/or with renewable energy likely offers greater emission reductions. Finally, this thesis returns to the dominant form of policy surrounding biomass use: biofuel mandates. That study takes a consequential approach to the ‘fuel or neither’ question. Specifically, this work examines how petroleum refineries are likely to adjust their production in response to biofuel policies, and what this implies for the success of these policies. The research demonstrates that biofuel policies induce a shift toward greater diesel production at the expense of both gasoline and non-combustion petroleum products. This has the potential to result in an increase in greenhouse gas emissions, even before accounting for the emissions from producing the biofuels themselves.
29
Filho, Francisco do Espirito Santo. "Estimativa do aproveitamento energético do biogás gerado por resíduos sólidos urbanos no Brasil." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/86/86131/tde-16022014-170905/.
Повний текст джерелаАнотація:
Esta dissertação visa estimar o potencial de energia elétrica do biogás, conhecido também como gás de aterro, gerado por resíduos sólidos urbanos (RSU) no Brasil. A estimativa foi aplicada para todos os 5.565 municípios do Brasil. O método utilizado para estimar a geração de biogás foi o IPCC 2000 (First Order Decay - FOD), pois leva em consideração inúmeros parâmetros, como a composição da matéria orgânica no aterro, teor de umidade do lixo, grau de compactação, temperatura no interior do aterro. Adicionalmente, este método é o mais difundido mundialmente e é o mesmo método utilizado para inventários de Gases de Efeito Estufa no Brasil, permitindo, dessa forma, comparações entre os estudos. No método, foram empregados os dados dos censos do IBGE 1970, 1980, 1991, 2000, 2010 de forma a representar fielmente o crescimento populacional e possibilita estimar a quantidade de resíduos sólidos gerados para todos os anos estudados. No estudo, foram analisados três cenários distintos representando diferentes tendências na gestão de resíduos no Brasil (cenários de referência, otimista e pessimista). O potencial elétrico do biogás no Brasil de acordo com o Cenário de referência para 2013 é de 983 MW, representando 1,6 % da potência elétrica instalada atual e para o ano de 2020, o potencial é de 1.602 MW. Concluindo o estudo, foram realizadas análises financeira e de sensibilidade em três diferentes projetos para avaliação da viabilidade de cada projeto.This dissertation aims to estimate the potential for energy recovery from landfill gas through municipal solid waste (MSW) in Brazil. The survey was carried out in all 5,565 municipalities in Brazil. The used method to estimate the generation of landfill gas was the IPCC 2000 (First Order Decay - FOD) because it takes into account several parameters, such as: the type of organic matter, the waste moisture content, degree of compaction and temperature inside the landfill. Additionally, this method is the most widespread in the world and it is the same method used in greenhouse gases inventories in Brazil, thus allowing comparisons between these studies. In the method, data from national census of 1970, 1980, 1991, 2000, 2010 was used in order to accurately represent the population growth and allows estimating the amount of solid waste generated in every year. The study analyzed three different scenarios representing different trends in the solid waste management in Brazil (reference, optimistic and pessimistic scenarios). The electrical potential of landfill gas in Brazil (in the reference scenario) in 2013 is 983 MW, representing 1.6% of the current installed capacity and for 2020, the electrical potential is 1,602 MW. Concluding this study, a financial and sensitivity analysis as carried out on three different projects to evaluate the feasibility of each project.
30
Topcuoglu, Ahmet. "Design and Testing of a Reciprocating Wind Harvester." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7971.
Повний текст джерелаАнотація:
Renewable energy sources are vital to reduce dependence on fossil fuels that are harmful for the environment and release greenhouse gases causing global warming. Wind energy is a natural source of energy that is abundant in the environment. While wind turbines are most popular, convenient, and used to harvest energy at large scales, there have been recent studies focusing on harvesting energy from the wind for microdevices. Such micro wind energy harvesters can decrease dependence on batteries.
In this study, a novel, framed flag micro wind harvester was designed and tested, and its behavior at three different wind speeds was experimentally examined in a wind tunnel. The main purpose of this study is to determine the geometric and wind speed conditions under which regular flapping occurs in the flag material.
A high-speed camera was used to visualize the motion of the harvester at different wind speeds and at various parametric ratios of the flag material length to the frame length. The movies taken by the camera are analyzed using Image J software to find the flapping frequency, flapping angle, and the amplitude. Nondimensional parameters such as the Re number and St number also are calculated.
This study finds that parametric ratios of 1.1 and 1.2 with the medium wind speed condition of 5 m/s are optimal flapping conditions. These optimal conditions would conveniently allow the use of piezoelectric material as the flag material in order to harvest energy. Further, an advantage of this novel design over previous designs is that the wind harvester naturally aligns with the wind direction and is thus omnidirectional.
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Silva, Cinthia Rubio Urbano da 1982. "Balanço de energia e das emissões de gases de efeito estufa da cadeia produtiva do etanol brasileiro." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263795.
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Orientador: Arnaldo Cesar da Silva WalterDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: A busca por combustíveis que substituam fontes fósseis tem incentivado a produção de biocombustíveis, especialmente para o setor de transporte. O objetivo deste trabalho é fazer os balanços de energia e das emissões de gases de efeito estufa do etanol derivado da cana de açúcar produzido no Brasil. Na dissertação, foram também avaliadas as emissões de gases de efeito estufa associadas à mudança do uso do solo devido à expansão de áreas cultivadas com cana (impacto direto), bem como os fatores relacionados à distribuição do etanol para uso no Brasil e na Europa. Um cenário de uso do etanol em substituição ao biodiesel (B3) nas etapas de transporte da cana e distribuição do etanol é igualmente analisado. Os balanços abrangem as etapas de produção da cana de açúcar, transporte até as usinas, produção, distribuição e uso final do etanol anidro. A análise é realizada separadamente para cada estado brasileiro da região Centro-Sul que tem significativa produção de etanol (Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, São Paulo e Paraná). A base de dados, obtida na literatura, reflete as condições de produção no Brasil no período de 2005 a 2007. Os resultados apontam balanços favoráveis para o etanol quando usado no Brasil. Para a produção no Brasil e uso na Europa, os balanços resultaram menos favoráveis. Quando o uso do etanol passa a ser feito em substituição ao B3, os balanços são significativamente mais positivos. Os resultados levam à conclusão de que melhores balanços de energia e das emissões de gases de efeito estufa dependem basicamente do modal de transporte para distribuição do etanol, práticas agrícolas adotadas (plantio direto ou convencional) tanto para produção da cana quanto da biomassa que foi substituída, método para cálculo das emissões de óxido nitroso associadas à aplicação de fertilizantes nitrogenados, além das produtividades agrícolas e industriais.
Abstract: The search for fuels that replace fossil resources have stimulated biofuel production, especially for the transportation sector. The goal of this work is to do balances of energy and of greenhouse gas emission of ethanol from sugar cane produced in Brazil. In this dissertation, greenhouse gas emission associate to land use change due to expansion of areas cultivated with sugar cane (direct impact), as well as how the factors related to distribution of ethanol for use in Brazil and for use in Europe, were also evaluated. Scenery of ethanol use in replace to biodi esel(B3) in the transportation of sugar cane and distribution of ethanol stages is equally ana lyzed.The balances embrace the stages of the sugar cane production, transportation until the mill, production, distribution and end use of the anhydrous ethanol. The analysis is done separately for each Brazilian State of the Centre-South region that has great ethanol production (Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, São Paulo and Paraná). The data base, achieved in literature, reflects the conditions Brazilians of production in the period from 2005 to 2007. The results show favorable balances for the ethanol when it is used in Brazil. In the case of production in Brazil and consumption in Europe, the balances resulted less favorable. When the ethanol use starts to be done in replace to B3, the balances are remarkably more positive. The results lead to the conclusion that better energy and greenhouse emission balance depend basically on: i) the means of transportation to distribute the ethanol; ii) agricultural management adopted (direct or conventional planting) as for sugar cane production as for biomass production that was replaced; iii) the method to calculate the nitrous oxide emission from application of fertilizer with nitrogen, besides agricultural and industrial productions.
Mestrado
Planejamento de Sistemas Energeticos
Mestre em Planejamento de Sistemas Energéticos
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PARIS, ALEXANDRE G. "Redução das emissões de gases de efeito estufa listados no protocolo de Quioto pelo aproveitamento do gás gerado em aterros sanitários utilizando células a combustível de óxido sólido: estudo de caso do aterro municipal de Santo Andre-SP-Brasil." reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11582.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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Rezaie, Behnaz. "Analysis of alternative energy options for buildings." Thesis, UOIT, 2009. http://hdl.handle.net/10155/40.
Повний текст джерелаАнотація:
The importance of utilizing different types of energy and their technical application
is discussed. Awareness around the globe about the world energy crisis and its critical
environmental condition has put more emphasis on the use of renewable energies in
every corner of life. It is a well‐known fact that global warming, inefficient use of energy
and greenhouse gases are damaging the environment, species and human life drastically.
These issues will be discussed in recently conducted research.
To address the crucial state of our environment, two simultaneous scenarios are
considered. Initially, energy conservation and the switch to a low carbon/no carbon fuel
are studied. As for energy conservation in buildings, smart methods in the use of energy in
buildings are discussed. Based on different research reported, humans must change their
attitude toward the use of resources, and in particular, be conscientious about energy
consumption. Next, renewable energy promises a suitable alternative to energy needs in
this century, and the best means to overcome the environmental issue and energy crisis is
discussed. The practical methods of calculation for solar technology equipment, ground
source heat pumps, and wind turbines are explained. In the application part of the study,
four buildings are chosen as case studies; two of them from residential sectors, one is a
commercial/institutional building, and the fourth is an industrial building. A ground source
heat pump for heating and cooling, a solar water heater for heating space or hot water,
and a photovoltaic panel for generating electricity are designed for the case studies. Even
projects under hybrid systems combined from two technologies are designed. 36 different
energy options are calculated for the four case studies. Results show that if a target is
reducing CO2 emissions, what systems are the best. In contrast, when decision making is
based on budget, what system is the first choice? Not only are technology, environmental
protection and cost the main parameters for deciding on renewable technologies, but so
are reliability, installation, maintenance and ease of use. Hence, renewable energy
systems are categorized based on a broad vision.
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Xavier, Beatriz Helene [UNESP]. "Aspectos termodinâmicos, ecológicos e econômicos de sistemas de cogeração com motores de combustão interna operando com gás natural, biogás e gás de síntese." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/144327.
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Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP)
A preocupação com o meio ambiente e com a qualidade do ar têm sido crescente e objeto de diversos estudos. Quanto maior a densidade populacional, maior a necessidade de consumo de energia e consequentemente, maiores os índices de emissões de poluentes. Neste sentido, é essencial a procura por novas fontes e sistemas mais eficientes de geração de energia, a fim de reduzir os níveis de poluição, diminuir o efeito estufa sobre o planeta, e, principalmente, reduzir a dependência de petróleo na matriz energética mundial. Partindo deste conceito e considerando aspectos técnicos, econômicos e ecológicos, neste trabalho analisam-se três casos de cogeração utilizando motores de combustão interna (MCI) operando com gás natural em comparação com biogás e gás de síntese (syngas), ambos provenientes da biomassa. São aplicadas metodologias de pesquisadores renomados, com o objetivo de determinar a eficiência de geração de eletricidade, a eficiência de geração de calor e a eficiência global dos sistemas, e ainda como parte da análise técnica, determinam-se índices de correlação entre a produção térmica e a potência elétrica dos motores, tornando previsível a capacidade de produção de água quente, vapor e água gelada, dependendo da capacidade elétrica do motor a ser utilizado na implantação de sistemas de cogeração. São determinados os custos de geração de eletricidade e calor, período de retorno dos investimentos e posteriormente são estudadas as emissões de CO2, NOx, SOx, MP e o CO2 equivalente para a determinação do indicador de poluição e da eficiência ecológica dos sistemas de cogeração considerados nesta dissertação. Conclui-se com o estudo realizado que os biocombustíveis são uma importante fonte energética que vem ganhando espaço dia a dia. Na análise ambiental, o gás natural perdeu em eficiência ecológica tanto para o biogás como para o gás de síntese, e a análise energética comprovou que não há grandes perdas na utilização de biocombustíveis em substituição ao gás natural. No aspecto econômico, o biogás demonstrou-se como o mais rentável frente aos combustíveis estudados, apresentando rapidez no retorno dos investimentos e baixo custo de produção elétrica e térmica.
The concern with the environment and air quality has increased and subjected to several studies. The higher the population density, the greater the need for energy consumption and therefore higher pollutant emission rates. In this regard, the search for new sources and more efficient systems for power generation is essential in order to reduce pollution levels and the greenhouse effect on the planet, and, most importantly, reduce dependence on oil in the global energy matrix. Based on this concept and considering the technical, economic and ecological aspects, this paper analyzes three cases of cogeneration using internal combustion engines (ICEs) operating with natural gas in comparison with biogas and synthesis gas (syngas), both stemming from biomass. Methodologies from renowned researchers are applied, with the aim of determining the efficiency of electricity generation, heat generation efficiency and the overall efficiency of the systems; furthermore, as part of the technical analysis, we determine correlation coefficients between the thermal production and the power capacity of the engine, making it possible to predict hot, steam and cold water production capacities, depending on the engine power capacity used in the implementation of the cogeneration system. We determine the costs of generating electricity and heat, the payback period and then CO2, NOx, SOx, MP and equivalent CO2 emissions are studied in order to determine the pollution indicator and ecological efficiency of cogeneration systems considered in this thesis. From this study we conclude that the biofuels are an important energy source which is becoming increasingly popular. In the environmental analysis, the natural gas was less ecologically efficient than both the biogas and the syngas, and the technical analysis showed that there are not great losses when using biofuels in place of the natural gas. In the economic analysis, the biogas was the most feasible in comparison with the natural gas and the syngas, with a short payback period and low power and thermal production costs.
PRH/ANP: 2010.4698-0
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Grisoli, Renata Patricia Soares. "Comparação das emissões de gases de efeito estufa no ciclo de vida do etanol de cana-de-açúcar e os critérios da diretiva européia para energias renováveis." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/86/86131/tde-10082011-152907/.
Повний текст джерелаАнотація:
A busca por energias renováveis no setor de transportes fez com que os biocombustíveis se destacassem. No entanto, a preocupação com a sustentabilidade na produção dessas fontes alternativas motivou diversas iniciativas na proposição de critérios com o intuito de reduzir os impactos ambientais e garantir os benefícios desses biocombustíveis, principalmente relacionados à redução da emissão de gases de efeito estufa (GEE). Países como os Estados Unidos e membros da União Européia criaram legislação específica com a finalidade de direcionar esses critérios tanto para a produção interna, quanto para a importação dessas fontes de energia. A principal metodologia presente nessas legislações e utilizada na caracterização da cadeia dos biocombustíveis é a Avaliação do Ciclo de Vida (ACV). Este trabalho teve por objetivo comparar os resultados da Diretiva Européia para Energias Renováveis, para as emissões de GEE no ciclo de vida do etanol de cana-de-açúcar, com os estudos nacionais de maior relevância, a fim de verificar se há diferenças significativas entre eles. A partir desta análise, foi possível concluir que há diferenças entre os estudos, principalmente relacionadas à etapa agrícola, mas que, no entanto, foram pontuais, sendo balanceadas entre os processos e atingindo, em sua maioria, um resultado final semelhante de emissões de GEE entre eles. Neste trabalho também foram discutidas as incertezas existentes nos estudos de ACV do etanol de cana-de-açúcar, principalmente relacionadas às emissões pelo uso de fertilizantes nitrogenados e a mudança indireta do uso do solo. Além disso, a partir das contribuições de instituições brasileiras no estabelecimento de diretrizes para que o etanol fosse aceito como importante combustível na redução dos GEE, este trabalho apresentou a relevância em se discutir as normativas internacionais de sustentabilidade, para que os critérios não sejam considerados como mais uma barreira protecionista ao comércio de biocombustíveis.The search for renewable energy to be used in the transportation sector emphasized the role of biofuels as an alternative to fossil fuels. However, concerns about the sustainability in the production of alternative sources stimulated several initiatives aiming to reduce environmental impacts and ensure the benefits of biofuels, mainly related to the reduction of greenhouse gases emission (GHGs). In order to address such question, countries such as United States and European Union members have designed specific legislation establishing social and environmental criteria for domestic production and imports of biofuels. The main methodology adopted in these laws and used to characterize the biofuels chain is the Life Cycle Assessment. Thus, this study aimed to compare the results on GHG emission of the Renewable Energy Directive (RED) in the lifecycle of sugar cane ethanol to most relevant studies developed within the country in order to verify differences between them. From the analysis, it was concluded that there were differences, mainly related to the agricultural phase, but they were specific, and balanced between the processes; resulting, in most cases, in quite similar final GHG emissions. In this work, it were also indicated the uncertainties in sugar cane ethanol LCA studies, mainly associated to emissions due the use of nitrogen fertilizer and indirect land use change. Furthermore, based on the contributions of Brazilian organizations in establishing guidelines for the acceptance of ethanol as an important fuel to GHG emissions reduction, this study showed the relevance of discussing international standards of sustainability, considered another protectionist barrier to biofuels trade.
36
Van, Oss Eric J. "Sustaining Rural Economies with Wind Development." Scholarship @ Claremont, 2010. http://scholarship.claremont.edu/cmc_theses/56.
Повний текст джерелаАнотація:
This paper discusses the effects of wind development in rural areas. Areas of focus include: direct job creation, indirect job creation, tax revenue and government policies. The effects of state and federal renewable energy policies are discussed and well as the impacts to rural economies.
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Jaini, Rajiv. "Mass-transfer correlations for the dual bed colloidal suspension reactor." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50210.
Повний текст джерелаАнотація:
To meet the growing energy world demands, and in conjunction, lower CO2 production levels, near zero emission energy sources must be pushed to the forefront as alternatives to fossil fuels. Photoelectrochemical (PEC) cells are a potential alternative to fossil fuels and have recently generated much interest because of their potential to electrolyze water into hydrogen fuel from sunlight. But in order to be competitive with fossil fuels, understanding the mass-transfer limitations in PEC systems is critical. This work focuses on the addressing the mass-transfer limitations in a conceptually novel PEC cell reactor, the Dual Bed Colloidal Suspension Reactor (DBCSR).
Mass-transfer correlations for the DBCSR are presented. The correlations are based on experimental data obtained using two fabricated diffusion cells. The working correlation representative of both cells is given.
An analysis of the orientation of the gas sparger suggests that the transport phenomena in both cells is not the same, and therefore using two correlations to represent similar systems is justified. An energy analysis is presented that shows that gas sparging is a low energy consumption option to mitigate mass-transfer limitations. Future work is suggested for better understanding the mass-transfer behavior in the DBCSR.
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Chaves, Luiz Inácio. "Microgeração de energia elétrica com gás de síntese de um gaseificador concorrente utilizando Itaúba mazilaurus." Universidade Estadual do Oeste do Parana, 2012. http://tede.unioeste.br:8080/tede/handle/tede/834.
Повний текст джерелаАнотація:
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Previous issue date: 2012-09-17The use of biomass as energy source is one of the most promising, because it contributes to reduce emissions of carbon dioxide in the atmosphere and allow the decentralized energy generation. Gasification is a technology of processing biomass energy into a gaseous biofuel of low calorific value. The gas can be used in Otto cycle engine for power generation in isolated communities. This study evaluated the capacity of the gasification gas in a fixed bed gasifier downtraft of two stages, the wood consumption, the efficiency of the gasifier and the gas consumption and efficiency in apower-generator Otto cycle. The gasifier use was a TERMOQUIP brand, model CD 40. The evaluated power-generator was a BRANCO brand, direct injection and power of 13 cv coupled to an electric generator of 5.5 cv. The gasification gas was injected into the engine mixed with the intake air. The generator was subjected to loads ranging from 0.5 kW to 2.5 kW, with the aid of a bank of electrical resistances. The production of gas from the gasifier and gas consumption by the motor were measured by means of a gasometer. The average gas production resulting from the gasification of wood presented during testing was 14.28 m³ hˉ ¹. Wood consumption averaged 5.61 kg hˉ ¹. The average yield of gas per unit weight was approximately 2.55 m3kgˉ ¹. The gasification efficiency averaged 57.2%. When fed with synthesis gas, the output voltage of the generator was kept within the standards established by Companhia Paranaense de Energia (Copel, 2008), varying only between 221 and 223 V. For tests with the power-generator the best condition occurred for the highest load, 2.5 kW, where the gas consumption was about 10.6 m³ hˉ ¹ and specific fuel consumption of 4.8 m³ kWhˉ¹. For this condition, the average specific fuel consumption of equivalent wood was 1.9 kg kWh ˉ ¹ and the overall efficiency of power-generator was about 16.6%.
O uso da biomassa como fonte de energia é uma das formas mais promissoras, pois contribui para a redução das emissões de dióxido de carbono na atmosfera e possibilita a geração descentralizada de energia. A gaseificação é uma tecnologia de transformação energética da biomassa num biocombustível gasoso de baixo poder calorífico. O gás pode ser utilizado em motor ciclo Otto para geração de energia elétrica em comunidades isoladas. Este trabalho avaliou a capacidade de produção de gás de gaseificação em um gaseificador concorrente de leito fixo de dois estágios, o consumo de madeira, a eficiência do gaseificador, a eficiência e o consumo de gás num motor-gerador ciclo Otto. O gaseificador utilizado foi da marca TERMOQUIP, modelo CD 40. O motor-gerador avaliado foi da marca BRANCO, com injeção direta e potência de 13 cv acoplado a um gerador elétrico de 5,5 cv. O gás de gaseificação foi injetado no motor misturado com o ar de admissão. O gerador foi submetido a cargas que variaram entre 0,5 kW e 2,5 kW, com o auxílio de um banco de resistências elétricas. A produção de gás do gaseificador e o consumo de gás pelo motor foram medidos por meio de um gasômetro. A produção de gás média resultante da gaseificação de madeira apresentada durante os testes foi de 14,28 m³ hˉ¹. O consumo de madeira apresentou uma média de 5,61 kg hˉ¹. A média de rendimento de gás por unidade de massa foi de aproximadamente 2,55 m3 kgˉ¹. A eficiência de gaseificação média foi de 57,2 %.Quando alimentado com gás de síntese, a tensão de saída do gerador se manteve dentro dos padrões estabelecidos pela Companhia Paranaense de Energia (COPEL, 2008), variando somente entre 221 e 223 V. Em relação aos testes com o motor-gerador, a melhor condição ocorreu para a maior carga, 2,5 kW, onde o consumo de gás foi cerca de 10,6 m³ hˉ¹ e o consumo específico de combustível de 4,8 m³ kWhˉ¹. Para essa condição, a média de consumo específico equivalente de madeira foi de 1,9 kg kWhˉ¹e a eficiência global do motor-gerador foi de 16,6 %.
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Mihailovic, Nemanja. "A Cost Benefit Analysis of Using a Battery Energy Storage System (BESS) Represented by a Unit Commitment Model." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7548.
Повний текст джерелаАнотація:
This thesis aims to provide a general overview of a cost and benefit analysis of incorporating a battery energy storage system within unit commitment model.
The deregulation of the electricity market in the U.S. has only been around for the last two decades. With renewable energy and energy storage systems becoming less expensive, a decentralized market scheme is becoming more popular and plausible. The scope of this work is to provide a fundamental understanding of unit commitment and a cost analysis of applying a battery energy storage system to an already established power system.
A battery energy storage system (BESS) was placed within a unit commitment schematic and modeled for a 7 day/168 hour forecast. Three models were generated, two with and one without the battery energy storage device (BESS). The comparison between the three systems was conducted to produce a visual economic justification to the feasibility of a BESS.
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De, Saint Jean Myriam. "Étude énergétique et évaluation économique d'une boucle de stockage - déstockage d'énergie électrique d'origine renouvelable sur méthane de synthèse à l'aide d'un convertisseur électrochimique réversible SOEC - SOFC." Thesis, Paris, ENMP, 2014. http://www.theses.fr/2014ENMP0051/document.
Повний текст джерелаАнотація:
Ces travaux visent à évaluer la possibilité technique, la performance énergétique et la compétitivité économique d'un procédé Power-to-SNG dans le contexte actuel et à déterminer si la réversibilité en mode Gas-to-Power est pertinente tant énergétiquement qu'économiquement, ce type de procédé étant proposé comme une solution à l'intégration des ressources renouvelables dans le mix énergétique. Les grandes étapes identifiées pour le procédé Power-to-SNG sont l'électrolyse de l'eau pour la production d'hydrogène, l'hydrogénation du dioxyde de carbone pour la production de méthane et une étape de mise aux spécifications pour satisfaire aux exigences de composition pour l'injection sur le réseau de gaz naturel. La technologie retenue pour l'électrolyse est celle des cellules à oxydes solides SOEC s'appliquant à la vapeur d'eau. L'étude énergétique du procédé Power-to-SNG réalisée par simulation avec ProsimPlus 3 montre que le couplage thermique entre la méthanation et l'électrolyse de la vapeur d'eau à haute température est pertinent, l'efficacité du procédé atteignant 75,8 % sur PCS. Concernant le procédé Gas-to-Power, il est choisi de fonctionner en pression afin de mettre en œuvre des cycles thermodynamiques complémentaires. Le choix d'alimenter la pile à combustible en hydrogène pur pour des aspects de réversibilité conduit à des limitations sur l'efficacité énergétique du procédé qui, au mieux, vaut 44,6 %. L'analyse économique des procédés Power-to-SNG et réversible est basée sur les résultats de simulations et fait appel à des performances électrochimiques observées lors de travaux expérimentaux sur monocellule avec pour point de fonctionnement un fort taux de conversion à la tension thermoneutre. Cela permet de proposer un coût actualisé du SNG produit par le procédé Power-to-SNG et un coût de l'électricité produite par le procédé réversible en considérant un couple performance électrochimique - valeur de dégradation associée cohérent et en accord avec une conduite industrielle. L'investissement et le coût d'exploitation de ces installations sont importants, conduisant à coût actualisé de l'électricité restituée au réseau électrique élevé, cela étant accentué par l'investissement supplémentaire dû à la fonction Gas-to-Power à l'installation Power-to-SNGThe present work focuses on a Power-to-SNG process, especially on its energy efficiency and its economic competitiveness in the current context. It also aims at determining if the reversibility with a Gas-to-Power working mode is interesting from energy and financial considerations. The main steps required into a Power-to-SNG process, identified thanks to a review of the state of the art, are steam electrolysis for hydrogen production, followed by methane production thanks to the Sabatier reaction and a final step of gas purification to meet the composition requirements for gas network injection. Here, electrolysis is led into solid oxide cells. Power-to-SNG process simulations, led with ProsimPlus 3, indicate that the thermal coupling between methanation and the generation of steam to feed the electrolyzer is pertinent, the process energy efficiency achieving 75.8%. Concerning the Gas-to-Power process, its solid oxide fuel cell is pressurized to use additional thermodynamic cycles. The fuel cell is fed with pure hydrogen stream due to reversibility considerations, this limiting the energy efficiency, which highest value here is evaluated at 44.6%. The economic analysis includes experimental based data concerning electrochemical performances and degradation. They are obtained on a commercial cell tested at the thermoneutral voltage with a high steam conversion rate, these conditions being close to what can be expected for industrial process. They are used to calculate the levelized cost of the SNG produced by the Power-to-SNG process and the levelized cost of electricity produced by the reverse process. Investment and operating cost of these processes are important, leading to a high levelized cost of electricity. In the conditions of this study, adding the Gas-to-Power working mode to a Power-to-SNG process is not economically pertinent
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Wittmann, Douglas. "A indústria de energia elétrica no Brasil e o desenvolvimento sustentável: uma proposta para o horizonte 2050 à luz da teoria de sistemas." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/106/106131/tde-19052015-082550/.
Повний текст джерелаАнотація:
Há um cenário de agrave na indústria de energia elétrica no Brasil, por escassez de energia afluente na produção hídrica, exigindo maior acionamento térmico. Para o futuro, usinas predominantemente a fio dágua, que estão sendo inseridas, estarão pronunciando ainda mais essa necessidade. Por força da estruturação térmica, sobrarão mais emissões de gases de efeito estufa - GEEs e consumo de recursos fósseis por unidade de energia elétrica produzida. Este estudo visa testar a possibilidade de construção de um cenário futuro, eleito 2050, de fornecimento de energia elétrica no país, balizado na aceleração do uso das fontes renováveis, premissa postulada como alinhamento à busca de desenvolvimento sustentável para o país. É utilizada a pesquisa, análise e síntese, com abordagem sistêmica, e aplicação de indicadores eleitos fundamentais para alcance do objetivo. São sistematizados dados e informações existentes em diferentes tipos de documentos elaborados por autores e organizações nacionais e internacionais, e nos planos governamentais de expansão da produção de energia elétrica. A partir do referencial teórico metodológico adotado, os resultados obtidos demonstram que é possível estabelecer um planejamento de longo prazo baseado no uso renovável dos recursos de que o país dispõe, com menores pressões socioambientais, consumos de fósseis, e emissões de gases de efeito estufa, por unidade de energia produzida. São obtidas maiores participações de fontes renováveis com menor participação da fonte hídrica, e menores participações de emissões de gases de efeito estufa e de consumo de óleo combustível. Sem incorrer em aumento nos custos de produção. Resulta um sistema descentralizado, híbrido, com maior expansão das fontes térmicas renováveis, eólica e solar, maior participação de produção independente cogeração, autoprodução, e geração distribuída e menor carga na rede de transmissão, comparativamente ao cenário atual.There is an aggravated prospect in the Brazilian electric energy industry, due to a shortage of affluent energy in the hydric production, requiring a greater thermal use. For the future, the insertion of hydroelectric power plants predominantly without reservoirs will make this need even more evident. Due to the thermal structuring, there will be more emissions of greenhouse gases (GHGs) and consumption of fossil resources per unit of electric energy produced. This study aims to test the possibility of building a future setting, elected 2050, of electric energy supply in the country, beaconed on the acceleration of the use of renewable sources, premise postulated in alignment with the pursuit of sustainable development for the country. The research, analysis and synthesis is adopted, with a systemic approach, and applying the indicators elected as paramount to reach the goal. Data and information from different types of documents produced by international and national authors and organizations as well as governmental plans of expansion of electric energy production were systematized. From the theoretical and methodological framework adopted, the results obtained have shown that it is possible to establish a long term plan, based on the use of the available resources, with decreased social and environmental pressure, fossil consumption, and emission of GHGs per unity of energy produced. A greater participation of renewable sources is achieved, while the participation of hydric sources, the emissions of GHGs and consumption of oil-fuels are reduced. There is no increase in the production costs. The result is a decentralized, hybrid system with larger expansion of renewable thermal, wind and solar sources, larger participation of independent production co-generation, auto-generation and distributed generation and a diminished load on the transmission network, compared to the current scenario.
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Ngwenya, Mpendulo Hilary Farai. "Sustainability use of information and communication technologies: a case study of an asset management company." University of Western Cape, 2013. http://hdl.handle.net/11394/3935.
Повний текст джерелаАнотація:
Magister Commercii (Information Management) - MCom(IM)The problem of global warming has triggered a number of environmental initiatives aimed at mitigating climate change, many of which are driven at governmental level - although private organisations have also taken the initiative. The organisation under study - hereafter referred to as “Company-A” - is one such organisation which has taken strides in incorporating environmental initiatives in its business processes. Company-A is a South African based asset management organisation which has seen rapid growth in its business operations and consequently the number of its employees. This growth has necessitated the need for a new office building. At the commencement of this study the organisation was in the process of planning for a new office building to accommodate its growth. The senior management of Company-A recognised the importance of implementing environmentally friendly practices at the new office building, and sought the services of a sustainability consultancy firm to assist in the planning for the new office building. This study was necessitated by the fact that despite the company’s recognition of the importance and need to implement environmentally friendly processes within its business processes, there was a lack of understanding or appreciation of how ICT could be used in an environmentally friendly and sustainable manner in its new office building. With this problem in mind - the researcher - in consultation with the organisations’ new office building project manager and research supervisor, formulated a research question which was continuously refined until such a point that it was clear. It was envisaged that a research study to answer the research question: How can Information and Communication Technologies (ICTs) be used to support environmental sustainability in an organisation? - would provide insight on how the organisation’s top management could deal with the aforementioned problem. The primary purpose of the study was to assist Company-A management in making informed decisions regarding sustainability ICT use, the research can also be used as a foundation in the formulation of the organisation’s “green” ICT strategies and policies. The main research question was divided into smaller sub questions to give structure, clarity and direction in addressing the main research question. These sub questions were in turn used to formulate the research objectives which set the goals and boundaries of this study.
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Hansen, Elizabeth R. "Reforestation, Renewal, and the Cost of Coal: Opposing a Manichean Worldview in Central Appalachia." Scholarship @ Claremont, 2015. http://scholarship.claremont.edu/pomona_theses/132.
Повний текст джерелаАнотація:
Surface coal mining is a major form of land change and environmental degradation in Central Appalachia. Traditional mine reclamation iresults in unmanaged, unproductive grasslands that fail to mitigate many of the environmental costs of coal mining and are of minimal use to communities. Forestry reclamation is an alternative reclamation tactic that has the potential to address both environmental and socioeconomic concerns in Central Appalachia. A case study of Laurel Fork Mine in Eastern Kentucky is included.
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Ávila, Márcio Turra de. "Estudo de motor de combustão interna, do Ciclo Otto, movido a etanol previamente vaporizado." Universidade de São Paulo, 1994. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-09102015-153544/.
Повний текст джерелаАнотація:
O etanol (álcool etílico) tem sido cada vez mais estudado e testado como combustível alternativo para substituição do uso de alguns derivados de petróleo em motores de combustão interna. O presente trabalho procura abordar o emprego do etanol na forma vaporizada em motores do ciclo Otto, objetivando a obtenção de melhores níveis de rendimento térmico total. Deste modo, um motor para teste de octanagem (motor CFR) foi equipado com um vaporizador de álcool instalado no coletor de escapamento, e após uma série de ensaios, várias análises puderam ser feitas. Essas considerações procuraram se ater a aspectos como rendimento térmico, relação ar/combustível, ângulo de avanço da centelha, temperatura de escape, assim como potência e eficiência volumétrica, levando em conta, sempre, a sua influência no funcionamento geral do motor. Ficou constatado que o motor movido a etanol vaporizado apresenta rendimento consideravelmente maior, menor consumo de combustível e funcionamento mais suave que aqueles verificados quando o mesmo motor e alimentado com álcool líquido.The ethanol (ethyl alcohol) has been studied more and more as alternative fuel to replace some petroleum derivatives for internal combustion engines. The attached study examines the application of vaporized ethanol for Otto cycle engines, searching for better levels of total thermal efficiency. Therefore, an engine for test of octane number (CFR motor) was equipped with an alcohol vaporizer installed inside the escape pipe, and after many experiences, several analysis were made. The various analysis included aspects as thermal efficiency, air/fuel ratio, advance ignition, escape temperature, power and volumetric efficiency, always considering their influence on the operation of the engine. It was confirmed that the engine moved by vaporized ethanol presents higher thermal efficiency, smaller fuel consumption and smoother working than in case of alimentation by liquid alcohol.
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Jeromenok, Jekaterina. "Polymers from the natural product betulin : a microstructural investigation." Phd thesis, Universität Potsdam, 2012. http://opus.kobv.de/ubp/volltexte/2012/6138/.
Повний текст джерелаАнотація:
Porous materials (e.g. zeolites, activated carbon, etc.) have found various applications in industry, such as the use as sorbents, catalyst supports and membranes for separation processes. Recently, much attention has been focused on synthesizing porous polymer materials. A vast amount of tailor-made polymeric systems with tunable properties has been investigated. Very often, however, the starting substances for these polymers are of petrochemical origin, and the processes are all in all not sustainable. Moreover, the new polymers have challenged existing characterizing methodologies. These have to be further developed to address the upcoming demands of the novel materials. Some standard techniques for the analysis of porous substances like nitrogen sorption at 77 K do not seem to be sufficient to answer all arising questions about the microstructure of such materials. In this thesis, microporous polymers from an abundant natural resource, betulin, will be presented. Betulin is a large-scale byproduct of the wood industry, and its content in birch bark can reach 30 wt.%. Based on its rigid structure, polymer networks with intrinsic microporosity could be synthesized and characterized. Apart from standard nitrogen and carbon dioxide sorption at 77 K and 273 K, respectively, gas sorption has been examined not only with various gases (hydrogen and argon) but also at various temperatures. Additional techniques such as X-ray scattering and xenon NMR have been utilized to enable insight into the microporous structure of the material. Starting from insoluble polymer networks with promising gas selectivities, soluble polyesters have been synthesized and processed to a cast film. Such materials are feasible for membrane applications in gas separation. Betulin as a starting compound for polyester synthesis has aided to prepare, and for the first time to thoroughly analyse a microporous polyester with respect to its pores and microstructure. It was established that nitrogen adsorption at 87 K can be a better method to solve the microstructure of the material. In addition to that, other betulin-based polymers such as polyurethanes and polyethylene glycol bioconjugates are presented. Altogether, it has been shown that as an abundant natural resource betulin is a suitable and cheap starting compound for some polymers with various potential applications.Das Bestreben, ölbasierte Produkte durch nachwachsende Rohstoffe zu ersetzen, hat dazu geführt, dass in immer größerer Zahl günstige, reichlich vorhandene Naturstoffe als Ausgangsstoffe für chemische Synthesen untersucht werden. In dieser Arbeit werden Polymere auf Basis von Betulin, einem aus Birkenrinde extrahierten Naturstoff, vorgestellt. Betulin ist zu 30 Gewichtsprozent in Birkenrinde enthalten. Da Betulin ein Nebenprodukt der Holzindustrie ist, ist es kostengünstig und sein Einsatz als Ausgangsstoff äußerst lukrativ. Die ersten Berichte über Betulin-basierte Polymere sind in den 1980er Jahren in Russland und Finnland erschienen, in den Ländern mit großen natürlichen Vorkommen an Birken. Betulin wurde in dieser Arbeit verwendet, um sogenannte mikroporöse Polymere herzustellen. Dies sind Stoffe mit Poren von molekularer Dimension. Mikroporöse Materialien sind wegen ihrer potentiellen Anwendung als Katalysatorträger und Gasseparationsmembranen hochinteressant. Die Klasse mikroporöser Polymere wurde durch die Synthese von unlöslichen Betulin-basierten Polyesternetzwerken erweitert. Außerdem gelang es, lösliche Polyester in Form dünner Filme herzustellen. Diese zeigten vielversprechende Ergebnisse in der Trennung von Stickstoff und Kohlendioxid und weisen somit Potential für die Nutzung als Membran auf. Dies könnte z. B. für Kohlendioxid-Reduzierung in Postcombustion-Verfahren interessant sein. Überdies wurde gezeigt, dass Stickstoffadsorption bei 77 K nicht ohne weiteres als Standardmethode für die Analyse von mikroporösen Materialien geeignet ist und dass die mikroporösen Materialien ferner durch Stickstoffadsorption bei 87 K und andere Gassorptionsmethoden bei verschiedenen Temperaturen zu charakterisieren sind. Diese Arbeit trägt zum besseren Verständnis mikroporöser Polymere bei.
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Proser, Noah. "Energy Storage: Technology for a More Efficient Grid." Scholarship @ Claremont, 2011. http://scholarship.claremont.edu/cmc_theses/264.
Повний текст джерелаАнотація:
Energy storage technologies have the potential to revolutionize the electric grid by allowing for the integration of renewable generation while increasing the utilization and efficiency of current grid assets. These technologies include pumped hydroelectric storage, compressed air energy storage (CAES), flywheels, batteries, thermal energy storage (TES), super capacitors, and superconducting magnetic energy storage (SMES). While energy storage has been implemented in some areas, its benefits are greatly undervalued by current regulatory frameworks leading to suboptimal outcomes for grid operators, utilities, and ratepayers. Large-scale adoption of storage technologies will require regulatory frameworks that recognize the benefits of grid-scale storage across generation, and transmission and distribution. This thesis discusses the need for storage, currently available and developing storage technologies, and the present regulatory environment.
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Kezibri, Nouaamane. "Etude dynamique du procédé de production de méthane à partir d’hydrogène électrolytique basse température." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLEM056/document.
Повний текст джерелаАнотація:
Ce travail s’inscrit dans le cadre de l’étude d’un système de stockage et de restitution des surplus d’énergie électrique de sources renouvelables. L’objectif de l’étude est d’évaluer la capacité du concept à absorber l’intermittence de la production électrique à travers l’analyse de la flexibilité des procédés choisis. En phase de stockage, l’unité utilise un procédé d’électrolyse basse température à membrane échangeuse de proton (PEM) pour produire l’équivalent de 200 MW d’hydrogène. Ce gaz sera combiné au dioxyde de carbone dans une série de réacteurs de méthanation pour former l’équivalent de 155 MW de substitut de gaz naturel. La phase de déstockage est réalisée au sein d’un cycle d’oxy-combustion d’une puissance installée de 480 MW. Ce cycle permet de restituer l’énergie contenue dans les gaz stockés et de produire le CO2 requis pour le procédé de méthanation. L’étude énergétique en régime stationnaire de cette installation montre que l’efficacité du procédé d’électrolyse atteint 69,3%, celle du procédé de méthanation 82,2% et celle du cycle d’oxy-combustion 51,8% sur PCS. L’analyse en régime transitoire de la phase Power-to-Gas permet d’identifier les stratégies de contrôle adaptées aux variations temporelles de conditions opératoires. Ces stratégies visent à permettre au système de couvrir des plages de fonctionnement plus larges et d’absorber plus de puissance électrique. Il s’est avéré que la production du méthane de synthèse peut s’étendre sur des plages de fonctionnement allant de 48% à 100% de la puissance nominale sans aucun apport énergétique extérieur. Le cas d’étude réalisé pour le couplage de l’unité avec un parc éolien de 300 MW permet d’évaluer les performances du Power-to-Gas en fonction de la variation de la source électriqueThe present work deals with the conceptual study and process design of a storage and recovery unit for renewable energy. The suggested concept is able to absorb the intermittency of the electrical production as a result of the flexibility of the chosen processes. During the storage phase, the unit uses a Proton Exchange Membrane electrolysis system to produce 200 MW of hydrogen, which will then be combined to carbon dioxide in a series of methanation reactors to generate up to 155 MW of Substitute Natural Gas. The recovery phase is carried out in a 480 MW oxy-combustion cycle which is not only able to restore the electrical energy but also provides the required carbon dioxide for the methanation process. The conducted steady state evaluation as well as the sensitivity analysis for the studied plant showed that the overall efficiency on HHV basis can reach up to 69.3% for the electrolysis process, 82.2% for the methanation process and 51.8% for the oxy-combustion cycle. The follow-up unsteady state analysis of the Power-to-Gas process aimed to identify the necessary control strategies adapted to operating conditions variation over time. Such strategies should enable the system to cover a wider load range and subsequently absorb more electrical power. It was found that, by making the right adjustments, the production of synthetic methane can be fulfilled at ranges between 48% and 100% of the nominal power without any external energy requirement. A case study was carried out where the unit was coupled with a 300 MW wind to assess the performance of the Power-to-Gas process under fluctuating electrical source conditions
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Arias, Quintero Sergio. "Thermal Stability Characteristics of Fisher-Tropsch and Hydroprocessed Alternative Aviation Fuels in a Fixed Bed Reactor." Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5117.
Повний текст джерелаАнотація:
Growing prices, limited supply, and public concern about greenhouse gases associated with crude-derived jet fuels have led to development of renewable alternatives which must be compatible with the worldwide civilian and military aviation infrastructure, which were designed for operation with Jet-A/JP-8. Any alternative fuel should not have negative effects on the aircraft engines and fuel systems, especially from a thermal stability perspective, since any adverse effect of the physical properties, and chemical composition, including existence of trace elements, of those fuels may only be revealed after extensive operation, resulting in higher life-cycle maintenance and operation costs. This study considered four types of alternative fuels: two derived by Fischer-Tropsch (FT) process, and two types of Hydro-processing Esters and Fatty acids (HEFA). For each of these types, both raw and 50:50 blends in volume with Jet-A samples have been prepared, thus resulting in eight different fuel blends. Fit-for-purpose ability of these alternative fuels is first investigated by studying the effects of the fuel properties and composition effects on elastomer materials, and micro-turbine performance. When elastomer o-rings, similar to those used in aircraft fuel systems were immersed in renewable fuels, smaller volume change or swelling was detected (lower than 2%), contrary to a 14% swelling observed for baseline Jet-A. Lower swelling may result into leaks during aircraft operation. This trend was reversed when renewable fuels were blended with aromatics containing Jet-A. Lower energetic content per unit volume of the renewable fuels, resulted in a thrust reduction around 10% when compared to baseline Jet-A at full throttle settings, but other than this, no other significant effect on the engine combustion temperature or other parameters were found for short duration testing. On the other hand at the end of the alternative fuel testing an injector issue was detected, which caused a localized heat zone at the turbine stator, and subsequent damage. The investigation of the causes of this nozzle fouling, which may be related to fuel contamination, turbine manufacture defects, or operation conditions is left for future studies. Primary focus of this study is coking behavior of 8 different alternative fuel blends over 4 different metallic surfaces, as compared against baseline Jet-A. A specialized single tube heat exchanger apparatus was used where each fuel sample was allowed to flow through a metal tube placed inside a tube furnace. Thermal stresses caused by the break-down of hydrocarbon molecules and the catalytic effects of the tube surfaces affect thermal stability of the fuel, leading to coking deposits under the auto-oxidation and pyrolysis mechanisms. In the results reported in this study, physical methods such as gravimetric measurements were used to obtain the deposits, while UV/VIS absorption, and GC/MS were used to study chemical changes in fuel composition and their relation with coking deposits. Thermal depositions between 16 and 46 ?g/cm2 were measured at the tubes after 3 hours of testing, finding no significant differences between the baseline Jet-A and the renewable fuels blends, even when sulfur levels, which are linked to deposits formation, were lower for the renewable fuels. Fuel bulk constituents, such as paraffins and cycloalkanes, under thermal stressing and catalytic influence of the tube metals cracked into reactive intermediates leading to surface deposits formation, like aromatic compounds. These compounds were identified by the shift towards longer excitation wavelengths of the UV-Vis absorption measurements on stressed fuels.M.S.A.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Aerospace Engineering; Thermofluid Aerodynamic Systems
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Guan, Tingting. "Biomass-fuelled PEM FuelCell systems for small andmedium-sized enterprises." Doctoral thesis, KTH, Energiprocesser, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176633.
Повний текст джерелаАнотація:
Biomass-fuelled proton exchange membrane fuel cells (PEMFCs) offer asolution for replacing fossil fuel for hydrogen production. Through using thebiomass-derived hydrogen as fuel, PEMFCs may become an efficient andsustainable energy system for small and medium-sized enterprises. The aim ofthis thesis is to evaluate the performance and potential applications of biomassfuelledPEMFC systems which are designed to convert biomass to electricity andheat. Biomass-fuelled PEMFC systems are simulated by Aspen plus based ondata collected from experiments and literature.The impact of the quality of the hydrogen-rich gas, anode stoichiometry, CH4content in the biogas and CH4 conversion rate on the performance of the PEMFCis investigated. Also, pinch technology is used to optimize the heat exchangernetwork to improve the power generation and thermal efficiency.For liquid and solid biomass, anaerobic digestion (AD) and gasification (GF),respectively, are relatively viable and developed conversion technologies. ForAD-PEMFC, a steam reformer is also needed to convert biogas to hydrogen-richgas. For 100 kWe generation, the GF-PEMFC system yields a good technicalperformance with 20 % electrical efficiency and 57 % thermal efficiency,whereas the AD-PEMFC system only has 9 % electrical efficiency and 13 %thermal efficiency. This low efficiency is due to the low efficiency of theanaerobic digester (AD) and the high internal heat consumption of the AD andthe steam reformer (SR). For the environmental aspects, the GF-PEMFC systemhas a high CO2 emissions offset factor and the AD-PEMFC system has anefficient land-use.The applications of the biomass-fuelled PEMFC systems are investigated on adairy farm and an olive oil plant. For the dairy farm, manure is used as feedstockto generate biogas through anaerobic digestion. A PEMFC qualified for 40 %electrical efficiency may generate 360 MWh electricity and 680 MWh heat peryear to make a dairy farm with 300 milked cows self-sufficient in a sustainableway. A PEMFC-CHP system designed for an olive oil plant generating annual 50000 m3 solid olive mill waste (SOMW) and 9 000 m3 olive mill waste water(OMW) is simulated based on experimental data from the Biogas2PEM-FCproject1. After the optimization of the heat exchanger network, the PEMFC-CHP system can generate 194 kW electricity which corresponds to 62 % of the totalelectricity demand of the olive oil plant.The economic performance of the PEMFC and biogas-fuelled PEMFC areassessed roughly including capital, operation & maintenance (O&M) costs of thebiogas plant and the PEMFC-CHP, the cost of heat and electricity, and the valueof the digestate as fertilizer.QC 20151109
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Alhaider, Mohemmed Masooud. "Optimal Demand Response Models with Energy Storage Systems in Smart Grids." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6451.
Повний текст джерелаАнотація:
This research aims to develop solutions to relieve system stress conditions in electric grids. The approach adopted in this research is based on a new concept in the Smart Grid, namely, demand response optimization. A number of demand response programs with energy storage systems are designed to enable a community to achieve optimal demand side energy management.
The proposed models aim to improve the utilization of the demand side energy through load management programs including peak shaving, load shifting, and valley lling. First, a model is proposed to nd the optimal capacity of the battery energy storage system (BESS) to be installed in a power system. This model also aims to design optimal switchable loads programs for a community. The penetration of the switchable loads versus the size of the BESS is investigated. Another model is developed to design an optimal load operation scheduling of a residential heating ventilation and air-conditioning system (HVACs). This model investigates the ability of HVACs to provide optimal demand response. The model also proposes a comfort/cost trade-os formulation for end users. A third model is proposed to incorporate the uncertainty of the photovoltaic power in a residential model. The model would nd the optimal utilization of the PV-output to supply the residential loads.
In the first part of this research, mixed integer programming (MIP) formulations are proposed to obtain the optimal capacity of the (BESS) in a power system. Two optimization problems are investigated: (i) When the BESS is owned by a utility, the operation cost of generators and cost of battery will be minimized. Generator on/o states, dispatch level and battery power dispatch level will be determined for a 24-hour period. (ii) When the BESS is owned by a community for peak shaving, the objective function will have a penalty component for the deviation of the importing power from the scheduled power. MIP problems are formulated and solved by CPLEX.The simulation results present the effect of switchable load penetration level on battery sizing parameters.
In the second part, a mixed integer programming (MIP) based operation is proposed in this part for residential HVACs. The objective is to minimize the total cost of the HVAC energy consumption under varying electricity prices. A simplied model of a space cooling system considering thermal dynamics is adopted. The optimization problems consider 24-hour operation of HVAC. Comfort/cost trade-o is modeled by introducing a binary variable. The big-M technique is adopted to obtain linear constraints while considering this binary variable. The MIP problems are solved by CPLEX. Simulation results demonstrate the effectiveness of HVAC's ability to respond to varying electricity price.
Then, in the final part of this research, two Benders Decomposition strategies are applied to solve a stochastic mixed integer programming (MIP) formulation to obtain the optimal sizing of a photovoltaic system (PV) and battery energy storage system (BESS) to power a residential HVACs. The uncertainty of PV output is modeled using stochastic scenarios with the probability of their occurrence. Total cost including HVAC energy consumption cost and PV/battery installation cost is to be minimized with the system at grid-connected mode over eight hours subject to a varying electricity price. The optimization problem will nd the optimal battery energy capacity, power limit, a number of PV to be installed, and expected HVAC on/o states and BESS charging/discharging states for the next eight hours. This optimization problem is a large-scale MIP problem with expensive computing cost.