A questão energética é um dos principais desafios do século XXI. Por outro lado, os aspectos geopolíticos e ambientais, são fontes de preocupação para o modelo econômico atual. O Brasil é um país que apresenta vantagens em relação ao mundo em termos de utilização de fontes renováveis de energia. Desde 2007 os produtos da cana-de-açúcar assumiram o primeiro lugar na oferta de energia renovável. A análise de energia é necessária para o gerenciamento de recursos naturais limitados, para abastecer, com as mais diversas alternativas de biomassa, uma população mundial em constante crescimento. Essa análise identifica as práticas de produção e quantifica sua eficiência sob o ponto de vista energético, determinando a energia incorporada nas etapas do processo de produção. Estudos de energia incorporada em máquinas agrícolas são escassos. A participação do setor sucroalcooleiro na matriz energética do Brasil, fornecendo energia renovável a partir da biomassa tem aumentado. Devido à energia consumida no processo, ser produzida a partir dos seus próprios resíduos, avaliar as formas pelas quais a energia é demandada é vital para se determinar a viabilidade energética dessa fonte. Esse estudo visa determinar a energia incorporada em colhedora autopropelida de cana-de-açúcar. Foram avaliadas duas colhedoras, denominadas Máquina 1 equipada com rodas e pneus e Máquina 2 equipada com esteiras metálicas, fabricadas por uma companhia localizada na região de Piracicaba, Estado de São Paulo, Brasil. Para cada colhedora foi contabilizado o consumo dos insumos (diretos e indiretos) utilizados na fase de montagem, bem como, o consumo dos insumos utilizados na fase de manutenção e reparo. Os dados de consumo dos insumos foram processados apresentando os fluxos de materiais utilizados, os quais foram multiplicados pelo seu índice de energia incorporada, resultando na energia incorporada nos insumos. Os resultados demonstram que a Máquina 2 apresentou maior energia incorporada (204,3 MJ kg-1) do que a Máquina 1 (202,6 MJ kg-1) durante o ciclo de vida útil, isso foi influenciado diretamente pelo rodante utilizado pela máquina 2. A energia incorporada na mão-de-obra requerida para desempenhar a atividade de montagem foi baixa comparada com as outras categorias de energia. O aço carbono foi o insumo que obteve a maior representatividade de consumo. A energia incorporada indiretamente nos insumos foi baixa comparada com as verificadas nos demais insumos. Em termos de consumo de energia incorporada, a Máquina 1 é melhor que a Máquina 2, porém esta última propicia menores danos ao canavial, fato esse que pode compensar sua maior demanda energética ao longo de seu ciclo de vida. / The energy subject is one of the main challenges of 21st century. The geopolitical and environment aspects, they are concern sources to the current economic model. Brazil presents advantages in comparison to the world due to the use of renewable energy. Since 2007, products from the sugarcane have assumed the first place as a renewable source in the Brazilian energy matrix. Energy analysis is necessary in order to monitor of scarce natural resources, to supply, with the most several biomass alternatives, a world population in constant growth. This analysis identifies the production practices and quantifies their efficiency in the energy point of view, determining the embodied energy in the steps of the production process. Studies of embodied energy in agricultural machinery are rare. The participation of the sugarcane sector in the Brazilian energetic matrix has increased. Due to the energy consumed in their processes it is interesting to quantify these input flows in order to monitor the energy feasibility of this source. This study aimed to determine the embodied energy in the self-propelled sugarcane harvester. Two models were evaluated, so called: Machine 1 equipped with wheels and tires; and Machine 2 equipped with metallic tracks, manufactured by a company located at Piracicaba region, State of São Paulo, Brazil. For every harvester, the consumption of the input (direct and indirect) used in the assembly phase, was accounted, and also the consumption of the input used in the maintenance and repair phase. The consumption data of the inputs were processed presenting the materials flows used, which they were multiplied by their embodied energy indices, resulting in the embodied energy required by the production system. The results show that Machine 2 presented higher embodied energy (204.3 MJ kg-1) than the Machine 1 (202.6 MJ kg-1) during their life cycle and this was influenced directly by the rolling used by the Machine 2. The embodied energy by demanded by labor in the assembly activity was low compared with the other categories of energy. The steel carbon represented the input with the highest consumption. The incorporated energy indirectly in the input was low compared with the verified on the other inputs. In terms of embodied energy consumption, Machine 1 is better than Machine 2, although the latter may cause less damage to the sugarcane rattons which can compensate the higher energy demand in its life cycle.

Em substituição aos processos de reparo de defeitos por soldagem por arco elétrico, a Soldagem por Fricção com Pino Consumível ou Friction Hydro Pillar Processing (FHPP) vem sendo estudada devido a suas diversas vantagens sobre os processos convencionais de reparo. Isso se deve a não ocorrência de fusão do metal base e do metal de adição, ao reduzido tempo de processamento (inferior a um minuto, na maioria dos casos) e à possibilidade de automação do processo. Entretanto, por ser um processo relativamente novo, pouco se sabe sobre o mecanismo de deposição de material e a influência deste na qualidade final da junta soldada. Desta forma, a análise do fluxo de material proposta por esse estudo visa contribuir na compreensão da distribuição do material no interior da junta soldada. Para isso, um traçador de titânio foi inserido no interior da solda de um pino de aço SAE 4140. Para a avaliação das juntas soldadas com o traçador de titânio, foram feitas análises de macro e micrografia, além da análise por raios X por meio de um tomógrafo industrial. A partir dos resultados, constatou-se que o processo de FHPP apresenta dois fluxos distintos: o primeiro relativo à distribuição de material do centro do pino, já o segundo referente à distribuição de material da parede do pino. O material do centro do pino tem a tendência de acumular-se no fundo da solda e por meio dos planos de cisalhamento criados, o material do centro do pino é transportado para a periferia do pino. Já o segundo fluxo de material ocorre entre as superfícies de contato do pino e do furo. É um escoamento de expulsão de material, sendo expulso com a rebarba. Ainda, foi verificado que a mistura de material ocorre somente nas regiões onde há atrito entre as peças: ponta do pino com o fundo do furo, parede do pino com a parede do furo e no plano de cisalhamento a quente. Portanto, a partir do conhecimento do fluxo de material é possível prever a distribuição de particulados no interior da solda, uma vez que elas tendem a se acumular nas regiões com maior intensidade de fluxo. Além disso, a utilização da técnica de tomografia computacional mostrou-se eficaz na identificação de trincas no interior de juntas soldadas por fricção e também para as análises de fluxo em soldas com materiais dissimilares. / The replacement of electric arc welding at cracks repairs by the Friction Hydro Pillar Processing (FHPP) it`s being studied due the several advantages of this new process. With the FHPP the process time is less than one minute, the welding temperature is bellow to the melting temperature of the material and the process can be automated. However, as it is a relatively new repair welding process, there are not many information about the material distribution mechanism and the influence of it at the final weld quality. Thus, the material flow analysis proposed by this study intends to contribute to the material comprehension distribution inside the weld. Therefore, a titanium tracer was inserted inside a SAE 4140 steel pin. To evaluate the welds, the samples were analyzed by metallography and by industrial tomography. With the results, were found two different materials flows. The first describes the flow of the material at the center of the pin and the second describes the flow of the material of the faying surface of the pin. The material at the center of the pin tends to accumulate at the bottom of the weld and just above this few volume, appears the hot shear plane that allow the material from the center of the pin flows intermittent to the periphery. Nevertheless, this material is not expelled with the flash. The second flow is the material of the faying surface outside of the center pin, which on part goes to the top of the weld and it is expelled with the flash, and the other goes to the bottom of the weld, but doesn’t arrives because of the material already deposited. Furthermore, it was verified that the material stir occurs specially at the regions that the friction happens: faying surface of the pin and the hole and the shear plane. Thus, with that information it is possible to predict the distribution of particulate, as inclusions, inside the weld. Besides that, the industrial tomography proved that is able to identify cracks inside the welds and it is a great tool at the flow analysis of dissimilar welds.

The systems analysis of biomass in the Borås municipality is conducted so as to identify the amount of biomass consumed by certain designated systems for this study. Using the principles of urban metabolism and material flow accounting, the system boundary is setup and biomass is categorized into system specific entities which are to be quantified. The symbiosis principle and the cascading approach of resource utilization are used to determine the systems which are working together and the resources they share among each other. Selected flows are established to be calculated for paper and paper products; fuel and construction wood; biogas; and blended transportation fuels. The flows are considered one by one, it is found that the consumption system and the waste management system are main players in the flow of paper and its products. The flow of fuel and construction wood is surveyed across different companies in the municipality for 2013. The fate of the waste construction wood for 2011 is traced across the waste handling systems of Borås Energi och Miljö till the Combined Heat and Power plant at Ryaverket. The quantities of fuel wood consumed by the CHP and residential heat are received from statistical sources. The main players in the biogas production flow are the waste management system and the digesters at Gässlösa and Sobacken. The consumption of enriched biogas is then examined for different transportation sub-systems. The flows for blended fuels is considered for petrol, diesel; separately analysed from them are their blended quantities of ethanol and other renewable additives. The sold quantities of petrol and diesel have been received from the market survey for the year 2013. The flows are then individually validated by common critical parameters to determine how reliable the information sources are. The resulting flows are discussed for the symbiosis of resources and significance of urban metabolism concepts. / Program: Masterutbildning i energi- och materialåtervinning

A questão energética é um dos principais desafios do século XXI. Por outro lado, os aspectos geopolíticos e ambientais, são fontes de preocupação para o modelo econômico atual. O Brasil é um país que apresenta vantagens em relação ao mundo em termos de utilização de fontes renováveis de energia. Desde 2007 os produtos da cana-de-açúcar assumiram o primeiro lugar na oferta de energia renovável. A análise de energia é necessária para o gerenciamento de recursos naturais limitados, para abastecer, com as mais diversas alternativas de biomassa, uma população mundial em constante crescimento. Essa análise identifica as práticas de produção e quantifica sua eficiência sob o ponto de vista energético, determinando a energia incorporada nas etapas do processo de produção. Estudos de energia incorporada em máquinas agrícolas são escassos. A participação do setor sucroalcooleiro na matriz energética do Brasil, fornecendo energia renovável a partir da biomassa tem aumentado. Devido à energia consumida no processo, ser produzida a partir dos seus próprios resíduos, avaliar as formas pelas quais a energia é demandada é vital para se determinar a viabilidade energética dessa fonte. Esse estudo visa determinar a energia incorporada em colhedora autopropelida de cana-de-açúcar. Foram avaliadas duas colhedoras, denominadas Máquina 1 equipada com rodas e pneus e Máquina 2 equipada com esteiras metálicas, fabricadas por uma companhia localizada na região de Piracicaba, Estado de São Paulo, Brasil. Para cada colhedora foi contabilizado o consumo dos insumos (diretos e indiretos) utilizados na fase de montagem, bem como, o consumo dos insumos utilizados na fase de manutenção e reparo. Os dados de consumo dos insumos foram processados apresentando os fluxos de materiais utilizados, os quais foram multiplicados pelo seu índice de energia incorporada, resultando na energia incorporada nos insumos. Os resultados demonstram que a Máquina 2 apresentou maior energia incorporada (204,3 MJ kg-1) do que a Máquina 1 (202,6 MJ kg-1) durante o ciclo de vida útil, isso foi influenciado diretamente pelo rodante utilizado pela máquina 2. A energia incorporada na mão-de-obra requerida para desempenhar a atividade de montagem foi baixa comparada com as outras categorias de energia. O aço carbono foi o insumo que obteve a maior representatividade de consumo. A energia incorporada indiretamente nos insumos foi baixa comparada com as verificadas nos demais insumos. Em termos de consumo de energia incorporada, a Máquina 1 é melhor que a Máquina 2, porém esta última propicia menores danos ao canavial, fato esse que pode compensar sua maior demanda energética ao longo de seu ciclo de vida. / The energy subject is one of the main challenges of 21st century. The geopolitical and environment aspects, they are concern sources to the current economic model. Brazil presents advantages in comparison to the world due to the use of renewable energy. Since 2007, products from the sugarcane have assumed the first place as a renewable source in the Brazilian energy matrix. Energy analysis is necessary in order to monitor of scarce natural resources, to supply, with the most several biomass alternatives, a world population in constant growth. This analysis identifies the production practices and quantifies their efficiency in the energy point of view, determining the embodied energy in the steps of the production process. Studies of embodied energy in agricultural machinery are rare. The participation of the sugarcane sector in the Brazilian energetic matrix has increased. Due to the energy consumed in their processes it is interesting to quantify these input flows in order to monitor the energy feasibility of this source. This study aimed to determine the embodied energy in the self-propelled sugarcane harvester. Two models were evaluated, so called: Machine 1 equipped with wheels and tires; and Machine 2 equipped with metallic tracks, manufactured by a company located at Piracicaba region, State of São Paulo, Brazil. For every harvester, the consumption of the input (direct and indirect) used in the assembly phase, was accounted, and also the consumption of the input used in the maintenance and repair phase. The consumption data of the inputs were processed presenting the materials flows used, which they were multiplied by their embodied energy indices, resulting in the embodied energy required by the production system. The results show that Machine 2 presented higher embodied energy (204.3 MJ kg-1) than the Machine 1 (202.6 MJ kg-1) during their life cycle and this was influenced directly by the rolling used by the Machine 2. The embodied energy by demanded by labor in the assembly activity was low compared with the other categories of energy. The steel carbon represented the input with the highest consumption. The incorporated energy indirectly in the input was low compared with the verified on the other inputs. In terms of embodied energy consumption, Machine 1 is better than Machine 2, although the latter may cause less damage to the sugarcane rattons which can compensate the higher energy demand in its life cycle.

A new approach to allocate environmental responsibility, the "value added-based responsibility" allocation, is presented in this article. This metric allocates total environmental pressures occurring along an international supply chain to the participating sectors and countries according to the share of value added they generate within that specific supply chain. We show that - due to their position in global value chains - certain sectors (e.g. services) and countries (e.g. Germany) receive significantly greater responsibility compared to other allocation approaches. This adds a new perspective to the discussions concerning a fair distribution of mitigation costs among nations, companies and consumers.

Majority of the products get discarded at end-of-life (EoL), causing environmental pollution, and resulting in a complete loss of all materials and embodied energy. Adopting a closed-loop material flow approach can aid preventing such losses and enable EoL value recovery from these products. Design and engineering decisions made and how products are used impact the capability to implement EOL strategies such as disassembly and remanufacturing. Some underlying factors affecting the capability to implement these EOL strategies have been discussed in previous studies. However, relevant metrics and attributes are not well defined and comprehensive methods to quantitatively evaluate them are lacking. This study will first identify key lifecycle oriented metrics affecting disassemblability and remanufacturability. Then a methodology is proposed for the quantitative evaluation of these strategies considering the quality of returns, product-design characteristics and process technology requirements. Finally, an industrial case-study is presented to demonstrate the application of the proposed method.

Friction stir welding (FSW) is a relatively new solid-state welding technology invented at The Welding Institute of UK in 1991. It is versatile and has been widely adopted to join various materials. There has been strong research activity on revealing the details of the material flow pattern in the nugget zone induced by the conventional shoulder tool. However, there is insufficient understanding on the aspects of the scroll shoulder tool design and the shoulder flow zone formation utilizing this type of tool. The major objective of this study was to conduct experiments, analyse results and then reveal the shoulder flow zone forming mechanism for the scroll shoulder tool. The method used was to identify the flow pattern in the shoulder flow zone using a ‘marker insert’ technique, and then to suggest the forming mechanism of the shoulder flow zone based on the obtained flow pattern; although the ‘marker insert’ technique has never been used to study the shoulder flow zone flow pattern induced by the scroll shoulder tool. Experiments were conducted to examine the thick sections 6061 aluminium ‘marker insert’ welds, which were welded using a scroll shoulder tool at a range of welding parameters. These were followed by quantifying the mass of the accumulated work piece material within the scroll groove (pick up material-PUM), evaluating the effect of welding parameters on the shoulder flow zone formation, and documenting the shoulder flow zone flow pattern. The major finding was that there is a simple banded structure which forms in a layer to layer manner in the bottom portion of the shoulder flow zone, but it disappears in the top portion of the shoulder flow zone. Accordingly, the forming mechanism of the shoulder flow zone for the scroll shoulder tool was suggested as follows. Firstly, the tool pin is plunged into the work piece; the work piece material is extruded by the pin and pushed up into the scroll groove forming the PUM. Secondly, after the tool shoulder is plunged into the work piece to a certain depth, the scroll groove is fully filled up with the PUM. Finally, during the forward movement of the tool, the central portion of PUM is driven downward by the root portion of the pin and then detaches from the pin (tip portion) in a layer to layer manner. It has also found that the thickness of the shoulder flow zone varies with a thicker on the advancing side than on the retreating side, and there is a positive linear relationship between the mass of PUM and the weld quality. This study has revealed for the first time the forming mechanism of the shoulder flow zone, and has improved the understanding of the shoulder flow zone formation using a scroll shoulder tool. It is recommended that a ‘shoulder-breaking’ technique is developed to break the rotating shoulder suddenly and hence embed it into the work piece during FSW, in which a real-time shoulder-work piece couple could be produced for a better three-dimensional examination of the shoulder flow zone.

<p>The BMW Group uses load units for the transportation of assembly parts from the suppliers to the plants and for the internal material flow. This thesis analyses the advantageousness of introducing a load unit with a new size. There are three reasons why the current choice of containers is not sufficient. Firstly, there is a certain range of assembly parts that does not fit very well into the existing standard load units. Secondly, the average measurements of the parts have grown in the last years and thirdly, several of the existing containers leave unused space in the transportation vehicles.</p><p>For this the relevant costs and other, more qualitative aspects like the placing at the assembly line are considered. A container size is identified that offers a significant savings potential. For this potential the handling and transportation costs are identified as the relevant leverages. These costs are found to depend mainly on the utilisation degree of the load units.</p><p>To calculate the different utilisation degrees, a packing-algorithm in form of a four-block heuristic is applied and its results are extrapolated on the basis of existing BMW packing information. Thus, several assembly parts are identified that fit better into the suggested load unit than in the existing ones. These results are assessed using BMW’s expense ratios for handling and transportation. 80 parts are determined for which the migration to the new size would result in savings of more than 5,000 EUR for each per year in Dingolfing. Together, these parts offer a savings potential of about 0.9 million Euro.</p>

The BMW Group uses load units for the transportation of assembly parts from the suppliers to the plants and for the internal material flow. This thesis analyses the advantageousness of introducing a load unit with a new size. There are three reasons why the current choice of containers is not sufficient. Firstly, there is a certain range of assembly parts that does not fit very well into the existing standard load units. Secondly, the average measurements of the parts have grown in the last years and thirdly, several of the existing containers leave unused space in the transportation vehicles. For this the relevant costs and other, more qualitative aspects like the placing at the assembly line are considered. A container size is identified that offers a significant savings potential. For this potential the handling and transportation costs are identified as the relevant leverages. These costs are found to depend mainly on the utilisation degree of the load units. To calculate the different utilisation degrees, a packing-algorithm in form of a four-block heuristic is applied and its results are extrapolated on the basis of existing BMW packing information. Thus, several assembly parts are identified that fit better into the suggested load unit than in the existing ones. These results are assessed using BMW’s expense ratios for handling and transportation. 80 parts are determined for which the migration to the new size would result in savings of more than 5,000 EUR for each per year in Dingolfing. Together, these parts offer a savings potential of about 0.9 million Euro.

La presente tesis se compone de tres artículos publicados y uno enviado para publicación. Son cuatro casos de estudio que comparten el mismo eje teórico: el metabolismo social. Usando la metodología Contabilidad de Flujos de Materiales se han medido las entradas de materiales de varias economías. Los indicadores que se obtienen aplicando esta metodología permiten caracterizar los perfiles metabólicos de las economías estudiadas, identificando los factores más importantes que los determinan. Asimismo, estos indicadores pueden considerarse como una medida indirecta de la presión que una economía ejerce en el medio ambiente. Por otra parte, esta tesis tiene como objetivo dar evidencia empírica sobre la ausencia de desmaterialización de las economías. La principal conclusión es que en este mundo globalizado, los países son cada vez más dependientes del comercio internacional y el papel que un país juega en el concierto internacional determina en gran medida la manera como utiliza sus recursos materiales. Sin embargo, esta dependencia sigue diversas trayectorias. Por una parte, identificamos un conjunto de países como España que se ha beneficiado de este proceso. En las últimas dos décadas, este país ha logrado aumentar su bienestar económico usando intensivamente recursos provenientes de otros sistemas socioeconómicos, como el petróleo. Sin embargo, el principal factor determinante de su perfil biofísico ha sido el sector de la construcción. Por otra parte, identificamos aquellos países que históricamente han basado sus economías en la extracción de recursos naturales como Chile, Ecuador, México y Perú y que actualmente no presentan un patrón uniforme de uso de recursos naturales. En Ecuador, Chile y Perú, el comercio internacional ha sido el principal determinante del patrón e intensidad del uso de los recursos naturales. Sin embargo, Ecuador sigue siendo el ejemplo típico de economía extractiva mientras que Chile ha logrado una diversificación de sus exportaciones con mayor valor agregado. Este proceso se observa pero de manera muy incipiente en Perú. Chile puede considerarse como el ejemplo más exitoso en la región del modelo basado en exportaciones de materias primas al lograr un fuerte crecimiento económico. México es un caso especial y contradictorio, porque a pesar de ser un importante exportador de petróleo, ha logrado una diversificación de su producción hacía sectores con un mayor componente tecnológico debido a la creciente presencia de la industria maquiladora. Sin embargo, no son sus flujos de exportaciones ni el crecimiento económico los principales determinantes del uso que hace de sus recursos materiales sino el crecimiento de la población. Por otra parte, se observa un incremento considerable en el uso de materiales de construcción y energéticos fósiles en toda la economía mientras que al mismo tiempo, la población rural sigue dependiendo de fuentes tradicionales de energía como la leña para satisfacer sus necesidades energéticas. Otra conclusión general es que no se observa un proceso de desmaterialización ni absoluta ni relativa en ninguno de los países analizados. / This thesis is composed of three published articles and a submitted one. All share the same theoretical approach: social metabolism. By tracing all material flows into several economic systems by means of the Material Flows Accounting methodology (MFA), this thesis aims on the one hand at characterizing current metabolic profiles of different economies, identifying their main driving forces; on the other hand, it aims at providing empirical evidence on dematerialisation of the economies. The main conclusion is that in our globalised world, countries are becoming more dependent on international trade and that the role a country plays in the international markets strongly determines its pattern of material use. This dependency followed different trajectories. On the one hand, we identify countries such as Spain that benefited from this process as it increased welfare based in an intensive use of strategic natural resources coming from other economic systems such as fossil fuels. Nevertheless, the main driving force shaping the biophysical profile of this economy was the construction sector, an internal factor. On the other hand, we identify those countries that historically have relied on the extraction of natural resources such as Chile, Ecuador, Mexico and Peru although we can no longer talk about a uniform pattern of natural resource use in the region. In Ecuador, Chile and Peru, international trade was the main driving force for material use. Ecuador remains the typical example of an extractive economy whereas a diversification of exports away from bulk commodities towards products with more added value could be observed to a greater extent in Chile and incipiently in Peru. Chile can be regarded as a successful example of the staple theory of growth as its GDP increased considerably. Mexico is a special and contradictory case. Firstly, despite being an important oil exporter, it has achieved a diversification of production, moving towards technology-intensive products due to the assembly industries. Secondly, despite it has a great potential of biomass extraction, it is undergoing a substitution process of imported biomass for national biomass, in particular, basic crops for human consumption. Instead of international trade, population growth was the main driving force for biophysical growth in this economy. Thirdly, it was observed an increasing emphasis on the use of construction materials and fossil fuels in the whole economy whereas in the countryside, rural households still rely heavily on traditional biomass flows such as fuelwood to satisfy their energetic needs. A general conclusion is that neither absolute dematerialisation nor relative dematerialisation occurred in any of the analysed countries.