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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
721

Conflitos e contratos: a Petrobras, o nacionalismo boliviano e a interdepedência do gás natural (2002-2010) / Conflicts and contracts: Petrobras, Bolivian nationalism and interdependence of natural gas (2002-2010)

Igor Fuser 20 September 2011 (has links)
A nacionalização dos hidrocarbonetos pelo presidente boliviano Evo Morales, em maio de 2006, provocou a mais séria crise na política externa brasileira durante o primeiro mandato presidencial de Lula. A decisão prejudicou os interesses da Petrobras, na época a maior empresa instalada na Bolívia, com presença em todos os ramos da atividade petroleira. O conflito foi amplificado pela existência de uma relação de interdependência entre os dois países com base no gasoduto de 3.150 quilômetros, que transporta quase a metade do gás natural consumido pela indústria no Brasil. Com a nacionalização sem expropriação, segundo a fórmula adotada por Morales, as empresas estrangeiras foram autorizadas a permanecer na Bolívia, mas tiveram de renegociar seus contratos, aceitando a ampliação da receita fiscal (government take) obtida pelo governo a partir da produção petroleira. Essa decisão do governo boliviano expôs as contradições da política do Brasil para a América do Sul. Lula, pressionado pela oposição conservadora, intercedeu em defesa dos lucros da Petrobras, mas ao mesmo tempo reconheceu a nacionalização como expressão do direito soberano da Bolívia em legislar sobre seus próprios recursos naturais, abstendo-se de represálias. A tese explora a ambigüidade do comportamento regional do Brasil, que tenta conciliar um discurso de solidariedade em relação aos vizinhos menos desenvolvidos com uma política de expansão das empresas brasileiras e de proteção dos investimentos no exterior. O conflito em torno do gás boliviano abalou os planos brasileiros de liderança regional sul-americana e tornou mais difícil a integração energética, uma das prioridades da política externa de Lula. / The nationalization of hidrocarbons by Bolivian president Evo Morales, in May 2006, has provocated the most serious crisis in Brazilian foreign policy during Lulas first presidential term. The decision has damaged the interests of Petrobras, then the biggest corporation in Bolivia, operating in all branches of oil activities. The conflict was amplified by the interdependent relationship between the two countries through a 3.150 kilometers gasoduct, which carries almost half the natural gas consumed by Brazilian industry. By nationalization without expropriation, according to Morales formula, foreign oil corporations were allowed to stay in Bolivia, but were forced to renegociate their contracts, increasing the government take on oil and gas production. Bolivian governments decision has exposed the contradictions of Brazilian foreign policy towards its South American neighbors. Lula, under pressure from conservative opposition, has acted on behalf of Petrobras profits, but at the same time he recognized Bolivian right to set the rules on its own natural resources, and has not taken any reprisal. The thesis explores the ambiguities of Brazilian regional behavior, trying to conciliate a discourse of solidarity to lesser developed neighbors with the international expansion of Brazilian companies and investment protection abroad. The conflict about Bolivian gas has shattered Brazilian plans for regional leadership and turned more difficult energy regional integration, one of the priorities of Lulas foreign policy.
722

Substituição do gás de coqueria por gás natural no sistema de Ignição de uma caldeira de produção de vapor /

Lago, Diogo Theodoro January 2020 (has links)
Orientador: João Andrade de Carvalho / Resumo: Caldeiras de produção de vapor são utilizadas no setor siderúrgico para produzir e disponibilizar vapor para o processo de geração de energia e para os vários setores que necessitam de aquecimento durante a fabricação de seus produtos, como por exemplo, a vaporização de criogênicos para distribuição na planta. Portanto, caldeiras são equipamentos que necessitam ter confiabilidade. Atualmente, a CSN (siderúrgica brasileira de grande porte) possui duas caldeiras do início da década de 80 que somente partem e operam com uma chama piloto utilizando gás de coqueria, um gás que é subproduto da produção de coque em uma planta siderúrgica. Assim, para alcançar o objetivo de mais confiabilidade e flexibilidade na operação destas caldeiras, utilizou-se os métodos de índice Wobbe, corrigido pela pressão, e o método dos múltiplos índices de Weaver para avaliar a substituição do gás de coqueria pelo gás natural de modo que estas caldeiras possam operar com gás natural em caso de indisponibilidade de gás de coqueria. Mesmo que o aporte energético entre os gases seja diferente, este pode ser ajustado pela pressão do gás. A temperatura de chama adiabática não tem variação significativa, reduzindo-se apenas 1,4%. As emissões de fumaças e CO2 aumentam com a substituição, porém as emissões de NOx tem redução. A utilização do método dos múltiplos índices de Weaver para análise de intercambiabilidade demonstra que o gás natural não é um substituo para um queimador projetado para queimar gás de co... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Steam generators are used in the steel industry to produce and supply steam process for power generation and for other sectors that need heat to manufacture their products, such as the cryogenics vaporization for distribution in the facilities. Therefore, steam generators are equipment that need to have reliability. Currently, CSN (large Brazilian steelmaker) has two steam generators from the early 1980s that only startup and operate with a pilot flame using coke oven gas, a gas that is a byproduct of coke production at a steel plant. Thus, in order to achieve the working objective, reliability and flexibility in the operation of these steam generators, the Wobbe index method, with pressure-corrected, and the Weaver's multiple index method were used to verify the coke oven replacement for natural gas, and then, these steam generators can operate with natural gas in case of coke oven gas unavailability. Results shown in the same way that the energy increase between the gases are different can be adjusted in the pressure reduction. The flame temperature has insignificant variation, only 1.4%. Off gas and CO2 emissions increase with interchangeability. However, NOx emissions are reduced. The Weaver multiple index method for interchangeability analysis demonstrates that natural gas is not a gas to replace coke oven gas in a burner designed to burn coke oven gas, but if the burner is designed to natural gas, coke oven gas may be the substitute gas. Regarding the heat input and pri... (Complete abstract click electronic access below) / Mestre
723

The Russian Federation - the European economy’s future powerhouse? : An Econometric Analysis of the Energy Import Relationship Between Seven European Key Countries and the Russian Federation / Europas Framtida Energileverantör : En ekonometrisk analys av energiimport förhållandet mellan sju europeiska nyckelländer och Ryssland.

Olofsson, Linus, Savelainen, Mikael January 2017 (has links)
The purpose of this thesis is to analyze how the world market price of crude oil, coal and natural gas affects the demand of and dependency on energy imports from the Russian Federation of key European countries[1]. We achieve our objective through econometric estimations of import demand equations concerning imports from the Russian Federation of crude oil, coal and natural gas for seven EU key countries during 1990-2014.Three out of twenty-one models were found to be statistically significant for both the spot price- and income elasticity. The spot price elasticities for the models where: coal import demand for Finland (-0.49), crude oil import demand for Italy (-0.44) and the Netherlands (-0.42). The income elasticities for the aforementioned models were found to be: Finland (2.58), Italy (5.85) and the Netherlands (7.62). The remaining models were statistically insignificant presumably due to different internal structures in the data or due to the assumption of perfect substitute model. [1] EU key countries include: Austria, Finland, France, Germany, Italy, Netherlands, and the United Kingdom. / Syftet med denna uppsats är att analysera hur världsmarknadspriset på råolja, kol och naturgas påverkar den europeiska efterfrågan på och beroendet av energiimport från Ryssland. Ekonometriska uppskattningar av importefterfrågan för råolja, kol och naturgas som produceras av Ryska Federationen för sju EU nyckelländer kommer att produceras. Huvudsyftet är att uppskatta elasticiteter hos importefterfrågan som kännetecknar de handelsförbindelserna mellan Ryssland och sju EU nyckelländerna med avseende på de tre energiresurser.  Tre av tjugoen modeller visade sig vara signifikanta för både världsmarknadspriset och inkomstelasticiteten. Följande variabler och elasticiteter för priset var signifikant; Kol Importefterfrågan för Finland (-0,49), Olje Importefterfrågan för Italien (-0,44) och Nederländerna (-0,42). Inkomstelasticitet för de nämnda modellerna estimeras vara; Finland (2,58), Italien (5,85) och Nederländerna (7,62). Den statistiska insignifikansen hos de övriga modellerna härstamma troligtvis från den interna strukturen på datat eller antagandet om den perfekta substitut modellen
724

NUMERICAL INVESTIGATION OF NON-TRADITIONAL GASEOUS FUEL INJECTION INTO THE IRONMAKING BLAST FURNACE

Samuel Nielson (11217825) 04 August 2021 (has links)
As the largest source of iron in North America, and as the largest energy consumer in the modern integrated steel mill, the blast furnace is a critical part of modern ironmaking. Any improvements that can be made to the efficiency or emissions of the blast furnace can have far reaching environmental impacts as the production of one ton of steel results in 1.85 tons of carbon dioxide emissions. Given the concerted push to reduce greenhouse emissions, novel technologies are needed to improve efficiency. In this study the injection of preheated natural gas, precombusted syngas from a variety of feedstocks, and hydrogen injection were all modeled using computational fluid dynamics, from the tuyere through the shaft of the furnace. The impacts of these various operational changes were evaluated using CFD calculated analogs for Raceway adiabatic flame temperature (RAFT), top gas temperature (TGT), and coke rate (CR). Results indicate that a reduction of 3% to 12% in CO2 emissions is possible through the implementation of these technologies, with each possessing distinct benefits and drawbacks for industrial implementation.
725

Návrh parního plynového kotle / Design of steam gas boiler

Kuriál, Jakub January 2020 (has links)
This thesis deals with a design of a steam boiler combusting natural gas. It consists of stoichiometric calculation, determination of boiler efficiency, thermal calculations and determining geometric parameters of the boiler and its heat transfer surfaces. The results are verified by the heat balance of the boiler.
726

Využití bioplynu v plynárenské síti / Utilization of biogas in gas distribution system

Frühbauer, Zdeněk January 2012 (has links)
The thesis deals with the technologies upgrading the biogas to the quality of the natural gas for the following use in the gas distribution system. The main concern of the thesis is the pressure swing adsorption (PSA), which is nowadays one of the most exploited technologies. For a certain flow and composition of the biogas, completely new PSA technology was designed. Technological schema was created and the main technological devices (adsorbers) were drawn up together with the design documentation for this new technology. The important part of the thesis is also the model of the whole PSA technology in the ChemCAD programme and the evaluation of the operating and investment costs.
727

Tepelný výpočet parního kotle / Thermal calculation of steam boiler

Růžička, Tomáš January 2012 (has links)
The topic of this thesis is the thermal calculation of steam boiler with natural gas fuel. The first part is describing technical characteristic and parametres of the boiler. The main part of this thesis is the thermal calculation of the boiler. The following part deals with determination of steam amount and steam parametres for blowing through pipes of the boiler.
728

Návrh kotle na spoluspalování zemního plynu a vysokopecního plynu / Draft boilers for co-firing natural gas and blast furnace gas

Šebela, Jakub January 2016 (has links)
The aim of a diploma thesis is design of draft boiler for co-firing blast furnace gas and natural gas. In the first part is made the stoichiometric calculation for the gas mixture. Next is the proposal of combustion chamber and proposal of individual heating surfaces of boiler. Next part contains the thermal calculation and control of individual heating surfaces. Part of the work is also drawing documentation of boiler.
729

Charakteristické vlastnosti spalování nízko-výhřevných paliv / Characteristic parameters of combustion of low calorific fuels

Kvapil, Matěj January 2017 (has links)
The diploma thesis is focused on the combustion of the low calorific gaseous fuels. The first part is devoted to the characterization and usage of low calorific fuels. Then combustion theory focused mainly on emissions and thermodynamics. Next characterization of burners and their modifications for low calorific value fuels is described. Safe storage and handling of chosen gases is also included in the last chapter of the theoretical part. Practical part includes the description of the laboratory experiment, which was a part of this thesis. It consists of the experiment description, experimental plan, calculation and evaluation of emissions, high and low heating value, density, flame temperatures and heat flux. Laboratory experiment was carried out with different fuels. Low calorific fuels were simulated by gradual increase of the concentration of inert gasses in the natural gas. Increased concentration of inert gasses had positive effect on the emissions. Measurement of the flame temperatures confirmed that the decrease of emissions corresponds to the inert gas addition to the noble fuel. Heat flux and thermal efficiency of the combustion was almost identical for each configuration.
730

Engineering and Financial Analysis of a Wastewater Pant Upgrade

Meher Rusi Taleyarkhan (8790857) 01 May 2020 (has links)
<p>Municipal wastewater treatment plants treat wastewater such as domestic and industrial sewage and recirculates the clean water back into nature’s waterways. However, the wastewater treatment process is costly and complex. The cost of running a municipal wastewater treatment plant is funded via ratepayer fee dollars from customers and therefore receives a fixed budget for which to run the plant according to environmental standards. A local initiative was established to upgrade a Midwestern municipal wastewater facility to utilize biomass renewable energy to a greater extent than what is used by the wastewater facility. The first phase of the initiative tested the suitability of utilizing organic substrates from local industrial plants with the potential to produce larger amounts of biogas via anaerobic digestion. The analysis evaluated the technical and financial viability of utilizing biomass technologies to help power the facility efficiently and economically. The financial and technical analysis will include a cost-benefit analysis by comparing current and forecasted natural gas demand and costs for running heating the WWTP to biogas produced by the anerobic digesters. The results of the research study found that the industrial waste substrates are suitable for anaerobic digestion and yield a higher biogas potential than what is currently used for anaerobic digestion by the WWTP. The initial financial analysis found it is feasible and economical, for at least certain months of the year, for the WWTP to refrain from purchasing natural gas and instead utilize the produced biogas.</p>

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