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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.
81

A screening LCA on the recycling chlorinated pilgering oil

Spruijt, Yannick January 2018 (has links)
In the metalworking industry lubricants are used for   production. For production of seamless stainless steel pipes Sandvik   Materials Technology uses chlorinated pilgering oil, a lubricant produced   from paraffin and chlorine. Today these lubricants are disposed by   incineration when the lubricant is too contaminated so production drops, and   the lubricant is replaced by new lubricant. RecondOil found a solution to clean   these oils instead of disposing them. To assess the environmental impact for   the process of cleaning a screening Life Cycle Assessment (LCA) was   conducted. The functional unit used is the amount of chlorinated pilgering   oil used per year, and impact categories were chosen to be Global Warming   Potential (GWP) and Acidification Potential (AP). The study was conducted for   the impact from cradle to grave. The outcome of the LCA showed that the main   impact for GWP comes from the disposal phase for the conventional process,   which is incineration. For the cleaning and reusing process major impacts   where found to be from the transportation of raw materials, half-fabricates,   products and waste. It was found that only transportation had a major impact   on AP. The results show that for both GWP and AP the recycling process has   lower potential emissions than the conventional method, but further research   on for example electricity and chlorine production is needed to compose a   better comparison of the two processes from a life cycle perspective. / <p>2018-06-08</p>
82

Ett holistiskt synsätt vid husprojektering : En explorativ livscykelstudie av inbyggd och operationell energi för ett passivhus - vilka är energibovarna?

Lindgren, Jenny January 2018 (has links)
Ett holistiskt synsätt vid husprojektering. Det här examensarbetet presenterar en utforskande studie av den inbyggda- och operationella energin ur ett livscykelperspektiv hos ett passivhus. Där aspekter som påverkan från valet av isoleringsmaterial, miljöeffekter och geografisk placering behandlats. Med syftet att undersöka vilken procentuell variation av livscykelenergin för operationell- och inbyggd energi som sker när omgivningarna för ett passivhus ändras mellan Kiruna, Luleå och Malmö samt om isoleringsmaterialet ändras. Studien har begränsats till att undersöka den inbyggda energin hos isoleringsmaterialet som ingår i takkonstruktionen av passivhuset och miljöeffekter har bedömts utifrån energianvändning och CO2-utsläpp. Simulationer av den operationella energin utfördes för åtta olika uppsättningar av isoleringar i tre olika orter där en livslängd på 50 år antagits för huset. Två av isoleringarna hade en mycket högre energiförbrukning vid tillverkning och transport än de övriga. För de med lägre energibehov stod den inbyggda energin i isoleringsmaterialet för i Kiruna mellan 10-15 %, i Luleå mellan 15-20 % och i Malmö mellan 5-10 % av den totala livscykelenergin hos huset när den aktuella energimixen för uppvärmning användes vilket innebär att energibehovet beskrevs i primärenergiresurser tillverkade av icke förnyelsebara resurser. För de med högre energianvändning var samma förhållande mellan 25-35 %, 30-45 % och 20-30 %. Inget samband hittades mellan CO2-utsläpp för de olika undersökningarna och energibehovet vid tillverkning. Resultatet visar på en tydlig inverkan från den inbyggda energin för isoleringen på hela livscykelenergin därför dras slutsatsen att större hänsyn och ett helhetsperspektiv för miljöpåverkan från byggmaterialen bör tas då ett hus ska designas där all energiförbrukning för huset beskrivs i icke förnyelsebara energikällor. / A holistic approach on construction planning. This master thesis presents an exploratory study of the embodied- and operational energy of a passive house from a life cycle perspective. Where aspects such as the effect of insulation choice, environmental impacts and geographic location are treated. With the objective to investigate the variation of the life cycle energy for operational- and embodied energy when the surroundings for a passive house changes between Kiruna, Luleå and Malmö and the insulation material varies. The study is limited to examine the embodied energy of the insulation in the roof construction of a passive house. Environmental impacts have been assessed on the basis of energy consumption and carbon emissions. Simulations of operational energy was performed for eight different sets of insulation in three different places where a life span of 50 years was adopted for the house. Two of the insulations were found to have a much greater embodied energy than the other. For those insulations with lower energy the embodied energy was in Kiruna between 10-20 % in Luleå between 15-30 % and in Malmö between 5- 10% of the total life cycle energy for the house when the actual energy mix for heating was used, which means that the energy was described in primary energy made of non-renewable resources. For those with higher embodied energy the same ratio was between 35-55 %, 50-80 % and 25- 50 %. No correlation was found between carbon dioxide emissions and the embodied energy of the various studies. The result indicates a great impact of the insulation on the total life cycle energy it is therefore concluded that a better account for the environmental impact of building materials should be taken when a house is designed where all of the energy demands of the house are presented in nonrenewable energy resources.
83

Management podniku a environment / Management and environment

Novák, Martin Bc. January 2007 (has links)
Práce hodnotí možnosti, které mají firmy na českém trhu v oblasti ochrany životního prostředí. Je zaměřena především na dobrovolné nástroje, které mohou společnosti zavést nad rámec plnění legislativních norem. Mimo to vysvětluje proč firmy na českém trhu zavádějí normy řady ISO 14000, jejich spokojenost s nimi a problémy, se kterými se setkali při jejich implementaci.
84

Modelo dinâmico de inventário de ciclo de vida (ICV) de processo unitário discreto de manufatura: um estudo de caso com retificação cilíndrica externa / Dynamic life cycle inventory (LCI) model of discrete manufacturing unit process: a case study for external cylindrical grinding machine

Remo Augusto Padovezi Filleti 20 July 2015 (has links)
A Avaliação do Ciclo de Vida (ACV) se destaca como uma ferramenta de grande relevância na identificação dos impactos ambientais potenciais de um processo ou produto. Apesar disso, a ACV apresenta grandes limitações na avaliação de processos de manufatura discreta, devido à falta ou à incerteza nos dados adquiridos na fase de Inventário de Ciclo de Vida (ICV). O objetivo do presente trabalho foi propor e implementar um modelo dinâmico de execução da fase de ICV para uma unidade de processamento de manufatura discreta (ou processo unitário discreto de manufatura), com o intuito de reduzir as limitações referentes à falta e à incerteza dos dados de ICV. O modelo proposto baseou-se na metodologia Unit Process Life Cycle Inventory (UPLCI) e usou um sistema de monitoramento em tempo real compatível com o protocolo de comunicação MTConnect®. A implementação do modelo proposto foi feita em uma unidade de processamento de retificação cilíndrica externa, na qual os fluxos de energia elétrica, ar comprimido e emissão de ruído sonoro foram monitorados em tempo real. Além disso, seis modos de operação de corte foram definidos e testados. Três destes modos usaram rebolo de Al2O3 e trabalharam com taxas específicas de remoção (Q\'w) iguais a 10, 50 e 100 mm/mm3.min. Outros três modos de operação usaram rebolo de cBN e tiveram valores de Q\'w iguais a 50, 100 e 150 mm/mm3.min. Cada modo de operação de corte foi testado duas vezes, totalizando 12 testes. Cada teste consistia na remoção de 3000 mm3 de material de peças cilíndricas feitas com a liga de níquel e cromo, o Inconel 751. A partir dos dados encontrados na fase de ICV, um estudo de ACV com abordagem gate-to-gate foi realizado para a avaliação do desempenho ambiental dos seis modos de operação de corte. Além disso, itens de desempenho de produção (como tempo de processo, relação G, rugosidade e circularidade) também foram avaliados para os seis modos de operação de corte. Os dados obtidos na fase de ICV mostraram que os modos de operação com o rebolo de cBN apresentaram valores de potência até 30% superiores aos modos de operação com rebolo de Al2O3 com as mesmas taxas específicas de remoção (Q\'w). A avaliação de desempenho de produção mostrou grande superioridade do rebolo de cBN, que atingiu o menor de tempo de processo (com Q\'w = 150 mm/mm3.min), valores de relação G até 40 vezes superiores aos encontrados para o rebolo de Al2O3, além de maior estabilidade e resultados melhores nos quesitos de rugosidade e circularidade. Na avaliação de desempenho ambiental, o modo de operação com rebolo de cBN e Q\'w = 150 mm/mm3.min apresentou os melhores resultados em todos os indicadores de impactos ambientais avaliados. A partir da aplicação do modelo proposto pelo presente trabalho, foi possível criar um banco de dados de ICV organizado e em tempo real, fundamental para a realização das avaliações de desempenho ambiental e de produção. Além disso, foi possível determinar que o modo de operação com rebolo de cBN e Q\'w = 150 mm/mm3.min apresentou a melhor relação entre desempenho de produção e desempenho ambiental dentre os seis modos testados. / Life Cycle Assessment (LCA) is one of the most prominent tools to identify the potential environmental impacts of a process or product. The LCA, however, has great limitations on the assessment of discrete manufacturing processes, due the lack or the uncertainty of the data acquired during its Life Cycle Inventory phase (LCI). The objective of this work was to propose and to implement a dynamic model to perform the LCI phase for a discrete manufacturing unit process, in order to minimize the limitations associated with the lack and uncertainty of the LCI data. The proposed model was based on the Unit Process Life Cycle Inventory (UPLCI) methodology and used a real time MTConnect® compliant monitoring system. The implementation of the proposed model was executed on an external cylindrical grinding unit process, which had its energy, compressed air and noise emission flows monitored in a real time basis. Besides that, six cutting operational modes were defined and tested. Three of the cutting modes used a corundum grinding wheel and worked with specific removal rates Q\'w equals to 10, 50 and 100 mm/mm3.min. The other three modes used a cBN grinding wheel and worked with Q\'w equals to 50, 100 and 150 mm/mm3.min. Each cutting mode was tested twice, resulting in 12 tests. Each test consisted on the volume of removed material of 3000 mm3 from nickel-chrome alloy, the Inconel 751, cylindrical workpieces. From the LCI results, a LCA study was performed, using a gate-to-gate approach, to evaluate the environmental performance of the six cutting modes. Production performance items (process time, G-ratio, roughness and roundness) were also evaluated for the six cutting modes. The LCI data showed that the cBN wheel cutting modes presented power values 30% higher that the corundum wheel cutting modes with the same Q\'w specifications. The production performance evaluation showed the superiority of the cBN grinding wheel, which achieved the lowest process time (with Q\'w = 150 mm/mm3.min), presented G-ratio values 40 times higher than the corundum wheel cutting modes and higher stability and best results for roughness and roundness. On the environmental performance evaluation, the cutting mode using cBN grinding wheel and Q\'w = 150 mm/mm3.min presented the best results for all the potential environmental impacts indicators. From the application of the model proposed by this work, it was possible the creation of an organized and real time LCI database, used to perform both environmental and production performance evaluations. Besides, it was possible to decide that the cBN wheel cutting mode with Q\'w = 150 mm/mm3.min presented the best tradeoff between environmental and production performances among the six tested cutting modes.
85

Ferramenta para análise de desempenho ambiental na geração de energia elétrica / A tool for analysis of environmental performance in electricity generation

Flavio Augusto Barrella 29 August 2011 (has links)
A produção de energia elétrica é intimamente vinculada ao seu consumo. Ela acompanha o consumo, pois os processos de produção não armazenam energia e o ponto ótimo se dá quando não se tem nem excesso nem falta da quantidade de energia produzida em relação à consumida. Por sua vez, o consumo de energia elétrica está relacionado ao padrão de crescimento e desenvolvimento da nação. Inúmeras evidências, associando o consumo de energia elétrica ao produto interno bruto e outros índices de desenvolvimento, são encontrados na literatura, os quais mostram claramente esta justa correlação. Por outro lado, o total de energia elétrica produzida é o resultado da soma das produções individuais das diversas fontes de recursos, tais como: gás natural, carvão vapor, hídricas, produtos de cana, eólica e urânio. Este é um cenário típico de produtores e consumidores, em que os produtores concorrem, entre si, para suprir a demanda. Qualquer variação na produção de um é compensada pela produção dos outros, a fim de se manter a demanda atendida na exata medida de suas necessidades. Neste trabalho foram desenvolvidas uma metodologia original e uma ferramenta de simulação, no aplicativo MATLAB®, e estabelecidos parâmetros e indicadores ambientais para auxiliar a tomada de decisões quanto ao direcionamento de investimentos na área de produção de energia elétrica, mostrando como minimizar os efeitos nocivos ao meio ambiente e acompanhar o crescimento da demanda simultaneamente. São utilizadas técnicas e metodologias consagradas, tais como a Avaliação do Ciclo de Vida, a Contabilidade Emergética, a Análise Estatística, a Teoria de Sistemas sobre a base de dados oficial do governo brasileiro, isto é, a matriz 27x47 do relatório anual Boletim Energético Nacional (BEN) do Ministério das Minas e Energia (MME), fornecendo uma visão holística e otimizada do setor energético nacional e em particular da área de energia elétrica. Alguns temas polêmicos como o efeito da utilização da área florestal para a produção de energia elétrica e o esgotamento de reservas energéticas são discutidos no final deste trabalho. / The production of electricity is closely linked to its consumption. It follows the consumption, because the production processes do not stock up energy and the optimum point is when it does not have over or less quantity of energy produced according to its consumption. In turn, energy consumption is related to the level of growth and development of the nation. A lot of evidence associating energy consumption to gross domestic product and other development indicators are found in the literature, which clearly shows this correlation. On the other side, there are several sources of resources from which is produced electric power, such as: natural gas, steam coal, hydro, sugarcane waste, wind and uranium in amounts that together supply the need consumption required all the time and could supply more than the required amount. This presented scenario is a typical example of producers and consumers, where producers compete to supply demand, and any variation in one of them is offset by the production of others, in order to get demand attended in the exact extent of their needs. In this work were developed a methodology and a tool, and also parameters were set to help decision making regarding guidelines for investments in the production of electricity, directing to minimize harm to the environment and at the same time meet the growing of the demand. Techniques and traditional methods were used, such as Life Cycle Assessment, Emergy Accounting, Statistical Analysis, the System Theory on the official database of the Brazilian government, that is, the 27x47 matrix of the Annual Report National Energy Bulletin (BEN) of Ministry of Mines and Energy (MME), providing an holistic and optimized overview in the energy national sector and in particular the electric power sector. Some controversial issues as the effect of using the forest for the production of electricity and the depletion of energetic reserves are discussed at the end of this work.
86

Photovoltaic energy in Kuwait : a financial and environmental analysis

Alazemi, Fahad Kh. A. T. S. January 2017 (has links)
This research is concerned with the drivers to utilize Renewable Energy in Gulf Cooperation Council countries with a focus on Kuwait. Such countries show high rates of electricity subsidies with high rate of emissions. At present, there is a continuous need to build new power stations to increase the electrical capacities, in order to cover the high peak loads that occurs in summers to avoid blackouts. The aim of this research is to create a combination of approaches to assess the adoption (economic and environmental) of Photovoltaic for electricity generation in Kuwait, which can be used to assist policy makers to compare various energy mixes and hence determine whether their current and future strategies are appropriate. Kuwait is in this research representative of an exemplar of oil-based economy in Gulf Cooperation Council region since they share similar energy policies and geographic location. The research provides an insight into the adoption of renewables in the region and the impact that particular energy mixes may have. Nine future potential scenarios are created showing different levels of PV deployment within Kuwait. The combination of approaches in this research estimates the economic and environmental impacts using Levelized Cost of Electricity and Life Cycle Assessment respectively of differing RE mixes. The findings show that energy storage increases the cost of electricity and the emissions from the photovoltaic sector. However, for the energy mix (PV and conventional), assuming oil price greater than 10.1$/Bbl. (when no storage required) and 15.2$/Bbl. (when using storage), PV generally lowers the cost of electricity, CO2 and SO2 emissions. Whilst, human toxicity is increased when storage is used. Taking all these factors into account, PV deployment is generally beneficial. However, if different combinations of impacts are considered, environmental and economic impacts may take different patterns. This led to a multi-objective problem to be solved. Using Pareto Front analysis, scenarios without storage requirement (i.e. 13% or less of photovoltaic) are preferable if only cost and human toxicity are considered. The contribution to knowledge from this research is that the deployment of large scale PV technology is beneficial in Kuwait economically and environmentally at least until 30% of the maximum peak load of electricity. The results have implications for other GCC countries with similar geographical, political and energy drivers; the methodology used in this research would be appropriate for these contexts.
87

Integrated Life Cycle and Techno-economic Assessment of the Conversion of High Productivity, Low Lipid Algae to Renewable Fuels

De Mill, Chad R 01 May 2017 (has links)
The production of alternative transportation fuels is imperative to meet future energy demands without contributing to global climate change. Advances in alternative processing techniques that have emerged due to interest in microalgae as a feedstock have led to a variety of potential processing pathways for the production of bio-based fuels. A major hurdle in the algal production process is maintaining a fast and stable algae culture. Monocultures, developed for their high lipid content, suffer from low productivity, are susceptible to crashes and require a constant supply of carbon dioxide to maintain productivity. In an effort to circumvent these obstacles, algal turf scrubber systems (ATS) are now being targeted not only for water purification, but as a means of producing algae feedstocks for fuel conversion. The resulting algae are capable of being harvested at a much higher density, requiring less energy for dewatering purposes. ATS systems do present other drawbacks that downstream technologies need to account for to make this system a viable means for fuel conversion. While polyculture algae species display great growth characteristics, they contain high percentages of nitrogen containing proteins and low lipid content. If not removed this nitrogen pollutes any resulting biocrude making it unacceptable for diesel fuel blends. This study investigates a processing method which reduces the nitrogen content of the resulting fuel by fermenting both carbohydrates and proteins into intermediate compounds. By tuning the E. coli fermentation stain it is hoped that the process will yield higher value co-products than those investigated in this study. The research contained herein incorporates laboratory experimentation with engineering systems modeling to assess the economic feasibility and environmental impacts of generating biofuels from ATS cultivated algae. Results show a minimum fuel selling price of $5.93 per gasoline gallon equivalent and greenhouse gas emissions of -0.0185 kg CO2eq per MJ fuel. Discussion points include process optimization in terms of minimum fuel selling price and global warming potential.
88

Fönster - renovering eller byte : En miljö- och kostnadsanalys av alternativen

Wiese, Lukas January 2019 (has links)
This report examines different types of window renovation optionsfrom an environmental and economical standpoint, with the purpose towiden the decision basis of the housing cooperative Utsikten, which’sreal estate is the subject of investigation in this report, and toenable corresponding investigations of similar real estates throughthe creation of a simplified calculation tool. The investigatedscenarios in the report are, apart from the reference case, changingthe windows to three glass windows, installation of an internalinsulation window, and replacing the inner glass of the existingwindow to insulation glass.Two calculation models were constructed, one with energy data fromthe simulation program VIP-energy. The other, simplified version withenergy data calculated from the windows U-value. Environmental datawas collected for installation of the different scenarios, transport,and energy consumption. Economy data was collected for installation,maintenance, and energy prices. All data was put together in thecalculation models and the results got compared.The calculations show that changing the windows to three glasswindows is the most economical alternative. It’s also the mostenvironmentally friendly option when data for Uppsala’s districtheating is used. If data for “district heating with high proportionrenewable“ is used, installation of an internal insulation window isthe most environmentally friendly option. Uncertainties about theresults are discussed in the report.
89

Exergetic Life Cycle Assessment of Electrospun Polyvinylidene Fluoride Nanofibers

Abbasi, Salman Ali 29 October 2014 (has links)
Assessing the sustainability of nanomanufacturing products and processes has been difficult to achieve using conventional approaches mainly due to an inadequate inventory, large process-to-process variation, and a dearth of relevant toxicology data for nanomaterials. Since these issues are long term in nature, it is required to create hybrid methodologies that can work towards filling the existing gaps. Merging thermodynamic techniques such as the exergy analysis with environmental assessments can help make better, more informed choices while providing an opportunity for process improvement by enabling to correctly quantify efficiency loss through the waste stream, and by locating the exact areas for improvement. A preliminary technique that utilizes environmental assessment feedback during the process design along with an exergy analysis is presented. As a test case, an environmental assessment aided by an exergy analysis was carried out on the electrospinning process for producing polyvinylidene fluoride nanofibers. The areas of greatest concern, both from an environmental as well as a thermodynamic point of view, have been found to be the high energy consumption and the complete loss of solvent during the process of electrospinning. Interestingly, exergy consumption is significantly higher for fibers with a smaller (
90

Towards a Sustainable Built Environment : Case Silverdal

Myllynpää, Ninja, Oskarsson, Linda January 2009 (has links)
<p>This paper intends to give the reader a wider knowledge about sustainable construction by taking a closer look at what drivers and goals have been of most importance in Silverdal - a construction project with environmental commitment and focus on energy efficiency. The research is formed by using a compilation of variables, such as regulation, brand building and risk management, which serve as a base for the qualitative research of the case study. The empirical findings have been gathered by interviewing people responsible for the Silverdal project. These findings imply that compliance with regulations has become more important with time and that brand building can still have greater relevance than long-term commitment to environmental related risk management. Also, economic benefits seem to be the most desired ones at the expense of making a contribution to real sustainability.</p>

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