994 resultados para GAS NATURAL - ASPECTOS POLITICOS - RUSIA


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Finland, other Nordic countries and European Union aim to decarbonize their energy production by 2050. Decarbonization requires large scale implementation of non-emission energy sources, i.e. renewable energy and nuclear power. Stochastic renewable energy sources present a challenge to balance the supply and demand for energy. Energy storages, non-emissions fuels in mobility and industrial processes are required whenever electrification is not possible. Neo-Carbon project studies the decarbonizing the energy production and the role of synthetic gas in it. This thesis studies the industrial processes in steel production, oil refining, cement manufacturing and glass manufacturing, where natural gas is already used or fuel switch to SNG is possible. The technical potential for fuel switching is assessed, and economic potential is necessary after this. All studied processes have potential for fuel switching, but total decarbonization of steel production, oil refining requires implementation of other zero-emission technologies.

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The global interest towards renewable energy production such as wind and solar energy is increasing, which in turn calls for new energy storage concepts due to the larger share of intermittent energy production. Power-to-gas solutions can be utilized to convert surplus electricity to chemical energy which can be stored for extended periods of time. The energy storage concept explored in this thesis is an integrated energy storage tank connected to an oxy-fuel combustion plant. Using this approach, flue gases from the plant could be fed directly into the storage tank and later converted into synthetic natural gas by utilizing electrolysis-methanation route. This work utilizes computational fluid dynamics to model the desublimation of carbon dioxide inside a storage tank containing cryogenic liquid, such as liquefied natural gas. Numerical modelling enables the evaluation of the transient flow patterns caused by the desublimation, as well as general fluid behaviour inside the tank. Based on simulations the stability of the cryogenic storage and the magnitude of the key parameters can be evaluated.

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This thesis studies energy efficiencies and technical properties of gas driven ground source heat pumps and pump systems. The research focuses on two technologies: gas engine driven compressor heat pump and thermally driven gas absorption heat pump. System consist of a gas driven compressor or absorption ground source heat pump and a gas condensing boiler, which covers peak load. The reference system is a standard electrically powered compressor heat pump with electric heating elements for peak load. The systems are compared through primary energy ratios. Coefficient of performances of different heat pump technologies are also compared. At heat pump level, gas driven heat pumps are having lower coefficient of performances as compared with corresponding electric driven heat pump. However, gas heat pumps are competitive when primary energy ratios, where electricity production losses are counted in, are compared. Technically, gas heat pumps can potentially achieve a slightly higher temperatures with greater total energy efficiency as compared to the electric driven heat pump. The primary energy ratios of gas heat pump systems in relation to EHP-system improves when the share of peak load increases. Electric heat pump system's overall energy efficiency is heavily dependent on the electricity production efficiency. Economy as well as CO2-emissions were not examined in this thesis, which however, would be good topics for further study.

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Solar and wind power produce electricity irregularly. This irregular power production is problematic and therefore production can exceed the need. Thus sufficient energy storage solutions are needed. Currently there are some storages, such as flywheel, but they are quite short-term. Power-to-Gas (P2G) offers a solution to store energy as a synthetic natural gas. It also improves nation’s energy self-sufficiency. Power-to-Gas can be integrated to an industrial or a municipal facility to reduce production costs. In this master’s thesis the integration of Power-to-Gas technologies to wastewater treatment as a part of the VTT’s Neo-Carbon Energy project is studied. Power-to-Gas produces synthetic methane (SNG) from water and carbon dioxide with electricity. This SNG can be considered as stored energy. Basic wastewater treatment technologies and the production of biogas in the treatment plant are studied. The utilisation of biogas and SNG in heat and power production and in transportation is also studied. The integration of the P2G to wastewater treatment plant (WWTP) is examined mainly from economic view. First the mass flows of flowing materials are calculated and after that the economic impact based on the mass flows. The economic efficiency is evaluated with Net Present Value method. In this thesis it is also studied the overall profitability of the integration and the key economic factors.

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O conhecimento dos caracteres morfológicos de plântulas e mudas é de grande importância em trabalhos de laboratório, viveiros de produção de mudas e estudos de avaliação da regeneração natural, facilitando assim, o reconhecimento e a identificação das espécies. Neste sentido, os objetivos deste trabalho foram descrever e ilustrar os aspectos morfológicos externos do desenvolvimento de plântulas e mudas de trema (Trema micrantha (L.) Blum.) - ULMACEAE, para fins de identificação taxonômica. O reconhecimento taxonômico da espécie é possível por meio dos caracteres morfológicos externos, seja a partir da plântula ou da muda. Aspectos como a germinação fanerocotiledonar e a modificação da filotaxia, passando de protófilos opostos para metáfilos alternos são importantes para a identificação da espécie.

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O presente trabalho foi realizado com o objetivo de caracterizar morfologicamente frutos, sementes, plântulas e mudas de duas espécies arbóreas da família Leguminosae Mimosoideae, de ocorrência natural no estado de Sergipe para fins taxonômicos, estudos de regeneração natural e recuperação de matas ciliares. Descreveu-se e se ilustrou as características morfológicas de angico [Anadenanthera colubrina (Vellozo) Brenan] e tamboril [Enterolobium contortisiliquum (Vellozo) Morong]. Os frutos foram coletados com auxílio de podão, em cinco árvores-matrizes, distantes no mínimo 50 m entre si. Foram realizadas avaliações das características morfométricas e morfológicas externas e internas dos frutos e sementes e externas de plântulas e mudas. A. colubrina apresenta fruto seco e deiscente, enquanto em E. contortisiliquum os frutos são secos e indeiscentes. Ambas as espécies apresentam pleurograma e são exalbuminosas. Os caracteres do embrião e a germinação epígea-fanerocotiledonar são semelhantes àqueles observados em Caesalpinioideae. Na fase de muda, a presença de nectários glandulares extraflorais situados na ráquis em A. colubrina e lenticelas em E. contortisiliquum são úteis para as respectivas identificações. A presença de raiz com nódulos em E. contortisiliquum e tuberosa em A. colubrina são fundamentais para a precisa identificação destas. Com os resultados obtidos, conclui-se que a morfologia interna e externa dos frutos e das sementes e a morfologia externa das plântulas e mudas permitem fazer a identificação imediata e segura, fornecendo subsídios para estudos com as espécies estudadas, seja em laboratório ou em viveiro de produção de mudas e no campo das espécies estudadas.

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Pretende-se explorar alguns aspectos da obra de Franz Kafka que vinculam as experiências do escritor às experiências do homem das grandes cidades modernas, e, por outro lado, colocam essas mesmas experiências "sob violenta tensão em relação às místicas". Alguns elementos da obra de Kafka, como a impessoalidade, o anonimato, os inúmeros corredores ou repartições sufocantes, representam um diagnóstico, tido muitas vezes como sombrio, mas essencialmente crítico da modernidade. A partir da parábola Diante da Lei , inserida no romance O Processo e contada ao protagonista como uma forma de ligar sua experiência à tradição, procurar-se-á discutir tanto o papel da crítica à modernidade como o papel desempenhado pela tradição ( a teologia judaica), além das noções de culpa e lei, natural e sobrenatural.

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Las investigaciones sobre Luis de León se han centrado, sobre todo, en su mística, narrativa y teoría literaria. En este trabajo, el autor intenta desarrollar los principales aspectos de su teoría jurídica. Al igual que otros grandes teólogos de la Escuela de Salamanca, también León ha estudiado el problema de la naturaleza de la ley humana y su vinculación con el derecho natural. Éste es, justamente, el tema del siguiente trabajo.

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Au cours des dernières décennies, l’intérêt pour la gazéification de biomasses a considérablement augmenté, notamment en raison de la grande efficacité de recouvrement énergétique de ce procédé par rapport aux autres procédés de génération de bioénergies. Les composants majoritaires du gaz de synthèse, le monoxyde de carbone (CO) et l’hydrogène (H2) peuvent entre autres servir de substrats à divers microorganismes qui peuvent produire une variété de molécules chimiques d’intérêts, ou encore produire des biocarburants, particulièrement le méthane. Il est donc important d'étudier les consortiums méthanogènes naturels qui, en syntrophie, serait en mesure de convertir le gaz de synthèse en carburants utiles. Cette étude évalue principalement le potentiel de méthanisation du CO par un consortium microbien issu d’un réacteur de type UASB, ainsi que les voies métaboliques impliquées dans cette conversion en conditions mésophiles. Des tests d’activité ont donc été réalisés avec la boue anaérobie du réacteur sous différentes pressions partielles de CO variant de 0.1 à 1,65 atm (0.09 à 1.31 mmol CO/L), en présence ou absence de certains inhibiteurs métaboliques spécifiques. Dès le départ, la boue non acclimatée au CO présente une activité carboxidotrophique relativement intéressante et permet une croissance sur le CO. Les tests effectués avec de l’acide 2- bromoethanesulfonique (BES) ou avec de la vancomycine démontrent que le CO est majoritairement consommé par les bactéries acétogènes avant d’être converti en méthane par les méthanogènes acétotrophes. De plus, un plus grand potentiel de méthanisation a pu être atteint sous une atmosphère constituée uniquement de CO en acclimatant auparavant la boue. Cette adaptation est caractérisée par un changement dans la population microbienne désormais dominée par les méthanogènes hydrogénotrophes. Ceci suggère un potentiel de production à large échelle de biométhane à partir du gaz de synthèse avec l’aide de biofilms anaérobies.

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The research work which was carried out to characterization of wastes from natural rubber and rubber wood processing industries and their utilization for biomethanation. Environmental contamination is an inevitable consequence of human activity. The liquid and solid wastes from natural rubber based industries were: characterized and their use for the production of biogas investigated with a view to conserve conventional energy, and to mitigate environmental degradation.Rubber tree (flevea brasiliensis Muell. Arg.), is the most important commercial source of natural rubber and in india. Recently, pollution from the rubber processing factories has become very serious due to the introduction of modern methods and centralized group processing practices.The possibility of the use of spent slurry as organic manure is discussed.l0 percent level of PSD, the activity of cellulolytic, acid producing,proteolytic, lipolytic and methanogenic bacteria were more in the middle stage of methanogenesis.the liquid wastes from rubber processing used as diluents in combination with PSD, SPE promoted more biogas production with high methane content in the gas.The factors that favour methane production like TS, VS, cellulose and hemicellulose degradation were favoured in this treatment which led to higher methane biogenesis.The results further highlight ways and means to use agricultural wastes as alternative sources of energy.

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Energy production from biomass and the conservation of ecologically valuable grassland habitats are two important issues of agriculture today. The combination of a bioenergy production, which minimises environmental impacts and competition with food production for land with a conversion of semi-natural grasslands through new utilization alternatives for the biomass, led to the development of the IFBB process. Its basic principle is the separation of biomass into a liquid fraction (press fluid, PF) for the production of electric and thermal energy after anaerobic digestion to biogas and a solid fraction (press cake, PC) for the production of thermal energy through combustion. This study was undertaken to explore mass and energy flows as well as quality aspects of energy carriers within the IFBB process and determine their dependency on biomass-related and technical parameters. Two experiments were conducted, in which biomass from semi-natural grassland was conserved as silage and subjected to a hydrothermal conditioning and a subsequent mechanical dehydration with a screw press. Methane yield of the PF and the untreated silage was determined in anaerobic digestion experiments in batch fermenters at 37°C with a fermentation time of 13-15 and 27-35 days for the PF and the silage, respectively. Concentrations of dry matter (DM), ash, crude protein (CP), crude fibre (CF), ether extract (EE), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent ligning (ADL) and elements (K, Mg, Ca, Cl, N, S, P, C, H, N) were determined in the untreated biomass and the PC. Higher heating value (HHV) and ash softening temperature (AST) were calculated based on elemental concentration. Chemical composition of the PF and mass flows of all plant compounds into the PF were calculated. In the first experiment, biomass from five different semi-natural grassland swards (Arrhenaterion I and II, Caricion fuscae, Filipendulion ulmariae, Polygono-Trisetion) was harvested at one late sampling (19 July or 31 August) and ensiled. Each silage was subjected to three different temperature treatments (5°C, 60°C, 80°C) during hydrothermal conditioning. Based on observed methane yields and HHV as energy output parameters as well as literature-based and observed energy input parameters, energy and green house gas (GHG) balances were calculated for IFBB and two reference conversion processes, whole-crop digestion of untreated silage (WCD) and combustion of hay (CH). In the second experiment, biomass from one single semi-natural grassland sward (Arrhenaterion) was harvested at eight consecutive dates (27/04, 02/05, 09/05, 16/05, 24/05, 31/05, 11/06, 21/06) and ensiled. Each silage was subjected to six different treatments (no hydrothermal conditioning and hydrothermal conditioning at 10°C, 30°C, 50°C, 70°C, 90°C). Energy balance was calculated for IFBB and WCD. Multiple regression models were developed to predict mass flows, concentrations of elements in the PC, concentration of organic compounds in the PF and energy conversion efficiency of the IFBB process from temperature of hydrothermal conditioning as well as NDF and DM concentration in the silage. Results showed a relative reduction of ash and all elements detrimental for combustion in the PC compared to the untreated biomass of 20-90%. Reduction was highest for K and Cl and lowest for N. HHV of PC and untreated biomass were in a comparable range (17.8-19.5 MJ kg-1 DM), but AST of PC was higher (1156-1254°C). Methane yields of PF were higher compared to those of WCD when the biomass was harvested late (end of May and later) and in a comparable range when the biomass was harvested early and ranged from 332 to 458 LN kg-1 VS. Regarding energy and GHG balances, IFBB, with a net energy yield of 11.9-14.1 MWh ha-1, a conversion efficiency of 0.43-0.51, and GHG mitigation of 3.6-4.4 t CO2eq ha-1, performed better than WCD, but worse than CH. WCD produces thermal and electric energy with low efficiency, CH produces only thermal energy with a low quality solid fuel with high efficiency, IFBB produces thermal and electric energy with a solid fuel of high quality with medium efficiency. Regression models were able to predict target parameters with high accuracy (R2=0.70-0.99). The influence of increasing temperature of hydrothermal conditioning was an increase of mass flows, a decrease of element concentrations in the PC and a differing effect on energy conversion efficiency. The influence of increasing NDF concentration of the silage was a differing effect on mass flows, a decrease of element concentrations in the PC and an increase of energy conversion efficiency. The influence of increasing DM concentration of the silage was a decrease of mass flows, an increase of element concentrations in the PC and an increase of energy conversion efficiency. Based on the models an optimised IFBB process would be obtained with a medium temperature of hydrothermal conditioning (50°C), high NDF concentrations in the silage and medium DM concentrations of the silage.

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Documento que recoge una propuesta de contenidos específicos de Diseño Curricular Base, dirigidos a población adulta referidas a la región de Murcia dentro del área de Conocimiento de Medio natural, social y cultural para la formación básica, así como en el área de las Ciencias Sociales para la ESO en el marco del Real Decreto 6 de septiembre de 1991. La idea fundamental es ser un documento de debate y experimentación entre todas las personas implicadas en la educación de adultos, dirigido a conseguir un Diseño Curricular válido, que cualifique este área educativa y optimice los recursos empleados.

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Material multicopiado. Incluye una versión en inglés

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The identification of compositional changes in fumarolic gases of active and quiescent volcanoes is one of the most important targets in monitoring programs. From a general point of view, many systematic (often cyclic) and random processes control the chemistry of gas discharges, making difficult to produce a convincing mathematical-statistical modelling. Changes in the chemical composition of volcanic gases sampled at Vulcano Island (Aeolian Arc, Sicily, Italy) from eight different fumaroles located in the northern sector of the summit crater (La Fossa) have been analysed by considering their dependence from time in the period 2000-2007. Each intermediate chemical composition has been considered as potentially derived from the contribution of the two temporal extremes represented by the 2000 and 2007 samples, respectively, by using inverse modelling methodologies for compositional data. Data pertaining to fumaroles F5 and F27, located on the rim and in the inner part of La Fossa crater, respectively, have been used to achieve the proposed aim. The statistical approach has allowed us to highlight the presence of random and not random fluctuations, features useful to understand how the volcanic system works, opening new perspectives in sampling strategies and in the evaluation of the natural risk related to a quiescent volcano

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Los dibujos son de L. Frechilla