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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.
11

Energy-saving biomass stove: Short communication

Hoang, Tri 09 December 2015 (has links)
This paper introduces an energy-saving biomass stove. The principle of energy-saving biomass stove is gasification. It is a chemical process, transforms solid fuel into a gas mixture, called (CO + H2 + CH4) gas. Emission lines in the stove chimneys typically remain high temperatures around 900 to 1200C. The composition of the flue gas consists of combustion products of rice husk which are mainly CO2, CO, N2. A little volatile in the rice husk, which could not burn completely, residual oxygen and dust will fly in airflow. The amount of dust in the outlet gas is a combination of unburnt amount of impurity and firewood, usually occupied impurity rate of 1 % by weight of dry husk. Outlet dust of rice husk furnace has a normal size from 500μm to 0.1 micron and a particle concentration ranges from 200-500 mg/m3. Gas emissions is created when using energy-saving stove and they will be used as the main raw material in combustion process Therefore the CO2 emission into the environment when using the stove will be reduced up to 95% of a commonly used stove. / Bài báo giới thiệu một bếp tiết kiệm dùng năng lượng sinh khối. Bếp tiết kiệm năng lượng thực hiện nguyên lý khí hóa sinh khối. Đó là một quá trình hóa học, chuyển hóa các loại nhiên liệu dạng rắn thành một dạng hỗn hợp khí đốt, gọi là khí Gas (CO + H2 + CH4). Dòng khí thải ra ở ống khói của bếp thông thường có nhiệt độ vẫn còn cao khoảng 900 ~ 1200C. Thành phần của khói thải bao gồm các sản phẩm cháy của trấu, chủ yếu là các khí CO2, CO, N2, một ít các chất bốc trong trấu không kịp cháy hết, oxy dư và tro bụi bay theo dòng khí. Lượng bụi tro có trong khói thải chính là một phần của lượng không cháy hết và lượng tạp chất không cháy có trong củi, lượng tạp chất này thường chiếm tỷ lệ 1% trọng lượng trấu khô.Bụi trong khói thải lò đốt trấu thông thường có kích thước hạt từ 500μm tới 0,1μm, nồng độ dao động trong khoảng từ 200-500 mg/m3. Lượng khí thải được sinh ra khi sử dụng bếp tiết kiệm năng lượng, sẽ được dùng làm nguyên liệu đốt cháy chính của quá trình đó. Do đó lượng khí CO2 thải ra môi trường khi sử dụng bếp tiết kiệm sẽ được giảm xuống 95 % so với sử dụng bếp thường.
12

Avaliação das conseqüências da produção de concreto no Brasil para as mudanças climáticas. / Assessment of the consequences of the concrete production in Brazil for the climate change.

Lima, José Antonio Ribeiro de 20 January 2010 (has links)
O segmento de concreto brasileiro contribui para as mudanças climáticas devido às emissões de CO2 e as possibilidades de reduções de emissões com maior visibilidade, atualmente, são as referentes ao setor cimenteiro. Mas, o cimento tem seu consumo aumentado devido às condições de aplicação no concreto, o que torna importante a análise das emissões nesta aplicação e das possibilidades de redução. Estes foram os objetivos desta pesquisa. A emissão estimada no concreto nacional foi de 224 kgCO2/m³. Para o cimento, foi de 659 kgCO2/t, que é inferior à emissão mundial, e que pode ser reduzida pela troca de combustíveis usados no setor. O patamar atual de mitigação na produção do cimenteiro nacional situa-se em torno de 20%, podendo chegar a aproximadamente 30% com medidas como uso exclusivo de biomassa como fonte de energia, ainda não possível no setor. As reduções no concreto podem chegar a 30%, pelo aumento no rigor na preparação deste material e pela redução de desperdício. Demonstrou-se, nesta pesquisa, que es se patamar de redução é tão significativo quanto o do setor cimenteiro. / The Brazilian concrete sector contributes to the climate change due to its CO2 emissions, that can be reduced through efforts of the cement sector, that have been receiving great attention. But the use of the cement in concrete can increase its consumption if made in the wrong way, and this can increase the CO2 emissions, making important the study of the emissions in concrete and the study of the possibilities of mitigation. These were the main aims of this thesis, that demonstrated that the CO2 reduction potential in the concrete have the same magnitude of the potential in the cement. The emission in the concrete, in Brazil, is 224 kgCO2/t. In cement, is 659 kgCO2/t, that is lower than the global emission and can be reduced by changes in the fuels used in the cement production. The Brazilian cement sector can reduce its emission in 20% and, using only biomass as fuel, this reduction can reach 30%, but this is not possible, yet. Emission reduction in the concrete production and use may reach 30%, through better preparation of concretes and reducing waste of material in constructions. This value is similar to the emission mitigation in the cement sector.
13

Avaliação das conseqüências da produção de concreto no Brasil para as mudanças climáticas. / Assessment of the consequences of the concrete production in Brazil for the climate change.

José Antonio Ribeiro de Lima 20 January 2010 (has links)
O segmento de concreto brasileiro contribui para as mudanças climáticas devido às emissões de CO2 e as possibilidades de reduções de emissões com maior visibilidade, atualmente, são as referentes ao setor cimenteiro. Mas, o cimento tem seu consumo aumentado devido às condições de aplicação no concreto, o que torna importante a análise das emissões nesta aplicação e das possibilidades de redução. Estes foram os objetivos desta pesquisa. A emissão estimada no concreto nacional foi de 224 kgCO2/m³. Para o cimento, foi de 659 kgCO2/t, que é inferior à emissão mundial, e que pode ser reduzida pela troca de combustíveis usados no setor. O patamar atual de mitigação na produção do cimenteiro nacional situa-se em torno de 20%, podendo chegar a aproximadamente 30% com medidas como uso exclusivo de biomassa como fonte de energia, ainda não possível no setor. As reduções no concreto podem chegar a 30%, pelo aumento no rigor na preparação deste material e pela redução de desperdício. Demonstrou-se, nesta pesquisa, que es se patamar de redução é tão significativo quanto o do setor cimenteiro. / The Brazilian concrete sector contributes to the climate change due to its CO2 emissions, that can be reduced through efforts of the cement sector, that have been receiving great attention. But the use of the cement in concrete can increase its consumption if made in the wrong way, and this can increase the CO2 emissions, making important the study of the emissions in concrete and the study of the possibilities of mitigation. These were the main aims of this thesis, that demonstrated that the CO2 reduction potential in the concrete have the same magnitude of the potential in the cement. The emission in the concrete, in Brazil, is 224 kgCO2/t. In cement, is 659 kgCO2/t, that is lower than the global emission and can be reduced by changes in the fuels used in the cement production. The Brazilian cement sector can reduce its emission in 20% and, using only biomass as fuel, this reduction can reach 30%, but this is not possible, yet. Emission reduction in the concrete production and use may reach 30%, through better preparation of concretes and reducing waste of material in constructions. This value is similar to the emission mitigation in the cement sector.
14

An analysis of the relationship between Carbon-Dioxide Emissions and Gross Domestic Product For 139 countries within the time period 1985-2004

Homoródi, Réka, Osmólska, Katarzyna January 2009 (has links)
The purpose of this dissertation would be to find the relationship between CO2 emission and GDP. We found that in case of the majority of countries the CO2 emission is related to national income and follows an inverted-U shaped curve. In our analysis we used the regression technique on 139 countries within the time period 1985-2004 to model and analyze the mentioned relationship and define the variables, that describe it. As it will be proved, Environmental Kuznets Curve validate the model and our hypothesis confirm other researches, therefore the inverse-u relationship proves to be correct.
15

Optimal Generation Expansion Planning Strategy for the Utility with Independent Power Producer Participation and Green House Gas Mitigation

Liao, Bo-xiang 29 June 2009 (has links)
Thermal power plants dominate electric power generation in Taiwan, which causes high Green House gases (GHG) emissions. CO2 is the most important greenhouse gas that cause global warming and sea-level to rise. This paper faces the relationship between CO2 limitation and power generation expansion planning (GEP) for the utility. Modify Particle Swarm Optimization (MPSO) is presented to determine the generation expansion planning strategy of the utility with independent power providers (IPPs). The utility has to take both the IPPs¡¦ participation and environmental impact into account when a new generation unit is expanded. This problem also takes into account the CO2 reduction and reliability issues, while satisfying all electrical constraints simultaneously from the supply point of view. MPSO scheme was improved to avoid getting a premature answer. Testing results shows that MPSO can offer an efficient way in determining the generation expansion planning. Generation expansion planning is an important decision-making activity in a competitive market, all utilities including IPPs need to maximize the profit while meeting the load demand with a pre-specified reliability criterion. In order to achieve the objective, utilities will perform the generation expansion planning to determine the minimal-cost capacity power addition. For better economy and efficiency, they will consider options of either constructing new generating units or purchasing electricity from other utilities or IPPs.
16

An analysis of the relationship between Carbon-Dioxide Emissions and Gross Domestic Product For 139 countries within the time period 1985-2004

Homoródi, Réka, Osmólska, Katarzyna January 2009 (has links)
<p> </p><p>The purpose of this dissertation would be to find the relationship between CO<sub>2</sub> emission and GDP. We found that in case of the majority of countries the CO<sub>2 </sub>emission is related to national income and follows an inverted-U shaped curve. In our analysis we used the regression technique on 139 countries within the time period 1985-2004 to model and analyze the mentioned relationship and define the variables, that describe it. As it will be proved, Environmental Kuznets Curve validate the model and our hypothesis confirm other researches, therefore the inverse-u relationship proves to be correct.</p><p> </p>
17

Quantifying CO2 emissions from lakes and ponds in a large subarctic catchment

Salimi, Shokoufeh January 2013 (has links)
Quantifying carbon emissions of water bodies at regional scale is required as recent studies revealed their contribution in carbon cycling is significant. This demands to scale up water bodies carbon emissions from local to regional scale using as accurate approach as possible. In this study data of carbon (CO2-C) fluxes for 80 sampled lakes were used to scale up to more than 3000 lakes and ponds over the catchment. The most appropriate method for upscaling was the one in which two factors of water body size and location (altitude) were involved and the uncertainties were quantified in an advanced approach (Monte Carlo model). Based on the estimates obtained in this method, the annual carbon emission from all water bodies (~ 500 km2) was about 2900 ton C yr-1 . About 62% of this annual emission was related to the large lake Torneträsk (334 km2) and another 38% to all other lakes and ponds (166 km2). Water bodies in subalpine region dominated (90%) total water bodies area and were the major contributor (97%) to the total carbon emissions of all water bodies. The remaining small contribution (3%) was for water bodies in the alpine region, which contains only 10% of total water bodies area. These data indicate that all water bodies smaller than the large lake Torneträsk especially the ones in the subalpine region have considerable contribution to the annual carbon emission of all water bodies. Considering water body size and altitude factors in the advanced upscaling method was appropriate to obtain accurate estimates.
18

CONTEÚDO ENERGÉTICO E EMISSÕES DE CO2 EM COBERTURAS VERDES, DE TELHA CERÂMICA E DE FIBROCIMENTO: ESTUDO DE CASO / EMBODIED ENERGY AND CO2 EMISSIONS IN GREEN ROOFS, CERAMIC TILES, AND FIBER CEMENT: CASE STUDY

Pereira, Marcos Fabricio Benedetti 15 April 2014 (has links)
CO2 is one of the main gases accountable for the increment of the greenhouse effect, of climate changes, and of environmental degradation arising from this ecological unbalance. Civil construction is one of the main sources of CO2 emissions, using construction techniques that are more sustainable can contribute to the reduction of those emissions. Furthermore, the energy content of materials must be taken into account as well due to the fact that the consumption of petroleum by-products increases the CO2 indexes in the atmosphere. It becomes then clear that the less energy is consumed, even those renewable, the less environmental impact there is. Thus, it is indispensable to analyse not only the emissions of CO2 but also the energy content of materials used in three roofing technologies under scrutiny in this research: green roofs, fibre cement, and ceramic tiles. Green roofs are a sustainable alternative to be implemented in covering the top of buildings. This research, therefore, aims to compare the CO2 emission to the energy content of two green roof solutions and of two traditional coverage solutions in the pre-operational phase in the cities of Porto Alegre and Santa Maria, both in the state of Rio Grande do Sul. The method used to identify left from the layers and constituents in each green cover, and the raw materials used in traditional roofs, measuring how much material was used for each cover, analyzing all the material traversed by the means of transport, quantifying emissions CO2 and energy consumption of materials by processes fabrication them and finally to compare all results. Common belief is that green roofs have the potential to mitigate environmental damages, especially those caused by the civil construction sector concerning CO2 emissions and energy consumption in the pre-operational phase, just as advantages in the operational phase are described. Such hypothesis was confirmed for the tested cover. However, among the possibilities discussed below for closing the top of buildings, green roofs are the only technology capable of mitigating environmental damage, in particular, the emission of carbon dioxide, and provide an environmental service to the community carbon sequestration to throughout his life . Nonetheless, amongst the building coverage possibilities herein analysed, green roofs are the only technology capable of integrally mitigating environmental damages in a few years, especially the emission of carbon dioxide, and also the only technology capable of providing an environmental service to the collectivity of carbon sequestration to throughout his life. / O CO2 é um dos principais gases responsáveis pelo incremento do efeito estufa, das mudanças climáticas e da degradação ambiental decorrente deste desequilíbrio ecológico. Sendo a construção civil uma das principais responsáveis pela emissão de CO2, o uso de técnicas construtivas mais sustentáveis pode contribuir para a redução dessas emissões. Além disso, o conteúdo energético dos materiais também é importante ser considerado, pois além de incrementar, através de consumo de derivados de petróleo, os índices de CO2 na atmosfera, o menor consumo de energia possível, mesmo as renováveis, representa menores impactos ambientais. Assim sendo, imprescindível analisar não só a emissão de CO2, como também o conteúdo energético dos materiais empregados nas três tecnologias de cobertura objetos de estudo desta pesquisa: coberturas verdes, de fibrocimento e de telhas cerâmicas. As coberturas verdes são uma possibilidade sustentável a ser implementada no fechamento de topo de edificações. A presente pesquisa visa a comparar as emissões de CO2 e o conteúdo energético de duas soluções de cobertura verdes e duas soluções de coberturas tradicionais, na fase pré-operacional, localizadas em Porto Alegre e outra em Santa Maria RS. O método utilizado partiu desde identificar as camadas e elementos constituintes em cada cobertura verde, bem como os insumos utilizados nas coberturas tradicionais, mensurar quanto material foi utilizado para cada cobertura, analisar o percorrido de todos os materiais pelos meios de transportes, quantificar as emissões de CO2 e o consumo energético dos materiais pelos processos de fabricações dos mesmos e finalmente comparar todos os resultados. O senso comum considera que as coberturas verdes têm o potencial de mitigar danos ambientais, especialmente os causados pelo setor da construção civil de emissão de CO2 e de consumo energético na fase pré-operacional, da mesma forma como são descritas as vantagens na fase operacional. Tal hipótese se confirmou para as coberturas avaliadas. Dentre as possibilidades aqui analisadas para fechamento de topo de edificações, as coberturas verdes são a única tecnologia capaz de mitigar os danos ambientais, em especial, a emissão de dióxido de carbono, e fornecer um serviço ambiental à coletividade de sequestro de carbono ao longo de sua vida útil.
19

Potenziale der Beschaffung von Ökostrom in Kommunen

Günther, Edeltraud, Klauke, Ines 17 January 2008 (has links)
Die Energieerzeugung aus fossilen Brennstoffen trägt weltweit erheblich zum Treibhauseffekt bei. So entfielen 2005 24 % der gesamten CO2-Emissionen in der Europäischen Union auf die Stromerzeugung aus Kohle [1]. Recherchen im Rahmen eines Forschungsvorhabens an der Professur für Betriebliche Umweltökonomie der TU Dresden ergaben, dass öffentliche Gebietskörperschaften einen Anteil von ca. 7,8 % am Stromverbrauch in Deutschland haben. Bisher berücksichtigen jedoch nur wenige Kommunen die CO2-Emissionen als Entscheidungskriterium bei der Ausschreibung von Strom. Damit wird deutlich, welches Potenzial in der Ausschreibung von Strom liegen kann. Hierbei stellt sich allerdings nicht nur die Frage, welche Herausforderungen öffentliche Ausschreibungen mit sich bringen, sondern auch wie diese Möglichkeiten den Markt aus der Sicht des Nachfragers eingrenzen, d. h. ob überhaupt ein entsprechendes Angebot am Markt verfügbar ist. / Energy supplies on the basis of fossil fuels contribute significantly to the global greenhouse effect. In 2005, for example, 24 % of the total CO2 emissions in the EU were attributable to coal-fired power generation. The work of a research project at TU Dresden revealed that public administrative bodies account for approx. 7.8 % of electricity consumption in Germany. To date, however, only few communities have made CO2 emissions a decision criterion in their electricity procurement. It is thus clear, just how much potential lies in the procurement process for electricity. At the same time, however, consideration must be given not only to the challenges arising from the appraisal of public procurement, but also to how these options limit the market scope from the point of view of the community, i.e. whether corresponding offers are actually available on the market.
20

Spatial distribution of residential solid waste generation in Brazil: estimating residential solid waste generation and CO2eq emissions based on the nominal income, towards the achievement of the Sustainable Development Goals

Redivo, Andre Luciancencov 22 July 2021 (has links)
The generation of solid waste is a natural consequence of human life. Its rate has increase rapidly along the years, mostly due to the population growth, urbanization process coupled to industrialization and economic development. The uncontrolled disposal of solid waste in unsuitable sites, dump sites, has poses a threat to public health and the environment. In this regard Global efforts has been made to rethink municipal solid waste management toward sustainability. Middle- and low-income countries, such as Brazil, should seize the opportunity and centre efforts in the development and strengthen of an inclusive municipal solid waste management, supported by an innovative public policy where all government levels are integrated and focused on resource recovery and recycling through the organization and strengthening of waste pickers, in order to act directly in the income improvement of a marginalized portion of society as a result of the revenue generated by recovered and recycled materials sales, as well as reduce the CO2eq emissions consequent from the disposal of solid waste, among others, hence moving these countries towards the achievement of the SDG goals. In this regard, a well managed inclusive municipal solid waste system requires a reliable data source to support decision makers in the design of public policies with effective actions in the field, otherwise innovative and modern public policies will be filled with fruitless actions, thus, wasting the aptitude of the municipal solid waste management system in help middle- and low-income countries to successfully carry out the SDGs goals. Nevertheless, the estimation methods are a valuable tool for decision makers in middle- and low income countries to outrun the lack of solid waste information and doing so, increase the effectiveness of public polices towards a sustainable and inclusive municipal solid waste system, focused on mitigate negative impacts in the environmental sphere and potentiate the positive outcomes in the public health and human development sphere in these countries. This research proposed an estimate method based on the nominal income which is able to provide a reliable estimate of the residential solid waste generation, as well as its spatial distribution in the municipal level and within the municipal boundaries. The proposed approach has the ability to differentiate spatial distribution of the residential solid waste generation, weighting not just the number of people living in a determined space, but also the purchase power of those people, providing a more accurate view of the issue, which benefits decision makers to design and plan their polices and actions. / Graduate

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