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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.
71

Life Cycle Costing - Systematisierung bestehender Studien

Höhne, Christoph 30 April 2010 (has links) (PDF)
Die vorliegende Arbeit untersucht Wesensmerkmale des Life Cycle Costing (LCC, dt. Lebenszykluskostenrechnung) und dessen Anwendung veröffentlicht in Fachzeitschriften. Aufgrund der langen Historie des LCC seit Beginn der 30er Jahre, gibt es zu dem Forschungsthema bereits eine Vielzahl theoretischer und empirischer Studien. Dennoch existiert bis heute keine einheitliche Definition oder ein standardisierter methodischer Rahmen. Das Ziel dieser Arbeit ist es, LCC zu charakterisieren und eine sinnvolle Methode für die Klassifizierung der vorhandenen Forschungsarbeiten zu identifizieren um methodische und inhaltliche Unterschiede darzustellen. Angewandt wird die Methodik des Literature Review, respektive einer Mischform explorativ-induktiver, qualitativer und quantitativer Inhaltsanalyse. Den Prozess der Charakterisierung und Systematisierung leiten folgende Fragestellungen: Was sind die Motivatoren der Anwendung von LCC in Firmen? Gibt es ein standardisiertes Konzept analog zur Ökobilanz (LCA)? Was sind die wesentlichen Vorteile von LCC? Was ist momentan unbefriedigend erforscht? Wo und in welcher Form wird LCC angewandt? Ergeben sich aus F-1 bis F-4 spezifische Anwendungsbereiche? Zu Beginn erfolgt im Sinne der Vision des Life Cycle Thinking eine Erörterung möglicher Motivationen einer Zuwendung zu LCC aus unternehmerischer Entscheidungsperspektive. Dem folgt eine umfangreiche Analyse und Diskussion der wesentlichen Charakterzüge. Ausgehend dieser Erkenntnis ist ein Analyseraster abgeleitet um die zu bewertenden Studien geeignet zu kategorisieren. Ein direktes Ergebnis stellt die Evaluierung von 34 Studien zu LCC dar. Als mittelbare Ergebnisse der Systematisierung gelten die Erkenntnisse zur Wahl einer optimierten Suchstrategie und die Schaffung eines Startpunkts für Forscher, die sich zukünftig mit Detailfragen des LCC beschäftigen.
72

Techno-economic and Environmental Assessments of Replacing Conventional Fossil Fuels: Oil Sands Industry Case Studies

McKellar, Jennifer Marie 20 March 2014 (has links)
Conventional fossil fuels are widely used, however there are growing concerns about the security of their supply, volatility in their prices and the environmental impacts of their extraction and use. The objective of this research is to investigate the potential for replacing conventional fuels in various applications, focusing on the Alberta oil sands industry. Such investigations require systems-level approaches able to handle multiple criteria, uncertainty, and the views of multiple stakeholders. To address this need, the following are developed: life cycle assessment (LCA) and life cycle costing models of polygeneration systems; a life cycle-based framework for multi-sectoral resource use decisions; and a method combining LCA and real options analyses to yield environmental and financial insights into projects. These tools are applied to options for utilizing oil sands outputs, both the petroleum resource (bitumen) and by-products of its processing (e.g., asphaltenes, coke), within the oil sands industry and across other sectors. For oil sands on-site use, multiple fuels are assessed for the polygeneration of electricity, steam and hydrogen, in terms of life cycle environmental and financial impacts; asphaltenes gasification with carbon capture and storage (CCS) is the most promising option, able to reduce greenhouse gas (GHG) emissions to 25% of those of current natural gas-based systems. Coke management options are assessed with the life cycle-based framework; the most promising options are identified as: Electricity generation in China through integrated gasification combined cycle; and, hydrogen production in Alberta, either for sale or use by the oil sands industry. Without CCS, these options have amortized project values ranging from $21 to $160/t coke. The application of the combined LCA and real options analyses method finds that uncertainty in natural gas and potential carbon prices over time significantly impacts decisions on coke management; the formulated decision tree identifies increases of 29% and 11% in the financial and GHG emissions performance, respectively, of the overall coke management project compared to pursuing the decision identified by the life cycle-based framework. While promising options for replacing conventional fossil fuels are identified through systems-level analyses, there are trade-offs to be made among the financial, risk and environmental criteria.
73

Techno-economic and Environmental Assessments of Replacing Conventional Fossil Fuels: Oil Sands Industry Case Studies

McKellar, Jennifer Marie 20 March 2014 (has links)
Conventional fossil fuels are widely used, however there are growing concerns about the security of their supply, volatility in their prices and the environmental impacts of their extraction and use. The objective of this research is to investigate the potential for replacing conventional fuels in various applications, focusing on the Alberta oil sands industry. Such investigations require systems-level approaches able to handle multiple criteria, uncertainty, and the views of multiple stakeholders. To address this need, the following are developed: life cycle assessment (LCA) and life cycle costing models of polygeneration systems; a life cycle-based framework for multi-sectoral resource use decisions; and a method combining LCA and real options analyses to yield environmental and financial insights into projects. These tools are applied to options for utilizing oil sands outputs, both the petroleum resource (bitumen) and by-products of its processing (e.g., asphaltenes, coke), within the oil sands industry and across other sectors. For oil sands on-site use, multiple fuels are assessed for the polygeneration of electricity, steam and hydrogen, in terms of life cycle environmental and financial impacts; asphaltenes gasification with carbon capture and storage (CCS) is the most promising option, able to reduce greenhouse gas (GHG) emissions to 25% of those of current natural gas-based systems. Coke management options are assessed with the life cycle-based framework; the most promising options are identified as: Electricity generation in China through integrated gasification combined cycle; and, hydrogen production in Alberta, either for sale or use by the oil sands industry. Without CCS, these options have amortized project values ranging from $21 to $160/t coke. The application of the combined LCA and real options analyses method finds that uncertainty in natural gas and potential carbon prices over time significantly impacts decisions on coke management; the formulated decision tree identifies increases of 29% and 11% in the financial and GHG emissions performance, respectively, of the overall coke management project compared to pursuing the decision identified by the life cycle-based framework. While promising options for replacing conventional fossil fuels are identified through systems-level analyses, there are trade-offs to be made among the financial, risk and environmental criteria.
74

Valuing ecosystem services - linking ecology and policy

Noring, Maria January 2014 (has links)
Ecosystem services constitute a precondition for human welfare and survival. This concept has also become increasingly popular among both scientists and policymakers. Several initiatives have been taken to identify and value ecosystem services. Several services are threatened, and it has been concluded that in order to better manage ecosystem services they need to be further investigated and valued. By measuring them using a common metric—monetary value—they can be more easily compared and included in decision-making tools. This thesis contributes to this goal by presenting values for several ecosystem services and also including them in decision-making tools. Starting with a discussion of the concept of ecosystem services, this thesis aims to present values for certain ecosystem services and to illustrate the use of these values in systems-analysis tools such as cost-benefit analyses (CBA) and a weighting set. Links between ecology, economics and policy are discussed within a broader framework of ecosystem services. Five papers are included, in which two contingent valuation studies (CV) have been used to find values for different ecosystem services. One valuation study is focused on the effects from tributyltin (TBT) in Swedish marine waters. In addition, a quantitative assessment framework has been developed in order to simplify analysis of environmental status, progress in environmental surveillance and the relevance of different measures. It is suggested that the framework should also be used when assessing the impacts of other substances affecting the environment. The second valuation study investigates the risk of an oil spill in northern Norway. The results have been included in two CBAs and a weighting set. The first CBA compares costs for remediation of polluted sediments, caused by TBT, with the benefits of reducing TBT levels. The second CBA compares costs and benefits for reducing the probability of an oil spill. The weighting set includes monetary values on a number of impact categories where marine toxicity is based on the valuation study on TBT.  One study also examines the inclusion of environmental costs in life cycle costing (LCC) in different sectors in Sweden. Results show that respondents consider ecosystem values to be important. The values of Swedish marine waters and coastal areas outside Lofoten-Vesterålen in Norway have been identified and quantified in terms of biodiversity, habitat, recreation and scenery. In the Norwegian case, an ongoing debate on the issue of oil and gas exploration has had an impact on the number of protest bids found in the study. Based on the cost and benefits of limiting impacts on ecosystem services derived from the valuation studies, CBAs show that the suggested measures are most likely beneficial for society, and the results contribute to policy recommendations. A weighting set has been updated with new values through value transfer. The weighting set is compatible with LCA. The final study shows that companies and public organisations use environmental costs (internal and external) in a limited manner. In this thesis the ecosystem service concept is used both as an introduction and a guiding thread for the reader, as a way to frame the studies undertaken. The concept of ecosystem services can be useful, as it emphasises the importance of the services to humans. By finding and presenting values of ecosystem services, such services are more easily incorporated into decision-making. / <p>QC 20141121</p>
75

Anwendung monetärer und nicht-monetärer Entscheidungsinstrumente am Beispiel von Investitionsentscheidungen der MAN Nutzfahrzeuge AG

Bergheim, Kirtan, Gerbaulet, Clemens, Graßhoff, Nico, Kittlaus, Barnabas, Klapper, Helge, Plischtil, Max, Rehm, Franziska, Scheel, Ramona, Kirsch, Arne 11 October 2011 (has links) (PDF)
In der vorliegenden Arbeit wird der Beschaffungsprozess der MAN Nutzfahrzeuge AG analysiert. Zu diesem Zweck werden drei verschiedene Methoden angewendet. Das Ziel besteht darin herauszufinden, inwieweit die Berücksichtigung ökologischer Aspekte den Entscheidungsprozess beeinflusst, sodass nachhaltige Beschaffung eine sinnvolle Option bieten kann. Dazu werden verschiedene Beschaffungsalternativen unter Verwendung der Ansätze zur Lebenszykluskostenrechnung, Ökobilanzierung und Hemmnisanalyse verglichen. Ziel ist es, Empfehlungen für zukünftige Investitionsentscheidungen abzuleiten. Die vorliegende Ausarbeitung zeigt, dass die Ausweitung der Investitionsbetrachtung auf den gesamten Lebenszyklus weit über konventionelle Ansätze hinaus gehen.
76

Evaluation of the sustainability of controlling diffuse water pollution in urban areas on a life cycle basis

Tomasini Montenegro, Claudia January 2013 (has links)
Diffuse water pollution in urban areas is growing due to polluted runoffs. Therefore, there is a need to treat this kind of pollution. Different structural treatment practices can be used for these purposes. However, little is known about their environmental, economic and social impacts. Therefore, the aim of this study has been to develop an integrated methodology for sustainability evaluation of structural treatment practices, considering environmental, economic and social aspects. Both environmental and economic evaluations have been carried out on a life cycle basis, using life cycle assessment and life cycle costing, respectively. For social evaluation, a number of social indicators, identified and developed in this research, have been used. The methodology has been applied to the case of the Magdalena river catchment in Mexico City. Three structural treatment practices have been analysed: bio-retention unit, infiltration trench and porous pavement. Based on the assumptions and the results from this work, the bio-retention unit appears to be environmentally the most sustainable option for treatment of diffuse water pollution. It is also the second-best option for social sustainability, slightly behind the porous pavement. However, if the costs of treatment are the priority, then the porous pavement would be the cheapest option. If all the sustainability aspects evaluated here are considered of equal importance, then the bio-retention unit is the most sustainable option. Therefore, trade-offs between the different sustainability aspects are important and should be considered carefully before any decisions are made on diffuse water pollution treatment. This also includes the trade-offs with the additional life cycle impacts generated by the treatment options compared to the impacts from the untreated runoff. The decisions can only be made by the appropriate stakeholders; however, some recommendations are given, based on the outcomes of this research.
77

Instrumentarium für die lebenszyklusorientierte Bewertung und Auswahl von Faser-Kunststoff-Verbund (FKV)-Technologien

Hertel, Andrea 24 July 2019 (has links)
Produkt- und Prozesstechnologien stellen für Unternehmen einen bedeutenden Erfolgsfaktor, da sie direkt oder indirekt in Produktbestandteile eingehen und damit Einfluss auf die – häufig mehrstufige – Herstellung, die Produktqualität und Produktmerkmale sowie auf die Nutzung und Nachsorge der Produkt(bestandteil)e haben und mit Nutzenpotentialen im Lebenszyklus der Produkte bzw. Produktbestandteile verbunden sind. Um ökonomisch sinnvolle Technologieentscheidungen zu treffen, müssen Unternehmen einerseits die Erfolgsbeiträge der Technologien bewerten. Andererseits sind mit Technologiesubstitutionen oftmals erhebliche Investitionen, Lebenszykluskosten sowie Umsetzungsrisiken verbunden. Daher besteht die aus wissenschaftlicher und praktischer Sicht hoch relevante Fragestellung, wie entwicklungsbegleitend eine gezielte lebenszyklusbezogene Bewertung von Technologien zur Herstellung von Faser-Kunststoff-Verbund (FKV)-Komponenten erfolgen kann. Dieser an der Schnittstelle zwischen Wirtschafts- und Ingenieurwissenschaften angesiedelten Fragestellung kommt auch deshalb eine hohe Bedeutung zu, weil die Bewertung solcher Technologien und die darauf basierende Auswahl der aus ökonomischer Sicht „richtigen“, d. h. über den gesamten Lebenszyklus einen maximalen monetären Erfolg generierenden, Technologie von Bedeutung für den Erfolg und die Akzeptanz von Innovationen im Bereich des Leichtbaus sind. Gegenstand der Arbeit ist die Entwicklung eines Instrumentariums, das die strukturierte Bewertung und Entscheidungsfindung unter Berücksichtigung der im jeweiligen Anwendungsfall relevanten Ziele, Alternativen, Einflussfaktoren und ihrer kurz-, mittel- und langfristigen, bei verschiedenen Akteuren in der Supply Chain auftretenden, monetären und nicht-monetären Wirkungen unterstützt. Als Grundlage für die Antizipation und Modellierung lebenszyklusbezogener Folgen von Technologiesubstitutionen werden Referenzmodelle zur Abbildung der Lebenszyklen, der lebenszyklusbezogenen Prozesse und technologieinduzierten Wirkungen, die in verschiedenen Lebenszyklusphasen der FKV-Komponenten und der (End-)Produkte auftreten, erarbeitet. Darauf aufbauend wird im Rahmen eines Vorgehensmodells aufgezeigt, wie die Bewertung von Technologien aus ökonomischer Sicht mithilfe von Technologiebezogenen Lebenszyklusrechnungen und unter Einbeziehung von Ansätzen zur Prognose lebenszyklusbezogener Zahlungswirkungen und zur Monetarisierung von technologiebezogenen Nutzeneffekten erfolgen kann. Hierfür ist der strukturierte Einsatz vielfältiger, aus verschiedenen Disziplinen stammenden Instrumente und Methodenbausteine notwendig. Schließlich wird das Instrumentarium auf die Supply Chain-Ebene angewendet und an einem Fallbeispiel demonstriert.:1 Einführung 1 1.1 Problemstellung 1 1.2 Zielsetzung und Aufbau 8 2 Charakterisierung des objektbezogenen Untersuchungsgegenstandes 11 2.1 Begriffliche Grundlagen 11 2.2 Charakterisierung und technologische Gestaltungsmöglichkeiten von FKV-Komponenten 17 2.2.1 Charakterisierung von FKV-Komponenten 17 2.2.2 Materielle Zusammensetzung und Eigenschaften von FKV-Komponenten 22 2.2.3 Fertigung von FKV-Komponenten 27 2.3 Entwicklungsbegleitende Auswahl von Fertigungstechnologien 35 2.4 Anforderungen an das Instrumentarium 51 3 Methodischer Bezugsrahmen – Ausgangssituation und Forschungsbedarf 57 3.1 Ausgewählte betriebswirtschaftliche Lebenszyklusmodelle 57 3.1.1 Einführung ─ Modellbegriff und Überblick 57 3.1.2 Allgemeine Lebenszyklusmodelle 61 3.1.3 Methodische Ausgestaltung spezifischer Lebenzyklusrechnungen 62 3.2 Verfahren der entwicklungsbegleitenden (Herstellkosten-)Kalkulation 69 3.3 Methoden zur lebenszyklusorientierten Produkt- und Prozessgestaltung 75 3.4 Zwischenfazit 90 4 Modellierung von Lebenszyklen, Prozessen und Wirkungen 93 4.1 Systemischer Komponenten- und Produktlebenszyklus 93 4.2 Lebenszyklusbezogene Prozessmodelle 98 4.2.1 Zur Bildung von Prozessmodellen 98 4.2.2 Generisches lebenszyklusbezogenes Prozessmodell 102 4.2.3 Prozessmodell für die Fertigung 108 4.2.4 Prozessmodell für Nutzung und Service 115 4.2.5 Prozessmodell für die Nachsorge 121 4.2.6 Nutzung von Prozessmodellen 127 4.3 Strukturierung lebenszyklusbezogener Wirkungen 130 5 Vorgehensmodell – Konzeption, Ausgestaltung und Fallbeispiel 136 5.1 Vorstellung und Einsatzbereich 136 5.2 Definition von Systemgrenzen 143 5.2.1 Charakterisierung 143 5.2.2 Instrumente 144 5.3 Festlegung von lebenszyklusbezogenen Zielgrößen 148 5.3.1 Charakterisierung 148 5.3.2 Instrumente 154 5.4 Generieren und Modellieren von Technologiealternativen 159 5.4.1 Charakterisierung 159 5.4.2 Instrumente 161 5.5 Identifizierung, Analyse und Prognose relevanter Einflussfaktoren 163 5.5.1 Charakterisierung 163 5.5.2 Instrumente 165 5.6 Ermittlung der Werte der Zielgrößen(elemente) 169 5.6.1 Charakterisierung 169 5.6.2 Instrumente 173 5.7 Entscheidungsfindung 188 5.7.1 Charakterisierung 188 5.7.2 Instrumente 189 5.8 Anwendung auf / Erweiterung um die SC-Ebene 192 5.9 Fallbeispiel 206 5.9.1 Problembeschreibung 206 5.9.2 Vorgehensmodellbasierte Bewertung und Auswahl der Technologiealternativen 207 6 Zusammenfassung und Ausblick 224
78

An Environmental (LCA) and economic assessment (LCC) of on-farm and centralized alternatives for biogas production for two Swedish farms in Götene

Ouakrim, Abdelali January 2023 (has links)
Biogas production through anaerobic digestion is an important part towards the achievement of a bio-based and circular economy in Sweden. In fact, Swedish government proposed a strategy suggesting that biogas production should be increased from 2 TWh today to 7 TWh by 2030. Sweden has a large potential for biogas production from agricultural residues, not the least the Region Västra Götaland (RVG) where the stakeholders from the present study are located. The study explores the possibilities to use farm manure in co-digestion with deep bedding to produce biogas. The possibilities include two main alternatives for biogas production; mainly combined heat and power (CHP) to produce heat and electricity and biogas upgrading to produce bio-methane. The study took two existing organic farms in the municipality of Götene as a case study as well as an under-construction biogas plant by the company Gasum. The results of the present study also confirm that biogas could be a better option both economically and environmentally than fossil fuels. Additional results show that diesel consumption and energy prices are seen as hotspots that greatly influence both technical performance and economic profitability of biogas production. Another parameter is the geographical location of the studied system which could delimit or enhance the biogas production prospects depending on the proximity to gas grid or biogas unit. The aim of the study is to assess which of the studied alternatives is most profitable and has less environmental impacts; sending liquid manure to a biogas plant and receiving liquid fertilizer in exchange (centralized scenario) or invest in a biogas plant at the farm (on-farm scenario). A life cycle assessment (LCA) was conducted to compare environmental impacts of producing the equivalent of 1 MWh of biogas through on-farm plant and a biogas unit operated by the Finnish company Gasum. While a life cycle costing (LCC) was carried out considering a 10 year period with a 3% interest rate to analyze which of the two aforementioned options is more profitable for both farmers. Further this study aims to spur the interest of other scholars to further explore the potential of biogas/biomethane production within the agriculture sector and provide a better understanding of the different dynamics that impact the balance between energy provisions and the farm production process, and thus assist farmers to take part in the transition to a more renewable energy source.
79

Life Cycle Assessment and Costing of Geosynthetics Versus Earthen Materials

Chulski, Katherine D. January 2015 (has links)
No description available.
80

Transition to a Sustainable Circular Furniture Economy : Integrated environmental and economic impact assessment of circular changes

Führer, Sophie January 2021 (has links)
The circular economy is presented as a solution to reconcile environmental protection with economic endeavours. However, only 9% of the global manufacturing currently deploys circularity. Within the furniture industry, with its intensive use of resources, the adoption remains limited. However, the application of furniture remanufacturing practices in Europe is currently estimated to be a €300M turnover while presumably avoiding around 3.3 to 5.7 Mt CO2 eq. The literature on the transition to circular furniture has not yet identified the success factors and practical insights to facilitate the adoption of circularity. Therefore, this research sets out to evaluate the economic and environmental benefit that could be achieved by transitioning from a business-as-usual furniture product to a circular one. The analysis is conducted in cooperation with two European companies – a circular kitchen start-up and a traditional public seating retailer. A cradle-to-grave life cycle costing and life cycle assessment investigates the two case studies regarding their change trajectories for their costs and environmental impacts. With its novel design and changed material composition, the circular kitchen reduced the global warming potential of a standard kitchen by about 40%, which comes at a cost premium of 5%. Likewise, the circular transformation in the second case indicated similar environmental impact changes and economic benefit compared to the conventional product. The total life cycle costs decreased by 10%, while the results reveal a coincidental lowered global warming potential by one fourth. The integrated assessment also reveals the pre-production and production phase for both case studies as the most impactful even after the application of circular strategies. The outcomes coupled with the qualitative assessment further demonstrated decisive internal and external factors accompanying the successful transition of the furniture companies. Still, a vast amount of similar case studies is necessary to validate the change trajectories to facilitate the industry-wide adoption of circular strategies, as discussed in the present study. / Den cirkulära ekonomin presenteras som en lösning för att förena miljöskydd med ekonomiska mål. Dock använder endast 9% av den globala tillverkningen cirkuläritet i dagsläget. Inom möbelindustrin, med sin intensiva resursanvändning, är cirkuläritet fortfarande begränsat. Samtidigt uppskattas återtillverkning av möbler i Europa omsätta 300 miljoner euro och undvika omkring 3,3 till 5,7 miljoner ton koldioxidekvivalenter.  Litteraturen om övergången till cirkulära möbler har ännu inte identifierat några framgångsfaktorer eller praktiska insikter för att underlätta övergången till cirkuläritet. Denna studie ämnar därför att utvärdera de ekonomiska och miljömässiga fördelar som skulle kunna uppnås genom att övergå från en möbelprodukt som är business-as-usual till en cirkulär produkt. Analysen görs i samarbete med två europeiska företag – en cirkulär köks-startup och en traditionell återförsäljare av möbler för offentliga rum och ytor. Genom livscykelkostnads- och livscykelanalys undersöktes de två fallstudierna.  Med sin nya design och förändrade materialkomposition minskade det cirkulära köket den globala uppvärmningspotentialen i ett standardkök med cirka 40%, vilket skedde till en kostnadspremie på 5%. På samma sätt visade den cirkulära omvandlingen i det andra fallet liknande miljökonsekvensförändringar och ekonomiska fördelar jämfört med den konventionella produkten. De totala livscykelkostnaderna minskade med 10%, medan även potentiell klimatpåverkan minskade med en fjärdedel. Den integrerade bedömningen visar också att förproduktions- och produktionsfasen för båda fallstudierna är de faserna med mest signifikant påverkan, även efter tillämpningen av cirkulära strategier.  Resultatet demonstrerar tydliga interna och externa faktorer som medföljer en framgångsrik övergång för möbelbolag. En stor mängd liknande fallstudier är dock nödvändiga för att validera de kvantitativa fynden och facilitera bredare applicering av cirkulära strategier inom sektorn.

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