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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.
301

En jämförelse av tre olika tillvägagångssätt för att kvantifiera utsläpp av växthusgaser : En studie om tillvägagångssättens användbarhet för Sveriges statliga myndigheter / A comparison of three different approaches to quantifying greenhouse gas emissions : A study on the usability for Swedish government agencies

Johansson, Patrik January 2018 (has links)
Det finns ett uttalat önskemål inom Sveriges statliga myndigheter är att finna lämpliga tillvägagångssätt för att kvantifiera växthusgaser, som en del i arbetet mot målet att bli förebilder inom miljöledningsarbete. Tillvägagångssätt som är praktiskt genomförbara, användbara och uppfyller myndigheternas behov och önskemål. Den här studien syftar till att identifiera och jämföra olika tillvägagångssätt för att kvantitativt bedöma utsläpp av växthusgaser. Det finns olika internationella etablerade tillvägagångssätt och i detta arbete studeras dess likheter och skillnader, föroch nackdelar. Den svenska statliga myndigheten SMHIs behov och önskemål exemplifieras i studiens frågeställningar och resultat. Studien är baserad på en litteraturstudie och material har bearbetats genom en analytisk induktion, där induktiv och deduktiv process använts. De etablerade riktlinjer och ramverk som valts ut att analyseras är Global Reporting Initiative (GRI), ISO-14064 och 2006 IPCC riktlinjerna. GRI används inte enbart till miljörelaterade frågor, det innehåller även perspektiv på sociala och ekonomiska frågor. Det innebär att det innehåller fler hållbarhetsperspektiv än IPCC 2006 och ISO 14064, då de enbart fokuserar på miljöperspektivet. I denna studie identifierades för- och nackdelar med samtliga valda tillvägagångssätt och vilket som lämpar sig för en statlig myndighet i Sverige beror vad myndigheten har för syfte. Är syftet att arbeta med att enbart kvantitativt bedöma skulle ISO 14064 eller IPCC 2006 vara applicerbara. Om syftet är att arbeta med alla perspektiv inom hållbarhet, så är GRI applicerbart. Det beror också på i vilken skala myndigheter vill göra sina bedömningar, på lokal, regional eller nationell nivå, eftersom den geografiska skalnivån skiljer mellan ISO 14064 och IPCC 2006. / There is a pronounced need within Swedish government agencies to find approaches for quantifying greenhouse gases, as part of their work towards the goal of becoming role models in environmental management. Approaches that are practically feasible, useful and meet the government agencies needs and wishes. This study aims to identify and compare different approaches to quantitatively assessing greenhouse gas emissions. There are different international established approaches, and this thesis has studied their similarities and differences, as well as pros and cons. The Swedish Government agencies SMHI's needs and wishes are exemplified in this study's questions and results. The study is based on a literature study and material has been processed through an analytical induction, using inductive and deductive processes. The established guidelines and framework chosen to be analyzed are Global Reporting Initiative (GRI), ISO 14064 and 2006 IPCC Guidelines. GRI is not only used for environmental issues, it also includes perspectives on social and economic issues. This means that it contains more sustainability perspective than IPCC 2006 and ISO 14064, who only focusing on the environmental perspective. This study identified the pros and cons of all the chosen approaches and if it is appropriate for a governmental agency depends. Is the purpose of working to quantitatively measure the ISO 14064 or IPCC 2006 is applicable. If the purpose is to work with all sustainability perspectives, GRI is applicable. It also depends on what scale government wants to make its calculations, at local, regional, or national level, as the geographic level of scale differs between ISO 14064 and IPCC 2006
302

Avaliação de impactos da inserção dos veículos elétricos nos sistemas de distribuição das concessionárias EDP Bandeirante e EDP ESCELSA. / Evaluation of the electric vehicles impact on the distribution systems of the EDP Bandeirante and EDP ESCELSA utilities.

João Paulo Niggli Silva 21 March 2014 (has links)
O objetivo deste trabalho é avaliar qual seria o impacto da inserção dos veículos elétricos nos sistemas de distribuição de energia elétrica de duas distribuidoras brasileiras, a EDP Bandeirante e EDP ESCELSA. Como esta tecnologia ainda não se encontra em utilização no Brasil, será adotada uma abordagem prospectiva, de modo a projetar o crescimento da frota de veículos elétricos até o ano de 2020. Para que se possa simular em uma sub estação, qual será o impacto da adoção desta tecnologia. Utilizando-se das projeções de crescimento da frota, também serão quantificados o impacto na matriz energética nacional e nas emissões de gases do efeito estufa. / This work, aims to evaluate the impact of the electric vehicles insertion on two power distribution utilities, EDP Bandeirante and EDP ESCELSA. How the electric vehicles aren´t a reality on Brazil, an prospective approach will be adopted, to project the growth of the electric vehicles fleet until the 2020 year, so that can be simulated in one substation, the impact that would be caused by the adoption of this technology. Using these projections, the impact on Brazilian energetic matrix, and the greenhouse gas emissions will be calculated to.
303

Avaliação de impactos da inserção dos veículos elétricos nos sistemas de distribuição das concessionárias EDP Bandeirante e EDP ESCELSA. / Evaluation of the electric vehicles impact on the distribution systems of the EDP Bandeirante and EDP ESCELSA utilities.

Silva, João Paulo Niggli 21 March 2014 (has links)
O objetivo deste trabalho é avaliar qual seria o impacto da inserção dos veículos elétricos nos sistemas de distribuição de energia elétrica de duas distribuidoras brasileiras, a EDP Bandeirante e EDP ESCELSA. Como esta tecnologia ainda não se encontra em utilização no Brasil, será adotada uma abordagem prospectiva, de modo a projetar o crescimento da frota de veículos elétricos até o ano de 2020. Para que se possa simular em uma sub estação, qual será o impacto da adoção desta tecnologia. Utilizando-se das projeções de crescimento da frota, também serão quantificados o impacto na matriz energética nacional e nas emissões de gases do efeito estufa. / This work, aims to evaluate the impact of the electric vehicles insertion on two power distribution utilities, EDP Bandeirante and EDP ESCELSA. How the electric vehicles aren´t a reality on Brazil, an prospective approach will be adopted, to project the growth of the electric vehicles fleet until the 2020 year, so that can be simulated in one substation, the impact that would be caused by the adoption of this technology. Using these projections, the impact on Brazilian energetic matrix, and the greenhouse gas emissions will be calculated to.
304

Modeling Electric Vehicle Energy Demand and Regional Electricity Generation Dispatch for New England and New York

Howerter, Sarah E 01 January 2019 (has links)
The transportation sector is a largest emitter of greenhouse gases in the U.S., accounting for 28.6% of all 2016 emissions, the majority of which come from the passenger vehicle fleet [1,2]. One major technology that is being investigated by researchers, planners, and policy makers to help lower the emissions from the transportation sector is the plug-in electric vehicle (PEV). The focus of this work is to investigate and model the impacts of increased levels of PEVs on the regional electric power grid and on the net change in CO2 emissions due to the decrease tailpipe emissions and the increase in electricity generation under current emissions caps. The study scope includes all of New England and New York state, modeled as one system of electricity supply and demand, which includes the estimated 2030 baseline demand and the cur- rent generation capacity plus increased renewable capacity to meet state Renewable Portfolio Standard targets for 2030. The models presented here include fully electric vehicles and plug-in hybrids, public charging infrastructure scenarios, hourly charging demand, solar and wind generation and capacity factors, and real-world travel derived from the 2016-2017 National Household Travel Survey. We make certain assumptions, informed by the literature, with the goal of creating a modeling methodology to improve the estimation of hourly PEV charging demand for input into regional electric sector dispatch models. The methodology included novel stochastic processes, considered seasonal and weekday versus weekend differences in travel, and did not force the PEV battery state-of-charge to be full at any specific time of day. The results support the need for public charging infrastructure, specifically at workplaces, with the “work” infrastructure scenario shifting more of the unmanaged charging demand to daylight hours when solar generation could be utilized. Workplace charging accounted for 40% of all non-home charging demand in the scenario where charging infrastructure was “universally” available. Under the increased renewable fuel portfolio, the reduction in average CO2 emissions ranged from 90 to 92% for the vehicles converted from ICEV to PEV. The total emissions reduced for 15% PEV penetration and universally available charging infrastructure was 5.85 million metric tons, 5.27% of system-wide emissions. The results support the premise of plug-in electric vehicles being an important strategy for the reduction of CO2 emissions in our study region. Future investigation into the extent of reductions possible with both the optimization of charging schedules through pricing or other mechanisms and the modeling of grid level energy storage is warranted. Additional model development should include a sensitivity analysis of the PEV charging demand model parameters, and better data on the charging behavior of PEV owners as they continue to penetrate the market at higher rates.
305

Ontario feedlot operators' willingness to accept carbon credit revenue for adopting management practices that reduce greenhouse gas emissions

Hristeva, Polina. January 2007 (has links)
No description available.
306

Subsurface re-injection of carbon dioxide for greenhouse gas control: influence of formation heterogeneity on reservoir performance

Flett, Matthew Alexander January 2008 (has links)
The injection of carbon dioxide (CO2) into saline formations for the purpose of limiting greenhouse gas emissions has been proposed as an alternative to the atmospheric venting of carbon dioxide. In the evaluation process for selecting a potential target saline formation for the disposal of carbon dioxide, flow characterisation of the disposed plume should be undertaken by reservoir simulation of the target formation. The movement of injected carbon dioxide in the saline formation is influenced by many factors including the physics of carbon dioxide at deep formation depths and pressure, physical interactions with formation rock and pore water and variations in the rock flow pathways through changes in formation heterogeneity. This thesis investigates the roles of physical interactions on the disposal of carbon dioxide and the ability to contain the injected gas through evaluation of trapping mechanisms such as dissolution of CO2 in formation water and residual gas trapping through the process of gas-water relative permeability hysteresis. Variable formation heterogeneity is evaluated for its impact on the migration of injected CO2 plume movement and the role of formation heterogeneity in impeding or accelerating the immobilisation of injected carbon dioxide. Multiple reservoir simulation studies were conducted to evaluate, initially, the role of different trapping mechanisms in immobilising the movement of injected carbon dioxide and subsequently, the role of variations in formation rock in the migration and trapping of and injected plume of carbon dioxide. The major simulation study shows that the selection process for identifying appropriate saline formations should not only consider their size and permeability but should also consider their degree of heterogeneity endemic to the formation. / A set of reservoir performance metrics were developed for the CO2 disposal projects. The metrics were applied to compare plume migration of injected CO2 (both vertically and laterally) and containment (through dissolution and residual phase trapping) in these studies. The findings demonstrate how formation heterogeneity has a significant impact on the subsurface behaviour of the carbon dioxide. Formation dip influences the rate of migration, with low formation dipping reservoirs having slower rates of vertical migration. Increasing the tortuousity of the migration flow path by either increasing the shale (non-reservoir) content or lengthening the shale baffles in the formation (corresponding to a gradual decrease in reservoir quality), can progressively inhibit the vertical flow of the plume whilst promoting its lateral flow. The increase in the tortuosity of the CO2 migration pathway delays the migration of CO2 and increases the residence time for the CO2 in the formation. Thus, formation heterogeneity impedes the onset of residual gas trapping through hysteresis effects. Ultimately less carbon dioxide is likely to collect under the seal in heterogeneous formations due to increased reservoir contact and long residence times, thereby reducing the risk of seepage to overlying formations. / Given sufficient permeability for economic injection of CO2, then low to mid net-to-gross heterogeneous saline formations with low formation dip and lengthy intra-bedded shales are desirable for selection for the geological disposal of CO2. Detailed reservoir characterisation of any potential geological disposal saline formations is required in order to accurately predict the range of outcomes in the long term flow characterisation of injected CO2 into those formations.
307

Quantification of Greenhouse Gases at Visy Industries using Life Cycle Assessment

Wiegard, Jean, JWiegard@groupwise.swin.edu.au January 2001 (has links)
Greenhouse gases (GHGs) are vital components of the earth�s atmosphere, trapping heat around the earth, maintaining temperatures necessary for human existence. Until the Industrial Revolution, these gases existed in a natural equilibrium with the environment. Since that time, anthropogenic activities such as fossil fuel burning and land clearing have increased the quantity of GHGs, such as carbon dioxide (CO2) and methane (CH4), in the earth�s atmosphere. Evidence indicates that global warming is occurring as a result of the additional accumulation of GHGs in the atmosphere. International response to climate change resulted in the 1997 development of the Kyoto Protocol. If the Protocol is ratified, developed countries will be legally bound to reduce their GHG emissions in accordance with negotiated emission reduction targets. At the beginning of the year 2001, the Protocol was still to be ratified. With the possibility of future GHG emission restrictions, some Australian companies have started quantifying their GHG emission levels. One such company is Visy Industries, the largest privately owned paper packaging manufacturing company in the world. Visy�s core business is the manufacture of cardboard boxes from recycled paper. As part of its future operations, a kraft pulp and paper mill is presently being built in New South Wales, Australia. The environmental decision support tool, Life Cycle Assessment (LCA), was used to quantify Visy�s CO2 and CH4 emissions across the entire life cycle of the Visy paper recycling and virgin papermaking processes. Commercially defined LCA models were developed for both papermaking processes. GHG emissions estimated by each model were compared and the effect of different energy sources, technologies and manufacturing processes on CO2 and CH4 emissions were assessed. The majority of emissions in the two Visy papermaking models were due to fossil fuel derived energy sources and the decomposition of wood fibre in Solid Waste Disposal Sites (SWDSs). Results were used to propose appropriate GHG reduction strategies and business opportunities. GHG reduction strategies included increasing the use of renewable energy, reducing the volume of solid waste rejects sent to SWDS, incinerating solid waste rejects with energy recovery and sourcing steam from third party providers. Proposed GHG business opportunities included increasing the production of Greenpower from the pulp and paper mill for sale to the grid. This thesis is an example of the practical application of current GHG knowledge and LCA methodology that was undertaken in an environment where technical, political and commercial guidelines at both a national and international level were still evolving. Nevertheless, the thesis is not a critical review of LCA methodology. The LCA support tool was able to quantify CO2 and CH4 emissions across the life cycle of the Visy recycling and virgin papermaking processes. The chosen functional unit, the assumptions and exemptions made, and the placement of the system boundaries, were found to be critical to the Visy LCA results.
308

Quantifying variation in estimated methane emission from ruminants using the SF6 tracer technique : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, New Zealand

Vlaming, Johannes Bernardus January 2008 (has links)
With the signing of the Kyoto Protocol, New Zealand must reduce its national greenhouse gas emissions. As New Zealand has a large proportion of its national emissions as methane (~31%), and methane (CH4) has a short atmospheric lifetime, it provides a good target for mitigation strategies. The initial aim of this research was to identify high and low CH4-emitting cattle to assess factors that contribute to low CH4 production. Initial studies using the SF6 tracer technique to estimate CH4 production could not identify consistently high and low CH4 emitters. Research was therefore undertaken to confirm whether this was due to high variation in estimated CH4 yields, and to quantify the within- and between-animal variation in CH4 production when using the SF6 technique. This research showed considerable within- (coefficient of variation, CV = 7-10%) and between-animal (CV = 7-18%) variation in CH4 yield (g CH4/kg DMI) over time when using the SF6 technique. This is larger than the within- (CV = 3%) and between-animal (CV = 10%) variation reported for calorimetry. This led to the recommendation that the SF6 technique not be used in identifying animals for high or low CH4 yield. A power analysis was developed based on the measured variances for the SF6 technique. Results from this analysis provide researchers with important information on the number of animals and measurements per animal required when undertaking CH4 experiments. One of the sources of variation with the SF6 technique is the SF6 release from permeation tubes. Estimated CH4 yield increases by approximately 8.5% when going from a release rate of 3 mg SF6/day to a rate of 5 mg SF6/day. Further, an in vitro study indicated that SF6 release from permeation tubes is approximately 8% lower in rumen fluid than in air. While further research is required to confirm these results, they emphasise the need to allow time for the release rate to stabilise in the rumen for 4-5 days prior to undertaking measurements. It also led to the recommendation that release rates used in experiments should be within a narrow range, and balanced across experimental treatments.
309

Carbon capture and storage and the Australian climate policy framework

Goldthorpe, Ward Hillary January 2009 (has links)
Australia’s economy is heavily dependent on coal-based energy and greenhouse gas intensive natural resource extraction and processing industries. As part of an international climate change mitigation effort Australia will have to undergo a national transformation to a low emissions society by mid century. Federal and State Governments in Australia, like their counterparts in other major developed economies, have been persuaded that reliance on fossil fuels in stationary energy industries such as electricity generation and minerals processing will be able to continue with the deployment of a value chain of technologies fitted to these installations for capturing carbon dioxide, transporting it to a disposal site, and then injecting it into subsurface geological formations for permanent storage (carbon capture and storage, or CCS). Understanding the likely effectiveness of CCS for reducing greenhouse gas emissions from stationary energy industries is therefore critical to policy formulation for, and management of, Australia’s emissions mitigation effort and national transformation over the decades ahead. / This thesis aims to offer a clearer understanding of the practicalities, limitations and uncertainties surrounding future CCS use in Australia and of the contribution CCS can make to mitigating emissions from the Australian stationary energy sector in the period to 2050. It considers two central questions: Is CCS a realistic option for emissions mitigation in Australia? Are Australian climate policies formulated to facilitate CCS deployment and optimise its potential contribution? The criteria employed in this thesis for answering these questions are restricted to those having an ascertainable causal impact on the timing, pace and ultimate scale of CCS deployment within Australia. The methodology used for the research is grounded in critical approaches and integrated assessment within a holistic, trans-disciplinary paradigm. / This thesis finds that under Australia’s existing climate policy framework it is unrealistic to expect CCS can contribute more than 75 million tonnes of CO2 per annum to emissions mitigation by 2050. Australia does have sufficient potential geological storage resources to expect some environmentally safe CCS infrastructure could be engineered over time, but commencement of large scale build-out is not likely before 2025. When CCS will become a commercial mitigation option in Australia is unpredictable and dependent more on the political economy of climate change than on Australian research, development and demonstration activities. / The thesis also finds that the existing climate policy framework is increasing rather than decreasing the risks to timing and usefulness of CCS even to the level of 75 million tonnes of CO2 per annum by 2050. This thesis concludes that Australian Governments are not developing the institutional capability to oversee a holistic decarbonisation of the stationary energy sector. This capability is required not only to address the risks to CCS deployment but also to prevent market failures that foreclose an optimal contribution from all other potential mitigation technologies. The thesis proposes that an Australian national CCS company be created with responsibility for CCS integration, transport and storage services in order to develop Australian capability rather than that of international corporations.
310

Biogeochemical Cycling and Microbial Communities in Native Grasslands:Responses to Climate Change and Defoliation

Attaeian, Behnaz 06 1900 (has links)
Ongoing climate change has emerged as a major scientific challenge in the current century. Grassland ecosystems are considered net carbon (C) sinks to mitigate climate change. However, they are in turn, influenced by climate change and management practices, providing feedback to climate change via soil microbial community and biogeochemical fluxes. In this thesis, I examined the impact of warming, altered precipitation, and defoliation on soil microbial composition and function, C and N dynamics, and fluxes in soil respiration (CO2), nitrous oxide (N2O) and methane (CH4), together with other belowground ecosystem functions, within two ecosites in a northern native temperate grassland in central Alberta, Canada, over a two-year period. Fungi-to-bacteria ratio was not affected by climatic parameters or defoliation, indicating a high degree of resistance in the below ground community to the treatments imposed. However, C substrate utilization was influenced by warming and defoliation, as was soil microbial biomass. In contrast, soil respiration (or C loss) was not. Soil respiration acclimatized rather quickly to warming, and N2O and CH4 effluxes showed minor responses to warming at both ecosites, regardless of defoliation. These results suggest warming is unlikely to lead to positive climate change feedback due to soil-based responses, regardless of ongoing land use. However, altered precipitation ( 50%) demonstrated greater impacts on C and N fluxes relative to warming and defoliation. Increased precipitation stimulated soil C loss to the atmosphere, potentially generating positive feedback for climatic warming in this northern temperate grassland. / Soil Science

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