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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.
41

Life Cycle Assessment of a Single-Family Residence built to Passive House Standard

Dahlstrøm, Oddbjørn January 2011 (has links)
Two complete cradle to grave life cycle assessments are conducted for the comparison of a house built after today’s building standard, TEK07, and a passive house built after the Norwegian Standard NS 3700:2010. Both houses are projected by the building company Nordbohus AS, and are to be constructed in Stord, on the west coast of Norway. The usable floor area, BRA, is 187 m2 for both houses, and a lifetime of 50 years is assumed. The houses are constructed with a wooden framework, insulated with mineral wool in the walls and roof, and have a ground lever floor of reinforced concrete on a layer of expanded polystyrene. The passive house has, compared to the TEK07 house a different foundation, 15 cm more mineral wool in the outer walls, 5 cm more in the roof, and better insulated windows and doors. In addition, the thermal conductivity for the outer wall insulation is reduced for the passive house. The house life cycle is divided into several phases. Construction of the house, waste treatment of materials connected to the construction, surface finish and maintenance of the house during the lifetime, water and electrical energy consumption during the house operation and finally demolition and waste treatment of the materials after the end of the house lifetime. Transportation of workers and materials to the construction site, as well as to waste treatment plant, are included. Generic data from Ecoinvent 2.0 database is used, but some processes are modified to satisfy Norwegian production information. The Nordel electricity mix is used for Norwegian production and house electricity consumption. SimaPro 7.1.8 is used to process the data, and the ReCiPe method, hierarchist midpoint version 1.03 is used for the impact assessment. It is assumed that both houses have the same heating system, and cover 100% of the energy needs from electrical energy. For the 50 year life cycle, the passive house has 20% less impacts to climate change than the TEK07 house. For the other categories assessed, the passive house has between 10-20% lower impacts than the TEK07 house. The only exception is impacts to freshwater ecotoxicity, where the passive house impacts are increased with 7% from the TEK07 house. The TEK07 house has impacts to climate change with 1,6 tons CO2 eq/m2 useful floor, while the passive house 1,3 tons CO2 eq/m2 useful floor. Cumulative energy demand is 55 GJ/m2 and 42 GJ/m2 respectively. The construction phase is responsible for 13%, waste treatment of materials connected to construction 1%, surface finish and maintenance 6% and end of life waste treatment 4% of overall climate change impacts for the TEK07 house. Water and electricity consumption during the operation are thus responsible of 76% of the TEK07 life cycle climate change impacts. For the passive house, this is 19%, 1%, 7%, 6% and 67% respectively. Main activities contributing to the overall impacts are transportation of materials, workers and waste to and from the construction site, diesel combusted in building machines, production and incineration of EPS/XPS and paint, waste treatment of wood ash, and production of cement and ceramic tiles.A sensitivity analysis of energy consumed by the construction dryer, frequency of house maintenance, a change of house consumption electricity mix to the Norwegian and UCTE electricity mix, and a change to different heating systems for both houses is carried out.The overall conclusion is that it is environmentally beneficial to build, operate and waste treat a passive house compared to a house following the TEK07 building standard.
42

Life Cycle Assessment of Scenarios for the Icelandic Vehicle Fleet

Vignisdóttir, Hrefna Rún January 2011 (has links)
Environmental issues, foremost global warming and climate change, are attracting more and more attention in world’ discussion as the global community constantly works on an agreement for actions to limit it. Global warming and climate change are human induced greenhouse effects that are a direct result of burning fossil fuels. Global warming is not the only problem of using fossil fuels. It is estimated that recoverable fossil energy reserves can only meet the demand for energy until 2050, if demand stabilizes at a current level. Iceland has commitments to reduce emissions contributing to global warming and as the transportation sector makes up a considerable proportion of the total emissions therefore the analysis of that sector is important. The overall aim of this report is therefore to analyze the life cycle emissions of the Icelandic vehicle fleet from 1990 to 2010 and then to develop possible and necessary scenarios for the future development of the fleet. Emissions of the Icelandic vehicle fleet are calculated using a life cycle approach. First the historical model used to calculate past emissions is defined along with the relevant parameters. Additional parameters for the scenario model, for three different scenarios: the reference; the green and the target, are presented and further calculations explained. The results show that emissions in the reference scenario increases continually and by 2050 it is over three and a half times higher than the emission reduction target, while the green scenario, which assumes moderate measures, is over 2.6 times higher. The target scenario, being the only scenario getting close to the target, has a reduction in emissions at 67% by 2050 compared to 2010. The model gives a clear indication of the development of the service provided, and shows that there is little reduction in the population’s overall mobility in the reference and green scenarios, while the kilometers driven per person returns to 1990 level in the target scenario. The model indicates that reaching the emission reduction goal that the Icelandic government has announced seems very unlikely if all sectors are to reduce emissions equally. It is clear that action needs to be taken immediately in Iceland and elsewhere if international goals are to be kept.
43

Life cycle assessment of a pumped storage power plant

Torres, Octavio January 2011 (has links)
Wind and solar power plants are gaining increasing attention due to low green house gas emissions associated with electricity generation. The installed capacity of these resources is rapidly growing, while it is argued that the stability of the grid is threatened since these resources depend on actual weather conditions and their output cannot be easily adjusted to follow instantenous electricity demand. Another reliable low carbon power supply such as nuclear power plants cannot help in stabilizing the grid, due to long time constant of the control system. Eventhough, nuclear power is easy to predict, it needs external grid stabilizing utilities itself.If electricity could be stored in a sufficient amount during the periouds of favourable conditions for renewable energy sources and during periods of low demand for electricity and utilized again when it is demanded, the stability of the grid would be improved and no extra installed capacity of more carbon intensive power plants would be necessary. Therefore, an increasing focus is currently given on large scale energy storage. One of the most promising options for large scale energy storage which is already operating due to its fast response to electricity demand is a pumped storage power station. Before an extensive installation, it is important to evaluate this technology from the environmental perspective in order to avoid shifting environmental problems, to assess its potential to decrease dependency of electrical grids on fossil fuels and to estimate its potential in climate change mitigation/greenhouse gas reduction.
44

Life Cycle Assessment of platform chemicals from fossil and lignocellulosic biomass scenarios : LCA of phenolic compounds, solvent, soft and hard plastic precursors

Gallardo Hipolito, Martin January 2011 (has links)
One of the challenges of our time is the substitution of the existing fossil based economy by a green economy within the framework of sustainable development of our society. Biomass, especially from lignocelluloses, is a promising solution for the substitution of fuels, energy, chemicals and materials from fossil sources in a so called ―Biorefinery‖. The production of biochemicals presents higher mass and carbon theoretical efficiency, and it seems an interesting alternative to provide a renewable path for globally and widely demanded platform chemicals like phenols, solvents (Acetone), soft plastic precursor (Polyethylene) and hard plastic precursor (Polypropylene).In this report, the environmental loads associated to the production of biochemicals (Phenolic compounds, Acetone, PolyHydroxyButyric Acid and Polylactic Acid) from lignocellulose biomass scenarios (Poplar and Eucalyptus) are evaluated and compared to the petrochemical equivalents. Life Cycle Assessment Methodology and the latest Global Warming Potential Indicator that accounts biogenic greenhouse gas effect related to the rotation period of the feedstock along the entire carbon cycle are used along this study.Biochemicals production could contribute to possible reductions between 37% and 48% on greenhouse gas emissions for the functional unit when taking into account the entire carbon cycle and not only from cradle to gate. Also, up to 80% fossil fuel can be saved while ecotoxicity indicators present much lower values for biochemicals production. PHB seems to be the most environmentally friendly of all the biochemicals, and phenolic compounds the worst. But there are some trade-offs; biochemicals may increase other impact categories such Eutrophication and Acidification, but also Human toxicity, Photochemical Oxidant Formation and Particulate Matter Formation. Last but not least, water depletion is a fundamental issue involved, being substantially higher for biochemicals, even when irrigation of certain wood species may not occur. Decrease of fertilizers and irrigation, new solutions for disposal, treatment and recycling of ash and gypsum, increase of yields and production, energy efficiency techniques and a cleaner electricity mix, could bring the production of biochemicals to an status where they are dramatically better in all impact indicators if all the stakeholders on the life cycle of the biochemicals (Agriculture and Industry sectors, research institutions, policy makers and final customers) get involved.
45

Phosphorus management in the Baltic Sea – historic evidence and future options

Mehta, Shraddha January 2012 (has links)
Phosphorus being one of the essential elements for all forms of life is also a finite resource. The extensive use of Phosphorus in anthropogenic activities has lead to high nutrient load in surface waters causing eutrophication. The Baltic Sea being a semi enclosed water body and a good example of eutrophication has been chosen as model basis. To determine the magnitude of phosphorus use in Riparian States and the total loads to the sea is investigated using a systems analysis approach. In this thesis the phosphorous flows were examined using substance flow analysis of two types of systems: anthropogenic system and a sub basin system. The anthropogenic system presents the flows and stocks of phosphorus within processes with phosphorus utilization within each Riparian country and the total load of phosphorus to the Baltic Sea. The sub basin system models individual sub basins to determine the total input of phosphorus and the resident stocks of phosphorus in sea water and biomass. Based on the sub basin a hypothesis is formulated to determine the fate of phosphorus in the sea and the identify sinks of phosphorus. Hypothesis: The inflow of phosphorus into the Baltic Sea is not coupled with an increase in phosphorus stock but result in a high sedimentation rate. The sub basins represent phosphorus exporters to other neighboring basins. Within the anthropogenic system, agriculture and food market posses the largest flows and stocks of phosphorus. While the largest loads from the anthropogenic systems are from agricultural run off and waste water discharge. Poland is found to have major share in this contribution of phosphorus flows to the Baltic Sea. The sub basin Baltic Proper contains the largest stock of phosphorus among all the other sub basins. The test of the hypothesis hold true and sediments of the Baltic Sea have been recognized as major sinks of phosphorus.
46

Modelling environmental benefits of household waste prevention

Lèbre, Eléonore January 2012 (has links)
Waste prevention can be seen as a form of waste treatment, and it is then considered as the most desirable option to mitigate the environmental impacts of waste generation. However, some have already pointed out the fact that the true potential of waste prevention might lie in its connection to sustainable consumption, and not as a substitute to waste treatment (Ekvall 2008, Olofsson 2004). Sustainable consumption and waste prevention are concepts that are closely related. Goods that people consume always end up as waste. In some cases, waste prevention also results in reduced consumption and this is what was analysed in this master thesis. The aim is to assess the environmental benefits of household waste prevention by considering the overall production chain and not only the waste management system.To assess the benefits of waste prevention, a hybrid LCA model was developed. This model combines an Input Output Analysis of consumer expenditures with a Life Cycle Analysis of household waste generation. The Input Output Analysis is an appropriate tool to assess a basket of product categories that are expressed in monetary terms, as it is the case for household consumption. The Input Output dataset is connected to the Consumer Expenditure Survey which gathers a household’s total yearly purchases. The Life Cycle Analysis of a waste generation vector includes all data characteristic of the Waste Management System in Trondheim and the future of the waste is assessed from its collection and sorting to its recycling and use in secondary production.The scenarios chosen to evaluate the potential of waste prevention are targeting food, textiles and paper products. They all assume that waste prevention results in a proportional decrease in consumption, thus affecting both the LCA and the IOA results. The aim is to compare these two sets of results. In the IO scenarios, the influence of a rebound effect was also tested. Rebound effects are due to a constant income that settles the total amount of expenditure: scenarios generate reduced consumption and hence money savings that will still be spent on something else in the end. The ways they are re-spent will determin the final results. Various cases were tested: the rebound on holidays, restaurant, culture, repair, the marginal rebound and the simple rebound. The two latter ones distribute the savings on all categories.From this study the main results are the following:- The environmental benefits of waste prevention occur mostly at the production chain level: most changes occurring at the waste management level are 2 to 4% of the ones occurring upstream. Benefits generated by the waste management system are low and sometimes even negative, meaning that the reduction scenarios generated more impact than the reference scenario. This is because the Waste Management System generates environmental benefits on its own, thanks to energy recovery and material recycling that substitute primary production. Decreasing the amounts of waste collected hence reduces these benefits.- The influence of the rebound effects on the results is significant. In the case of global warming, the holiday rebound is the one that mitigates the most the initial benefits (they are reduced from 7% to 1% in the results that combine all scenarios together). The marginal and the simple rebounds come next. Rebounds on restaurant and culture are most of the time the most beneficial in the way that they reduce the benefits only from 7% to 5.5%. - Even though comparison between the different targeted categories is subject to uncertainties, one can still notice the importance of food, which generates significant benefits even though the consumption was only reduced by 11%. The results also show that preventing paper waste is the least beneficial scenario.
47

Life Cycle Assessment of Technical Solutions for High-Speed Rail: Tunnel and Track designs

Lia, Anne Margrethe January 2012 (has links)
On the 19th of February 2010, the Ministry of Transport and Communication presented the Norwegian National Rail Administration with the task of assessing different aspects of the future of high-speed rail in Norway. The report, the Norwegian High-Speed Rail Assessment (NHSRA), consist three separate evaluations where the climate assessment by Bergsdal et al. (2012), motivated this thesis. Results from the report identify the railway infrastructure as the dominant emission source for the corridor, with the length of tunnels representing the determining factor. Simultaneously, an ongoing debate is comparing the safety and performance of track and tunnel technologies traditionally used in Norway to that of foreign tunnelling technology such as the drill and blast method which apply a full cast (European method), and a double shielded tunnel boring machine (TBM). The newest development in track technology is the slab track, which is now evaluated for tunnels and bridges in Norway (Jernbaneverket 2011). This thesis contributes to the ongoing debate concerning the construction of infrastructure for high-speed rail in Norway, by emphasizing the environmental impact of several relevant technologies and geological conditions. The assessment includes an evaluation of the impact of different tunnelling and track technologies, calculated for operation speeds of both 250km/h and 330km/h. Further, the environmental impact of different levels of support work and grout is assessed. In addition, this thesis includes a sensitivity analysis of the impact of service life for railway components. The assessment is calculated for two functional units: one meter tunnel and tunnel track, and for the case corridor, the potential high-speed rail corridor between Oslo-Stavanger, estimated for 250km/h obtained from the NHSRA by Bergsdal et al. (2012).Our results from this assessment account for the use of cement, steel and copper as the environmentally most important materials. Among the railway components, the tunnel lining and grout constitute the highest emission level of the case corridor. The different technical alternatives are compared against the technologies traditionally applied in Norway, and an average level of support work, which represents the baseline results of this thesis. Our results indicate that the double shielded tunnel-boring machine is the technology that contributes to the highest increase of emission level compared to baseline. Further, the variables that hold the greatest potential of reducing total emission level is the installation of slab track in tunnels and bridges, and level of grout in the tunnel construction.
48

Nantes' and Oslo's urban water systems: Assessing benefits from water-energy nexus interventions. : Report number D1-2012-36

Vachon, Matthieu January 2012 (has links)
In this thesis is investigated the water-energy nexus, the intricate relation that exists between water use in energy, and energy use in water. Indeed, literature review shows the importance of this relation and the necessity to reduce the impact from the water utility’s side, the influence at the heart of this work.To lead such a study, the cases of two cities, Nantes and Oslo have been explored. Oslo is the capital of Norway, inhabited by 560,000 people in 2007, the baseline year for the study. This city benefits from an important economic and demographics dynamics, as it is attractive to both Norwegians from outside Oslo and foreigners. Nantes Métropole is a conurbation of 24 towns around Nantes, the administrative capital of the Region Pays de la Loire in France. Its population of 590,000 in 2010 (baseline year for Nantes) and its position make it an economic and demographic centre.In these two cities, it was possible to develop a model of the urban water cycles systems, associating the identified material, water and energy flows to their energy contents and carbon emissions. Then was investigated the possibility to reduce the footprints of water consumption, a question that was answered by the forecast of future drivers, technologies, and trends.Energy consumption throughout the urban water system is respectively of 116 and 311 kWh/cap.year in Nantes and Oslo. This is far from the total energy used directly and indirectly by individuals in France or Norway. However, such values are by no means unimportant, with 2.19 kWh/m3 final consumption in Nantes versus 1.83 in Oslo. A direct consequence to this opposition is thus that it becomes possible not stop at the total figures per capita and rather split it up, in order to aim for improvement, either on the requirement per unit volume, or on consumption trends. The carbon footprints associated to the consumption of water in Nantes and Oslo can also be viewed as not extremely high with regards to other services, with 25 kg CO2e/cap.year in Nantes and 45.5 kg CO2e/cap.year in Oslo. However, carbon impacts related to the amount of energy used are quite high: 215 g CO2e/kWh for the French utility and 145 g CO2e/kWh for the Norwegian one, equivalent to fossil fuel electricity mixes. Indeed, water cycles depend on indirect energy flows such as chemicals, which rely on fossil resources.The other outcome of this work is based on the water utilities’ role: not only to produce water but also to clean wastewater. Thanks to policies and technologies, they are able to recover the useful resources: carbon, nitrogen and phosphorus, and the choice of use of these elements can offset a part of the energy used and carbon emitted.Such an element has great importance. Scenarios show that in a few years, up to two thirds of the energy used by the utilities could be offset, and several times their emissions in carbon as well, if the by-products (biogas and sludge) are used properly. In order to make the change effective, the utilities have access to a span of different measures to create impacts. Anaerobic wastewater treatment associated to biogas use as bus fuel, sludge use as fertiliser, are direct ways to offset emissions. Decentralisation of the water supply and rainwater harvesting are also major policy measures that can be implemented to decrease the reliance of UWCS on external resource.
49

Residential building stocks and flows as dynamic systems : Chilean dwelling stock and energy modeling, including earthquakes.

Gallardo, Carla January 2012 (has links)
The building sector comprises a very important part of each country’s economy, playing an important role in the consumption of resources and energy. In practice there is little knowledge on how the building stock develops. It is useful then to understand the dynamics and the metabolism of the built environment. Research on building stocks, predominantly on the residential sector, has been performed mainly for developed countries. There is little or none research on building stock for developing countries, so given that there is still a big gap regarding service levels (floor area per capita) between developed and developing countries, it is of importance to understand the dynamics of developing countries as well.Given that earthquakes occur in populated areas, it is important to assess the dynamics of such systems. The Chilean dwelling stock is subjected to earthquakes, so this focused on including earthquake activity to the dynamic MFA model of the dwelling stock. A leaching approach was used, basing the analysis on the typology distribution of different vulnerability classes. Different scenarios were defined in order to analyze the effect of policies on building codes and practices on the typology distribution of the stock, and hence on the demolition and renovation rate due to earthquakes. Policies for strengthening and renovating the building stock have a large positive impact on overall demolition rates. Patching types of policies have little effect when it comes to making the stock less vulnerable in the long term.An energy analysis was carried out for the overall stock, based on the mass balance yielded by the building stock dynamic MFA model. Effects of policies on energy and renovation standards are observed through the analysis of scenarios as well. The energy consumption of the stock has not reached saturation yet, and the timing for this will be strongly influenced by the energy intensity development of the stock. The combined effect of policies for decreasing the vulnerability of the dwelling stock and energy efficiency policies could be further explored if each vulnerability class could be described by an energy intensity factor. Further data gathering or modeling on this would be of importance to further understand the system.Even if there is data uncertainty and the model present weaknesses, the approach used for modeling the Chilean dwelling stock allows for a systematic view of the effects earthquakes on the system. The building sector is an important contributor of CO2 emissions. A detailed carbon analysis for the future development of the building stock is then relevant to this study. However, considering the time constraints, this research has focused on the modeling of the building stock including earthquake activity and an overall energy assessment of it. A simplified carbon analysis was left out due to the fact that by considering a constant emission factor the analysis of the trends of CO2 emissions would be equivalent to the analysis of the energy model.
50

'Less is more' : Pathways for Lower Steel Stocks in Developing Countries : An assessment of leapfrogging potentials in transportation D1-2012-38

Broca, Mita January 2012 (has links)
Effective climate change mitigation requires global carbon emissions to be reduced at least by 50% over the 2000-2050 period, as recommended by the IPCC. Producing steel accounts for approximately 9% of all energy-related green house gas emissions. With the rapid urbanization and industrialization of the developing countries, demand for steel is anticipated to at least double by 2050. The daunting challenge is how emerging economies like India and China will be able to develop into modern economies without generating significant repercussions for the global climate. Today’s best available steel making processes have optimised energy use to a large extent. For further emission reduction, climate change mitigation policies primarily aim at a response based on carbon sequestration of process and electricity related emissions. However, these approaches are far from proven and carry both technical and financial risks. This research shifts the focus from supply-side to demand-side measures to address this issue. The need to include management of in-use stocks in environmental policy is underlined, as stocks are important drivers for resource and energy consumption as well as waste and emission generation. The central idea behind this work is to highlight that the goal for developing countries should not be to acquire the same level of in-use stock as seen in the developed counties, but to attain the same services enjoyed by them with lower material stocks. This study first attempts to quantify the differences in steel stocks in vehicles, along with the total embodied energy and emissions among a set of developed countries. Using a novel approach, service provided by the vehicle stock is defined using suitable parameters. Further, using passenger car steel stock as an example, scenarios are developed for India, which reflect ways in which India could possibly attain the same level of service as seen in industrialized countries, but with lower steel stock. The approach presented here is based on a static model, which is used to provide an indication of the embedded energy and emissions associated with the instantaneous build-up of the steel stock, to provide a certain level of service. Factors that influence dependence on personal transport are studied and possible ways of making people less reliant on cars are suggested. The results from the scenario analysis indicate that for passenger cars, the emissions embedded in steel stock can be reduced by 75% if India chooses not to replicate the US pattern of development, but instead, with proactive planning and decision making, adopt measures that can make the population less dependent on individual transport. This project therefore, is a step towards drawing attention to the importance of including the role of anthropogenic stocks in environmental policy.

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