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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.
1

Consideration of life cycle energy use and greenhouse gas emissions for improved road infrastructure planning

Miliutenko, Sofiia January 2016 (has links)
Global warming is one of the biggest challenges of our society. The road transport sector is responsible for a big share of Greenhouse Gas (GHG) emissions, which are considered to be the dominant cause of global warming. Although most of those emissions are associated with traffic operation, road infrastructure should not be ignored, as it involves high consumption of energy and materials during a long lifetime. The aim of my research was to contribute to improved road infrastructure planning by developing methods and models to include a life cycle perspective. In order to reach the aim, GHG emissions and energy use at different life cycle stages of road infrastructure were assessed in three case studies using Life Cycle Assessment (LCA). These case studies were also used for development of methodology for LCA of road infrastructure. I have also investigated the coupling of LCA with Geographic Information Systems (GIS) and the possibility to integrate LCA into Environmental Impact Assessment (EIA) and Strategic Environmental Assessment (SEA). The results of the first case study indicated that operation of the tunnel (mainly, lighting and ventilation) has the largest contribution in terms of energy use and GHG emissions throughout its life cycle. The second case study identified the main hotspots and compared two methods for asphalt recycling and asphalt reuse. The results of the third case study indicated that due to the dominant contribution of traffic to the total impact of the road transport system, the difference in road length plays a major role in choice of road alternatives during early planning of road infrastructure. However, infrastructure should not be neglected, especially in the case of similar lengths of road alternatives, for roads with low volumes of traffic or when they include bridges or tunnels. This thesis contributed in terms of foreground and background data collection for further LCA studies of road infrastructure. Preliminary Bill of Quantities (BOQ) was identified and used as a source for site-specific data collection. A new approach was developed and tested for using geological data in a GIS environment as a data source on earthworks for LCA. Moreover, this thesis demonstrated three possible ways for integrating LCA in early stages of road infrastructure planning. / <p>QC 20160329</p>
2

Overseas Chinese students’ attitudes toward the role of China in the circumstance of global climate change

Hu, Jing January 2013 (has links)
Global climate change is becoming increasingly evident. There has been increased attention paid to the impact of human activity on climate. As a rising power, China’s energy needs to fuel its rapid economic growth with the resulting potential impacts of climate change presents an enormous climate policy dilemma not only for China but also for the entire world. The role of China is an issue of perennial concerns at the international climate change negotiation: its energy saving, emission reduction and clean production reflect China’s dual objectives about sustainable development and efforts on international legal obligations.Education abroad is an integral part of China’s development strategy. The abroad Chinese students who possess the knowledge, technologies skills and ideas, as well as information are playing an important role to assist China retain or increase its competitive advantage. The aim of this paper is to analyze the abroad Chinese students’ opinion on China’s role under the circumstance of global climate change, with main focus on three aspects: Energy consumption and environment situation in China; Several current domestic policies regarding problems of climate change and energy consumption in China; Issues facing the country on its road map to future mitigation action regarding climate change.Alongside the interviews carried out within ten overseas Chinese students, using the social science of Science, Technology and Society (STS) especially its public understanding of Science and Technology as the theoretical perspective, this thesis is exploring the interviewees’ attitudes toward current China’s climate change related issues from a deeper sense of human, culture and public perspective.
3

Evaluation Of State Owned Indigenous Coal Fired Power Plants Including Coal Reserves

Guler, Mehmet 01 February 2010 (has links) (PDF)
Fossil fuels has preserved their importance in gradually increasing production and consumption of both energy and electricity of the world. Asia, especially China and India, has arisen new actors of the sector. Energy and electricity consumption of Turkey has also increased in parallel with her economic development, but due to her limited resources, she has become more and more energy dependent in order to meet her growing demand. Although hard coal is only found around Zonguldak region, with its abundant and widely spread reserves, Turkey ranked world&rsquo / s third place in lignite production in 2008. Having low calorific value together with high ash and moisture content, most of lignites extracted is being consumed in thermic power plants located near those reserves. In the first two chapters of this study, energy in the world and Turkey will be considered seperately, then coal resources in Turkey will be analysed in the next coming chapter. Indirect and direct greenhouse emissions presented to the UNFCCC will be handled in the fifth chapter In the last chapter, first past and present performances of all indigenous coal fired power plants will be analysed, then after projecting their generation and fuel needs, they are evaluated considering with the reserves they are located. Finally, at the end of decomissioning of those power plants, remaining reserves will be re-evaluated and additional new units will be proposed accordingly.
4

Understanding the potential future capacity of distributing green steel solutions - current knowledge and future challenges

Alwan, Heba January 2023 (has links)
Transitioning from the conventional steel process to a direct hydrogen reduction process in the steel industry is a significant step towards reducing carbon dioxide emissions and achieving greater sustainability. The process involves using hydrogen gas as a reducing agent instead of carbon to remove oxygen from the iron ore. This study aimed to investigate the future capacity of the hydrogen-based steelmaking process in Sweden by 2050 while also examining the pathway for transitioning to hydrogen-based steelmaking in other European countries in comparison to the Swedish case. To achieve this goal, a systematic literature search was conducted using Scopus and Web of Science databases to identify relevant case studies and reviews that focused on green steel solutions and that discussed associated challenges and barriers. A aconsupteal model was designed by simplifying the process into three production steps, hydrogen storage, and hot briquette iron storage to calculate the energy consumption and material requirements for the hydrogen direct process in Sweden. Additionally, a survey providing insights regarding current practices and perspectives was administered to seven companies in Sweden and two in other European countries, namely the Netherlands and Germany. Furthermore, a comparative analysis of the literature review on life cycle assessment was conducted to compare the carbon emissions associated with two different steel production processes: the conventional process using the basic oxygen furnace and the emerging hydrogen-based steel production process.  An analysis of the energy consumption within the hydrogen-based steelmaking process reveals several components, including the electrolyze, direct reduction shaft furnace, electric arc furnace, and briquetted iron and hydrogen storage. The model results showed that electrolyzing alone accounts for 60% of the energy needed in the process. The model showed that hydrogen direct reduction steelmaking needs 3.66 MWH of electricity per ton of liquid steel produced in Sweden.  Only a few of the Swedish companies have adopted innovative approaches while the remaining steel mills primarily rely on scrap-based methods. While they may obtain hydrogen-reduced iron as a raw material in the future, emissions reduction is not their primary focus. These mills contribute to emissions through fuel usage, and efforts are underway to transition from fossil fuels to electricity, bio -based gas, or hydrogen. Hydrogen-based steel production produces significantly lower greenhouse gas emissions than conventional steel productio, by up to 90 percent, depending on the specific process and energy used, as stated in the life cycle analysis reviews.  This thesis shows key factors for the success of hydrogen-based steel production methods; low -emission electricity and flexibility to store hydrogen. All three countries have expressed interest in and invested in hydrogen-based steelmaking. the share of renewable energy produced and consumed in hydrogen-based steel production in Sweden is expected to make up a share of 2.3% of the total renewable energy production in the country, while Germany and the Netherlands are projected to contribute a modest 1.5% and 1.3% respectively. However, the search for ways to lower carbon dioxide emissions is costly in terms of the amount of electricity required. There are practical reasons for the restricted usage of this steelmaking process in Europe, including the availability of steel scrap, electricity demand, and the low likelihood of scrap generation and recycling scrap availability on the EU  market. Because of this, it is challenging to predict capacity and carbon dioxide reduction by 2050.
5

Electricity carbon intensity in European Member States: Impacts on GHG emissions of electric vehicles

Moro, Alberto, Lonza, Laura 21 December 2020 (has links)
The Well-To-Wheels (WTW) methodology is widely used for policy making in the transportation sector. In this paper updated WTW calculations are provided, relying on 2013 statistic data, for the carbon intensity (CI) of the European electricity mix; detail is provided for electricity consumed in each EU Member State (MS). An interesting aspect presented is the calculation of the GHG content of electricity traded between Countries, affecting the carbon intensity of the electricity consumed at national level. The amount and CI of imported electricity is a key aspect: a Country importing electricity from another Country with a lower CI of electricity will lower, after the trade, its electricity CI, while importing electricity from a Country with a higher CI will raise the CI of the importing Country. In average, the CI of electricity used in EU at low voltage in 2013 was 447 gCO2eq/kWh, which is the 17% less compared to 2009. Then, some examples of calculation of GHG emissions from the use of electric vehicles (EVs) compared to internal combustion engine vehicles are provided. The use of EVs instead of gasoline vehicles can save (about 60% of) GHG in all or in most of the EU MSs, depending on the estimated consumption of EVs. Compared with diesel, EVs show average GHG savings of around 50% and not savings at all in some EU MS.

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