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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Life cycle assessment of bridges, model development and case studies

Du, Guangli January 2015 (has links)
In recent decades, the environmental issues from the construction sector have attracted increasing attention from both the public and authorities. Notably, the bridge construction is responsible for considerable amount of energy and raw material consumptions. However, the current bridges are still mainly designed from the economic, technical, and safety perspective, while considerations of their environmental performance are rarely integrated into the decision making process. Life Cycle Assessment (LCA) is a comprehensive, standardized and internationally recognized approach for quantifying all emissions, resource consumption and related environmental and health impacts linked to a service, asset or product. LCA has the potential to provide reliable environmental profiles of the bridges, and thus help the decision-makers to select the most environmentally optimal designs. However, due to the complexity of the environmental problems and the diversity of bridge structures, robust environmental evaluation of bridges is far from straightforward. The LCA has rarely been studied on bridges till now. The overall aim of this research is to implement LCA on bridge, thus eventually integrate it into the decision-making process to mitigate the environmental burden at an early stage. Specific objectives are to: i) provide up-to-date knowledge to practitioners; ii) identify associated obstacles and clarify key operational issues; iii) establish a holistic framework and develop computational tool for bridge LCA; and iv) explore the feasibility of combining LCA with life cycle cost (LCC). The developed tool (called GreenBridge) enables the simultaneous comparison and analysis of 10 feasible bridges at any detail level, and the framework has been utilized on real cases in Sweden. The studied bridge types include: railway bridge with ballast or fix-slab track, road bridges of steel box-girder composite bridge, steel I-girder composite bridge, post tensioned concrete box-girder bridge, balanced cantilever concrete box-girder bridge, steel-soil composite bridge and concrete slab-frame bridge. The assessments are detailed from cradle to grave phases, covering thousands of types of substances in the output, diverse mid-point environmental indicators, the Cumulative Energy Demand (CED) and monetary value weighting. Some analyses also investigated the impact from on-site construction scenarios, which have been overlooked in the current state-of-the-art. The study identifies the major structural and life-cycle scenario contributors to the selected impact categories, and reveals the effects of varying the monetary weighting system, the steel recycling rate and the material types. The result shows that the environmental performance can be highly influenced by the choice of bridge design. The optimal solution is found to be governed by several variables. The analyses also imply that the selected indicators, structural components and life-cycle scenarios must be clearly specified to be applicable in a transparent procurement. This work may provide important references for evaluating similar bridge cases, and identification of the main sources of environmental burden. The outcome of this research may serve as recommendation for decision-makers to select the most LCA-feasible proposal and minimize environmental burdens. / <p>QC 20150311</p>
2

Life Cycle Impacts of Road Infrastructure : Assessment of energy use and greenhouse gas emissions

Miliutenko, Sofiia January 2012 (has links)
Road infrastructure is essential in the development of human society, but has both negative and positive impacts. Large amounts of money and natural resources are spent each year on its construction, operation and maintenance. Obviously, there is potentially significantenvironmental impact associated with these activities. Thus the need for integration of life cycle environmental impacts of road infrastructure into transport planning is currently being widely recognised on international and national level. However certain issues, such as energy use and greenhouse gas (GHG) emissions from the construction, maintenance and operation of road infrastructure, are rarely considered during the current transport planning process in Sweden and most other countries.This thesis examined energy use and GHG emissions for the whole life cycle (construction, operation, maintenance and end-of-life) of road infrastructure, with the aim of improving transport planning on both strategic and project level. Life Cycle Assessment (LCA) was applied to two selected case studies: LCA of a road tunnel and LCA of three methods for asphalt recycling and reuse: hot in-plant, hot in-place and reuse as unbound material. The impact categories selected for analysis were Cumulative Energy Demand (CED) and Global Warming Potential (GWP). Other methods used in the research included interviews and a literature review.The results of the first case study indicated that the operational phase of the tunnel contributed the highest share of CED and GWP throughout the tunnel’s life cycle. Construction of concrete tunnels had much higher CED and GWP per lane-metre than construction of rocktunnels. The results of the second case study showed that hot in-place recycling of asphalt gave slightly more net savings of GWP and CED than hot in-plant recycling. Asphalt reuse was less environmentally beneficial than either of these alternatives, resulting in no net savings of GWP and minor net savings of CED. Main sources of data uncertainty identified in the two case-studies included prediction of future electricity mix and inventory data for asphalt concrete.This thesis contributes to methodological development which will be useful to future infrastructure LCAs in terms of inventory data collection. It presents estimated amounts of energy use and GHG emissions associated with road infrastructure, on the example of roadtunnel and asphalt recycling. Operation of road infrastructure and production of construction materials are identified as the main priorities for decreasing GHG emissions and energy use during the life cycle of road infrastructure. It was concluded that the potential exists for significant decreases in GHG emissions and energy use associated with the road transport system if the entire life cycle of road infrastructure is taken into consideration from the very start of the policy-making process. / QC 20120229
3

A comparative Life Cycle Analysis of new and old designs of crane truck frames : Case study at Vemservice

Khan, Mahmudur Aryan January 2018 (has links)
The main objective of this Bachelor’s thesis is to investigate and deliver the results of environmental impacts of two different designs of crane truck frames. The aim is to investigate if additional new design of crane truck frames, with less energy and transportation during manufacturing of the crane truck, can improve energy efficiency of crane trucks throughout their lifecycle. Case study object for this report is Vemservice in Vemdalen, Sweden. As basis for the report the The Life Cycle Analysis ISO 14040 and ISO 14044 are used in this report in order to evaluate and compare the environmental impacts related to the lifecycle of new and old designs of 92 tonmeter crane truck frames from cradle to grave. The data was mainly collected and calculated by using the SimaPro software 8.0.5 which is based on the Ecoinvent 3 database. This study mainly analyzes environmental impacts such as GWP (Global Warming Potential), CED (Cumulative Energy Demand) and ReCiPe environmental impacts. The results showed that although new design frame has less transportation and energy demand during the manufacturing phase of the crane truck, the overall life cycle of the new design crane truck frame has higher environmental impacts than the existing old design of the crane truck frame. This is due to that the new design frame is 213kg heavier than the old design frame, which the crane truck is carrying during its using period. This study also investigated whether the new design frame, with stronger steel (Ecoupgraded steel) and a reduction of 15% of the total weight of frame, has a lower environmental impact in the life cycle of the EcoUpgraded steel frame compared to the current new design and old design frames life cycle. / <p>2018-06-29</p>
4

Comparative analysis of linear and circular manufacturing system paradigms for a steel-based product. : A case study of a mailbox manufacturing company

ALAGBADA, SAMUEL January 2022 (has links)
The manufacturing industry has exerted a tremendous impact on the natural environment. The aim of this thesis is to evaluate the consequences of shift from linear manufacturing system to circular manufacturing system in order to decouple the environmental burden of production and consumption process in relation to quantity of carbon footprint, cumulative energy demand, natural resource consumption, waste generated and recovered presently. In response to this, life cycle assessment (LCA) is used to quantify and compare the associated environmental impact of the current manufacturing system of both Linear manufacturing system and the circular manufacturing system. The thesis therefore asserts that circular manufacturing system (CMS) is more sustainable compared to linear manufacturing system (LMS) in relation to its reduction capacity of the prevailing environmental indicators most especially global threat of natural resources depletion and climate change confronting biodiversity. The result shown that CMS seems more sustainable compared to LMS in relation to the studied environmental indicators. Further to this, the emerging circular manufacturing system, its transitional shift, challenges, and its relationships with other manufacturing dynamics for consideration are also highlighted and discussed. It was concluded that these prominent challenges are caused by organizational management in relation to leadership and communication (OLC), has the highest impact value. Similarly, the consequential effect was seen on the level of implementation of government policy (GPI) and deployment of state of the art design, knowledge and technology (DTK) for the paradigm shift. So, it is suggested that OLC should be given due consideration.
5

Análise ambiental, energética e econômica de arranjo processual para reúso de água em refinaria de petróleo. / Environmental, energetic and economic analysis of a process design for water reuse in petroleum refinery.

Gripp, Victor Sette 18 December 2013 (has links)
Foi construído um modelo representativo do ciclo de vida da água em uma refinaria de petróleo, contemplando todos os usos a que esta se presta. Nesse contexto foram avaliados do ponto de vista ambiental, energético e econômico cenários em que etapas adicionais eram incorporadas ao tratamento de efluentes de forma a viabilizar o reúso de água e o fechamento do circuito na própria refinaria, reduzindo assim a necessidade de captação e, consequentemente, de tratamento da água bruta captada pela refinaria. O Cenário I corresponde ao cenário-base, sem implantação de nenhuma ação voltada ao reúso. No Cenário II, é incorporada a etapa adicional chamada Tratamento Fase 1, constituída por um processo de Clarificação seguido de uma Eletrodiálise Reversa (EDR) que permite o reúso de 255,7 m3/h dos 350 m3/h lançados inicialmente ao corpo hídrico no Cenário I. No Cenário III, é incorporada ao arranjo do Cenário II uma etapa de Cristalização Evaporativa para tratar o concentrado salino da EDR, recuperando, assim, mais 55,4 m3/h dos 350 m3/h lançados inicialmente, utilizando, para isso, vapor residual inicialmente não aproveitado pela refinaria. A análise ambiental foi desenvolvida por Avaliação do Ciclo de Vida (ACV) e constatou um desempenho muito semelhante dos três cenários. Apesar disso, a análise em perfil aberto, de impactos de midpoint, evidenciou ganhos ambientais significativos associados ao fechamento de circuito de água e, embora com vantagens muito discretas, o Cenário III apresentou um desempenho superior ao do Cenário II em todas as categorias e, na grande maioria delas, também superior ao desempenho do Cenário I. A análise de indicador único, em endpoint, destacou o impacto em Mudança Climática, relativo principalmente à queima de gás natural na caldeira para a geração de vapor, como o principal impacto ambiental associado ao ciclo de vida da água na refinaria, responsável por mais de 90% do valor correspondente ao resultado do indicador único. A análise energética foi desenvolvida utilizando-se o indicador de Demanda Cumulativa de Energia (CED) e resultou em um desempenho superior do Cenário I, ainda que com pequenas diferenças em relação aos Cenários II e III. O pior desempenho foi o do Cenário II. Comparando-se a contribuição relativa dos diferentes tipos de energia, destaca-se a energia de origem hidrelétrica, responsável por cerca de 80% do indicador único de CED em todos os três cenários. A análise econômica foi realizada por meio de indicadores tradicionalmente utilizados para a análise de viabilidade de projetos Taxa Interna de Retorno (TIR) e Valor Presente Líquido (VPL) , considerando, como referência, as regras de cobrança pelo uso da água vigentes na bacia do rio Paraíba do Sul. Com os preços cobrados atualmente pelo uso da água desta bacia, a implantação de ambos os cenários de reúso (II e III) não se viabiliza economicamente. Para que isso ocorra, o valor cobrado pelo uso da água teria que ser da ordem de 50 a 80 vezes maior do que o que é cobrado atualmente. Dentre os cenários de reúso, o Cenário II apresentou desempenho econômico superior ao do Cenário III. / It was built a representative model of the water life cycle within a petroleum refinery, considering all the uses in which it is applied. In this context, under environmental, energetic and economic perspective, different scenarios were analyzed, where further treatment stages were added to the wastewater treatment process so that recycled water could be provided back to the refining process, reducing, therefore, the need for freshwater intake and pretreatment by the refinery. Scenario I is the base scenario, without implementation of any water reuse aimed action. In Scenario II, it is incorporated the additional stage called Phase 1 Treatment, which consists of a Clarification process followed by an Electrodialysis Reversal (EDR).This enables the recycling of 255.7 m3/h from the 350 m3/h previously discharged to the water body in Scenario I. In Scenario III, it is incorporated to the Scenario II setting an Evaporative Crystallization process for treating the concentrated brine resulting from the EDR process. This enables the recovery of more 55.4 m3/h from the 350 m3/h initially released, using, for that, the energy from residual steam previously not used by the refinery. The environmental analysis was developed through Life Cycle Assessment (LCA) and found very similar performances for all three scenarios. Despite that, the open profile analysis, of midpoint impacts, showed significant environmental gains from the closure of the water circuit and, though with very small advantages, Scenario III showed a better performance than Scenario II in all impact categories and, in most of them, also better than Scenario I performance. The single score analysis, considering endpoint impact categories, highlighted Climate Change, specially related to the natural gas burning in the boiler for steam generation, as the main impact category associated to the water life cycle within the refinery, being responsible for more than 90% of all the value of the single score indicator. The energetic analysis was developed using the Cumulative Energy Demand (CED) indicator and resulted in a better performance of Scenario I, even if with just small differences from Scenarios II and III. The worst performance was from Scenario II. Comparing the relative contribution of the different types of energy, the hydroelectricity was the most important one, being responsible for around 80% of the CED single score in all three scenarios. The economic analysis was developed through traditional indicators used for assessing projects viability Internal Return Rate (IRR) and Net Present Value (NPV), considering, as reference, the rules of charging for water use valid nowadays at the Paraíba do Sul river basin. With the prices charged nowadays for the water use from this basin, the implementation of both reuse scenarios is not economic viable. In order to make it viable, the charged value would have to be around 50 to 80 times higher than it is today. Among the reuse scenarios, Scenario II had a better economic performance than Scenario III.
6

Energy efficiency in dairy cattle farming and related feed production in Iran

Maysami, Mohammadali 24 March 2014 (has links)
Umfang und Intensität der Milchviehhaltung nehmen immer weiter zu, dies gilt auch für den Iran. Das Ziel dieser Studie waren die Ermittlung und Bewertung der Energieeffizienz der Milchviehhaltung und Futterproduktion im nordwestlichen Iran. Daten wurden auf einem Futterbaubetrieb und auf 24 Milchviehbetrieben im nordwestlichen Iran erfasst. Es wurde eine Untersuchungsmethode erarbeitet, die auf der VDI-Richtlinie 4600 Kumulierter Energieaufwand (KEA) und dem ISO-Standard 14044 Umweltmanagement – Ökobilanz basiert. Die Energieintensität (EI) im Futter (in MJ kg-1 DM) lag bei 2,92 für Luzerne, bei 6,76 für Gerste, bei 9,19 für Mais, bei 12,36 für Raps, bei 2,45 für Frühjahrsmaissilage, bei 4,45 für Sommermaissilage und bei 4,35 für Weizen. Die EI der energiekorrigierten Milch (ECM) lag bei 5,84±0,69 MJ kg-1, bei einer Milchleistung von 6.585±1.221 kg ECM Kuh-1 Jahr-1. Die Futter waren die Hauptquelle des Energie-Inputs in die Milchproduktion, mit einem Anteil von 79%. Innerhalb der in den untersuchten Betrieben vorgefundenen Milchleistung (3.860-8.320 kg ECM Kuh-1 Jahr-1) verringerte sich die EI bei steigender Milchleistung (-0,36 MJ kg-1 ECM je +1.000 kg ECM Kuh-1 Jahr-1). Die Allokation des Energie-Inputs führte zu einem Anteil von 83% auf dem Milch, 2% auf den Fleisch und 15 % auf den Wirtschaftsdünger. Die EI des mit Bullen bis zu einer Körpermasse von 400 kg produzierten Schlachtfleisches lag bei 75,4±9,1 MJ kg-1, bei Fortführung der Mast bis zu 700 kg lag sie bei 103,8±11,4 MJ kg-1. Die EI bei ersetzten, geschlachteten Milchkühen bei 16,3 MJ kg-1 Fleisch lag. Die Kalkulation der EI auf Basis des Brennwert der Futter, führte zu einer EI in der Milchproduktion von 23,7±3,37 MJ kg-1 ECM und in der Erzeugung von Bullenfleisch (400 kg Körpermasse) 314±25 MJ kg-1. Das Energie Output-Input-Verhältnis (OIR) lag zwischen 2,03 MJ MJ-1 für Körnermais und 7,75 MJ MJ-1 für Frühjahrsmaissilage. Während OIR in der Milch 0,55 MJ MJ-1 und in der Fleisch 0,12 MJ MJ-1 betrug. / Dairy farming is increasing and becoming more intensive, attendant on higher energy inputs, also in Iran. The aim of this study was to estimate and assess the energy efficiency of dairy farming and the related feed production in north-western Iran. Data were gained from a com-pany producing feeds in north-western Iran, and from 24 dairy farms, also in north-western Iran for a period of three years. A method of investigation was devised based on the cumula-tive energy demand (CED) method introduced by VDI guideline 4600 and ISO standard 14044, which is used in life cycle assessment (LCA). The energy intensity (EI) in the feed production (in MJ kg-1 DM) was 2.92 for alfalfa, 6.76 for barley grain, 9.19 for maize corn, 12.36 for rapeseed, 2.45 for spring maize silage, 4.45 for summer maize silage and 4.35 for wheat grain. The EI for the energy corrected milk (ECM) was 5.84±0.69 MJ kg-1 with a ECM yield of 6,585±1,221 kg cow-1 yr-1. Feedstuff was the main source of energy input in milk production, with approximately 79% of the total energy input. The EI was decreasing with an increasing milk yield (-0.36 MJ kg-1 ECM per +1,000 kg ECM cow-1 yr-1), within the range of the milk yield found in the investigated farms (3,860-8,320 kg ECM cow-1 yr-1). The energy input was allocated to milk (83%), manure (15%) and meat (2%). The EI for boneless meat produced by bulls up to 400 kg body mass was 75.4±9.1 MJ kg-1 and produced by bulls up to 700 kg was 103.8±11.4 MJ kg-1. The allocated EI for meat of the replacing slaughtered cows was 16.3 MJ kg-1 of meat. By calculating the EI for milk production on the basis of the higher heating value (HHV) of feeds, it yielded in a mean EI of 23.7±3.37 MJ kg-1 ECM and an EI of 314±25 MJ kg-1 bull meat (400 kg body mass). Energy output input ratio (OIR) ranged between 2.03 MJ MJ-1 for maize corn and 7.75 MJ MJ-1 for spring maize silage production. While, in milk production OIR was 0.55 MJ MJ-1 and in meat production 0.12 MJ MJ-1.
7

Análise ambiental, energética e econômica de arranjo processual para reúso de água em refinaria de petróleo. / Environmental, energetic and economic analysis of a process design for water reuse in petroleum refinery.

Victor Sette Gripp 18 December 2013 (has links)
Foi construído um modelo representativo do ciclo de vida da água em uma refinaria de petróleo, contemplando todos os usos a que esta se presta. Nesse contexto foram avaliados do ponto de vista ambiental, energético e econômico cenários em que etapas adicionais eram incorporadas ao tratamento de efluentes de forma a viabilizar o reúso de água e o fechamento do circuito na própria refinaria, reduzindo assim a necessidade de captação e, consequentemente, de tratamento da água bruta captada pela refinaria. O Cenário I corresponde ao cenário-base, sem implantação de nenhuma ação voltada ao reúso. No Cenário II, é incorporada a etapa adicional chamada Tratamento Fase 1, constituída por um processo de Clarificação seguido de uma Eletrodiálise Reversa (EDR) que permite o reúso de 255,7 m3/h dos 350 m3/h lançados inicialmente ao corpo hídrico no Cenário I. No Cenário III, é incorporada ao arranjo do Cenário II uma etapa de Cristalização Evaporativa para tratar o concentrado salino da EDR, recuperando, assim, mais 55,4 m3/h dos 350 m3/h lançados inicialmente, utilizando, para isso, vapor residual inicialmente não aproveitado pela refinaria. A análise ambiental foi desenvolvida por Avaliação do Ciclo de Vida (ACV) e constatou um desempenho muito semelhante dos três cenários. Apesar disso, a análise em perfil aberto, de impactos de midpoint, evidenciou ganhos ambientais significativos associados ao fechamento de circuito de água e, embora com vantagens muito discretas, o Cenário III apresentou um desempenho superior ao do Cenário II em todas as categorias e, na grande maioria delas, também superior ao desempenho do Cenário I. A análise de indicador único, em endpoint, destacou o impacto em Mudança Climática, relativo principalmente à queima de gás natural na caldeira para a geração de vapor, como o principal impacto ambiental associado ao ciclo de vida da água na refinaria, responsável por mais de 90% do valor correspondente ao resultado do indicador único. A análise energética foi desenvolvida utilizando-se o indicador de Demanda Cumulativa de Energia (CED) e resultou em um desempenho superior do Cenário I, ainda que com pequenas diferenças em relação aos Cenários II e III. O pior desempenho foi o do Cenário II. Comparando-se a contribuição relativa dos diferentes tipos de energia, destaca-se a energia de origem hidrelétrica, responsável por cerca de 80% do indicador único de CED em todos os três cenários. A análise econômica foi realizada por meio de indicadores tradicionalmente utilizados para a análise de viabilidade de projetos Taxa Interna de Retorno (TIR) e Valor Presente Líquido (VPL) , considerando, como referência, as regras de cobrança pelo uso da água vigentes na bacia do rio Paraíba do Sul. Com os preços cobrados atualmente pelo uso da água desta bacia, a implantação de ambos os cenários de reúso (II e III) não se viabiliza economicamente. Para que isso ocorra, o valor cobrado pelo uso da água teria que ser da ordem de 50 a 80 vezes maior do que o que é cobrado atualmente. Dentre os cenários de reúso, o Cenário II apresentou desempenho econômico superior ao do Cenário III. / It was built a representative model of the water life cycle within a petroleum refinery, considering all the uses in which it is applied. In this context, under environmental, energetic and economic perspective, different scenarios were analyzed, where further treatment stages were added to the wastewater treatment process so that recycled water could be provided back to the refining process, reducing, therefore, the need for freshwater intake and pretreatment by the refinery. Scenario I is the base scenario, without implementation of any water reuse aimed action. In Scenario II, it is incorporated the additional stage called Phase 1 Treatment, which consists of a Clarification process followed by an Electrodialysis Reversal (EDR).This enables the recycling of 255.7 m3/h from the 350 m3/h previously discharged to the water body in Scenario I. In Scenario III, it is incorporated to the Scenario II setting an Evaporative Crystallization process for treating the concentrated brine resulting from the EDR process. This enables the recovery of more 55.4 m3/h from the 350 m3/h initially released, using, for that, the energy from residual steam previously not used by the refinery. The environmental analysis was developed through Life Cycle Assessment (LCA) and found very similar performances for all three scenarios. Despite that, the open profile analysis, of midpoint impacts, showed significant environmental gains from the closure of the water circuit and, though with very small advantages, Scenario III showed a better performance than Scenario II in all impact categories and, in most of them, also better than Scenario I performance. The single score analysis, considering endpoint impact categories, highlighted Climate Change, specially related to the natural gas burning in the boiler for steam generation, as the main impact category associated to the water life cycle within the refinery, being responsible for more than 90% of all the value of the single score indicator. The energetic analysis was developed using the Cumulative Energy Demand (CED) indicator and resulted in a better performance of Scenario I, even if with just small differences from Scenarios II and III. The worst performance was from Scenario II. Comparing the relative contribution of the different types of energy, the hydroelectricity was the most important one, being responsible for around 80% of the CED single score in all three scenarios. The economic analysis was developed through traditional indicators used for assessing projects viability Internal Return Rate (IRR) and Net Present Value (NPV), considering, as reference, the rules of charging for water use valid nowadays at the Paraíba do Sul river basin. With the prices charged nowadays for the water use from this basin, the implementation of both reuse scenarios is not economic viable. In order to make it viable, the charged value would have to be around 50 to 80 times higher than it is today. Among the reuse scenarios, Scenario II had a better economic performance than Scenario III.
8

Ermittlung der Energieeffizienz in der Tierhaltung am Beispiel der Milchviehhaltung

Kraatz, Simone 10 June 2009 (has links)
Die steigende Verknappung der Ressourcen bei stetigem Bevölkerungswachstum und der sich vollziehende Klimawandel erfordern Nachhaltigkeit in allen Ebenen der landwirtschaftlichen Produktion. Ziel dieser Arbeit war es eine allgemein anwendbare Methode zur Energiebilanzierung in der Tierhaltung am Beispiel der Milchviehhaltung zu entwickeln und darauf aufbauend Indikatoren zur Bewertung der Nachhaltigkeit des Energieeinsatzes im Milchproduktionsverfahren zu ermitteln. Anhand eines theoretischen Standardverfahrens der Milchproduktion wird eine Energieintensität von 3,54 MJ zur Herstellung von einem kg Milch bei einer definierten Einzeltierleistung von 8.000 kg Milch Kuh-1 Jahr-1 berechnet. Hierbei wird der kumulierte Energieaufwand (KEA) komplett dem Zielprodukt Milch zugeordnet. Stark beeinflussbar ist die Energieintensität durch die Fütterungsgestaltung, wobei beispielsweise ein steigender Kraftfutteranteil in der Ration die Energieintensität erhöht. Die Analyse der Daten von zwei Praxisbetrieben bestätigen die Ergebnisse. Aufgrund der Kuppelproduktentstehung in der Milchviehhaltung werden unterschiedliche Allokationsmethoden des KEA der Milchproduktion auf die einzelnen Produkte entwickelt und diskutiert. Die ermittelte Vorzugsmethode empfiehlt folgende Allokation des KEA auf die vier Kuppelprodukte: 59 % des KEA wird dem Zielprodukt Milch zugeordnet, 18 % der Schlachtkuh, 2 % dem Kalb und 21% den Exkrementen. Die Durchführung einer Fehlerfolgeabschätzung zeigt, dass Einzelunsicherheiten aufgrund der Vielzahl der einfließenden Parameter in der Energiebilanzierung der Milchproduktion nur geringen Einfluss auf den KEA haben. Der Einfluss von Verfahrensänderungen durch betriebs- und managementbedingte Entscheidungen auf den KEA ist bedeutend höher. Als geeigneter Indikator zur Bewertung der Nachhaltigkeit des Energieeinsatzes in der Tierhaltung wurde die Energieintensität ermittelt. Diskussionswertebereiche für die Energieintensität wurden definiert. / The scarcity of resources, the progressive growth of population and the climate change require sustainability in all levels of the agricultural production. The purpose of this research is to contribute to the development of a method for a generally accepted way of balancing energy in livestock husbandry at the example of dairy farming. Afterwards sustainability indicators were determined for the assessment of the sustainable use of energy in dairy farming. For a defined standard procedure which includes an animal performance of 8.000 kg milk cow-1 year-1, an energy intensity of 3.54 MJ per kg milk is calculated.The investigations show that the CED in dairy farming is strongly affected by the composition of the diet. Increasing pasture in the diet decreases the CED while concentrate in the diet has a reverse effect. Data analyses concerning the energy intensity at two farms confirm the results of the calculations. Dairy farming is a multi-output process. For that reason the allocation of the cumulative energy demand on the different products is done within the scope of a life cycle inventory analysis. The preferable solution of the allocation divides the cumulative energy demand on the four co-products as follows: 59 % for the milk production, 18% for producing beef from the dairy cow, 2% for the calf and 21% for the excrements. An uncertainty analysis is done to verify the influence of single uncertainties on the results of the calculations. As result an uncertainty of ± 6 % of the CED of the standard procedure was calculated. This uncertainty of the calculation has a lower influence on the CED than management related decisions on the cultural practices e.g. diet compositions and service life of the cows. Energy intensity in livestock husbandry has been determined as a useful indicator and therefore a reasonable part of an indicator system for the examination of the sustainability of agricultural production procedures.
9

Life cycle assessment of the semidetached passive house "Röda lyktan" in northern Sweden : A comparison between the construction phase and the use phase / Livscykelanalys av det tvådelade passivhuset "Röda lyktan" i norra Sverige : En jämförelse mellan konstruktionsfasen och användningsfasen

Svensson, Michelle January 2013 (has links)
This report is a life cycle assessment of a relatively newly built semidetached passive house/low energy house located in Östersund/Jämtland. The analysis concentrates on the building materials in the construction phase and the energy in the use phase for 50 years. The construction phase include frame, foundation, interior and exterior walls, ceiling and roof, middle floor structure, floor coverings, interior and exterior doors, windows, interior staircase with banisters, stove and FTX-ventilation system. The inventory to obtain the volume of each material has been made with the help of blueprints and interviews. The inventory of the use phase has been made using measurements from a parallel study by Itai Danielski of the energy use in the house (Danielski, Svensson &amp; Fröling, 2013). The database Ecoinvent has been used to get a result for the volume and energy values. The inventory data is allocated and the characterization methods GWP, CED (cumulative energy demand) and USEtox are used. The aim of this study was to compare the construction phase with the use phase to see which phase that has the highest energy values ​​and environmental impact. Another goal was to examine which materials in the construction phase that has the highest embodied energy and environmental impact. The result shows that in a comparison between the construction phase and the use phase, and when considering the parameters included in this study, the use phase has the highest values for global warming potentials (around 54 %), cumulative energy demand (around 80 %), ecotoxicity (around 56 %), human non-carcinogenic toxicity (around 77 %) and total human toxicity (around 75 %). The construction phase has the highest values for human carcinogenic toxicity (around 57 %). Even if the use phase has the highest values in most categories the construction phase also has high values. As buildings become more energy efficient and with increasing use of renewable energy, the construction phase becomes more important from an environmental perspective. This means that the material choices which are made in passive houses become increasingly important if passive houses should be considered to be environmentally friendly also in the future. The study also shows that the FTX-ventilation system, some of the insulation materials (with cellular plastic sheets and rock wool in top), metals (with sheet metal roofing of steel in top), glued laminated timber and wood fiber boards  have some of the highest values of environmental impact and the highest embodied energy. These materials should in future buildings be considered, if possible, to be replaced with materials with less environmental impact. / Den här rapporten är en livscykelanalys av ett relativt nybyggt passivhus/lågenergihus som också är ett parhus (ett hus delat i två separata lägenheter) beläget i Östersund/Jämtland. Analysen koncentrerar sig på byggnadsmaterialen i konstruktionsfasen och energin i användningsfasen under 50 år. Konstruktionsfasen inkluderar stomme, grund, inner- och ytterväggar, inner- och yttertak, mellanbjälklag, golvbeklädnader, inner- och ytterdörrar, fönster, invändig trappa med trappräcke, kamin och FTX-ventilationssystem. Inventeringen för att få fram volymen på varje material har gjorts med hjälp av ritningar och intervjuer. Inventeringen av användningsfasen har gjorts med hjälp av mätvärden från en parallell studie av Itai Danielski på energianvändningen i huset (Danielski, Svensson &amp; Fröling, 2013). Databasen Ecoinvent har sedan använts för att få fram ett resultat för volym- och energivärdena. Inventeringsdatan är allokerad och karaktäriseringsmetoderna GWP (globalt uppvärmingspotential), CED (kumulativt energibehov) och USEtox (toxicitet) har använts. Målet med studien är att jämföra konstruktionsfasen med användningsfasen för att kunna se vilken fas som har högst energivärden och miljöpåverkan. Målet är också att undersöka vilka material i konstruktionsfasen som har högst förkroppsligad energi och miljöpåverkan, i syftet att eventuellt kunna byta ut vissa material till miljövänligare alternativ, för att få ett miljövänligare hus i framtida liknande byggnationer. Resultaten visar att i en jämförelse mellan konstruktionsfasen och användningsfasen, och med hänsyn till de parametrar som ingår i studien, att användningsfasen har de högsta värdena för globalt uppvämingspotential (runt 54 %), kumulativt energibehov (runt 80 %), ekotoxicitet (runt 56 %), human icke-cancerogen toxicitet (runt 77 %) och total human toxicitet (runt 75 %). Konstruktionsfasen har högst värden för human cancerogen toxicitet (runt 57 %). Även om användningsfasen har högst värden i de flesta kategorierna så har även konstruktionsfasen höga värden. Ju mer energieffektiva husen blir och med en ökad användning av energi från förnyelsebara källor, desto viktigare blir konstruktionsfasen ur ett miljöperspektiv. Det betyder att materialvalen som görs i huset blir väldigt viktiga om passivhus ska fortsätta anses som miljövänliga även i framtiden. Denna studie visar också att FTX-ventilationssystemet, några av isoleringsmaterialen (med cellplasten och stenullen i topp), metallerna (med plåttaket av stål i topp), limträbalkar och träfiberskivor har några av de högsta värdena av miljöpåverkan och den högsta förkroppsligade energin. Dessa material borde i framtida byggnationer övervägas att om möjligt ersättas med andra material med mindre miljöpåverkan.

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