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Abstract(s)
A presente dissertação representa o trabalho desenvolvido na empresa ISQ (Instituto de Soldadura e Qualidade), em conjunto com o ISEP, no contexto da unidade curricular Dissertação/Projeto/Estágio do Mestrado em Energias Sustentáveis. O foco desta dissertação foi o estudo de medidas que permitam a mitigação das alterações climáticas originadas pelo setor automóvel, sendo este setor um dos maiores responsáveis pelas emissões de gases com efeito de estufa (GEE). Foram estudadas três estratégias com potencial de redução dos impactes ambientais: seleção do sistema de propulsão, aplicação de materiais leves e cenários de fim-de-vida (FdV). Para isto foi conduzida uma revisão sistemática da literatura relativa ao setor automóvel que aplicasse a avaliação de ciclo de vida (ACV) a pelo menos uma das três estratégias mencionadas, segundo uma das duas categorias de impacte: consumo primário de energia (CPE) e potencial de aquecimento global (PAG). O valor desta dissertação encontra-se, sobretudo, na análise simultânea de diferentes artigos com diferentes características, ultrapassando obstáculos, como: diferentes casos de estudo, distância percorrida, cenários de FdV, limitações do sistema e diferente formatação de resultados. Desta forma, é possível identificar as opções mais benéficas e mais prejudiciais no ciclo de vida (CV) do veículo e quais os pontos sensíveis em cada estratégia, disponibilizando impactes quantificados que podem vir a ser aplicados noutros estudos, dados estes difíceis de encontrar sistematizados na literatura. O sistema de propulsão demonstra como as alternativas eletrificadas têm potencial na redução de impactes, principalmente, na fase de utilização. Contudo, a sua etapa produtiva, contrariamente aos convencionais, tem associados elevados impactes, devendo-se isto, sobretudo, às baterias de ião lítio (Li-ion) onde as alternativas 100% eletrificadas apresentam os maiores impactes. Conclui-se que quanto maior a distância percorrida, maiores as vantagens ambientais associadas à utilização das opções eletrificadas relativamente às opções convencionais. Os aspetos mais sensíveis identificados incluem o mix energético do país onde é realizado o estudo, modo de obtenção do hidrogénio (H2) para as alternativas movidas a H2, fator de utilidade (FU) dos veículos híbridos plug-in e combustível utilizado para os veículos que o utilizam, devendo priorizar-se os biocombustíveis relativamente ao gás natural, gasolina e diesel. Os materiais leves também apresentam potencial relativamente aos convencionais/ pesados, contudo nem sempre os superam. Isto deve-se a quão intensiva é a sua fase de produção, que, por exemplo, para os compósitos inibe o seu bom desempenho na fase de utilização, enquanto os materiais convencionais apresentam impactes significativamente inferiores. No entanto, os materiais alternativos não só têm uma fase de utilização bastante menos intensiva, como também alcançam compensações superiores no FdV. Também nesta estratégia o aumento da distância percorrida, provoca uma melhoria no desempenho das alternativas inovadoras. Os aspetos que merecem uma atenção especial na aplicação de materiais alternativos compreendem: redimensionamento do sistema de propulsão, reduções secundárias de massa, abordagem ACV selecionada, contexto/país onde são produzidos os materiais, incorporação de materiais secundários na produção de componentes e cenários de FdV aplicados. A análise da estratégia de FdV permitiu reforçar a potencialidade dos materiais alternativos nesta etapa relativamente aos convencionais. Os impactes para cada material dependem consideravelmente do cenário de FdV selecionado, verificando-se uma elevada amplitude nos resultados obtidos. Parâmetros como a inclusão de material biológico e reciclado na produção dos componentes e abordagem selecionada para a ACV também afetam os impactes quantificados. A análise desta estratégia permite concluir que a melhor alternativa acaba por depender mais do cenário de FdV do que do material selecionado. A etapa de produção das alternativas inovadoras, tanto para o sistema de propulsão como para os materiais leves, deve ser um tema a expandir de forma a desenvolver tecnologias que permitam a redução dos seus impactes ambientais. Também a identificação dos melhores contextos para utilização de determinados sistemas de propulsão e produção de certos materiais alternativos deve ser efetuada. As tecnologias de FdV comprovaram a elevada influência no ciclo de vida total dos componentes, merecendo assim ser estudadas no âmbito da economia circular, desenvolvendo procedimentos avançados com potencial de redução nos impactes. O ideal seria a implementação das três estratégias em simultâneo, sendo benéfico, para isto, um estudo da perspetiva de CV de um veículo onde estas fossem aplicadas. Aqui seria considerada a combinação de diferentes tecnologias, avaliando diferentes caminhos e respetivas compatibilizações de alternativas entre estratégias que permitissem as maiores reduções nos impactes ambientais no CV do veículo. A nível nacional deve ser estudado e aprofundado o promissor mix energético que identifica Portugal como um bom contexto para implementação das tecnologias eletrificadas, mitigando assim os impactes ambientais associados ao setor automóvel. Para além disto, deve ser analisada a margem de crescimento de Portugal na produção automóvel, dada a sua dimensão neste âmbito e, por isso, responsabilidade associada.
The present dissertation represents the work developed in the organization ISQ (Instituto de Soldadura e Qualidade), together with ISEP, in the context of the discipline Dissertation/Project/Internship in its Master’s Degree in Sustainable Energies. The focus of this dissertation was the study of measures allowing the mitigation of climate change through the automotive sector, this sector being one of the most responsible for the greenhouse gases emissions (GHG). Three strategies with the potential of reducing environmental impacts were studied: propulsion systems selection, lightweighting materials application and end-of-life (EoL) scenarios. For this, a systematic literature review, existent in the automotive sector applying a life cycle assessment (LCA), was conducted, according to one of the two impact categories: primary energy demand (PED) and global warming potential (GWP). The relevance of this dissertation finds itself, mainly, in the simultaneous analysis of several articles with different features that in another way would not be possible, overcoming obstacles, as, different case studies, distances travelled, EoL scenarios, system limitations and different format of results. This way, it was possible to identify the most beneficial and most prejudicial options to the vehicle’s life cycle (LC) and sensitive aspects in each strategy, providing quantified impacts that can be applied in other studies and that are difficult to find systematized in the literature. The propulsion system demonstrates the potential electrified alternatives have to reduce impacts, especially, in the use phase. However, its productive stage, contrarily to the conventional ones, has associated high impacts, which is mainly due to the lithiumion (Li-ion) batteries, where the 100% electrified alternative showed the highest impacts. It could be concluded that the higher the distance travelled, the higher the environmental advantages associated to the utilization of the electrified options, relatively to the conventional ones. The most sensitive aspects identified include the energy mix of the country where the study was conducted, method of hydrogen (H2) production for the alternatives powered on H2, utility factor (UF) of plug-in hybrid vehicles and fuel used for combustion engine vehicles, where biofuels must be prioritized relatively to natural gas, gasoline and diesel. Lightweighting materials also present potential when compared to the conventional/ heavy ones, however not always overcome them. This is due to how intensive is its production phase. An example is that composite material inhibits its good performance in the use phase, while conventional materials present significatively lower impacts. Nevertheless, alternative materials not only have a use phase considerably less intensive, but also achieve higher offsets in the EoL. In this strategy, the increase of distance travelled also leads to an improvement of the performance of the innovative alternatives. The aspects that deserve a special attention in the application of lightweighting materials include: resizing of the propulsion system, secondary mass reductions, LCA selected approach, context/country where the materials are produced, incorporation of secondary materials in the components manufacture and EoL scenarios applied. The analysis of EoL strategy enabled the reinforcement of the potential of alternative materials in this stage relatively to the conventional ones. The impacts for each material considerably depend on the selected EoL scenario, showing an high range in the obtained results. Parameters including inclusion of biological and secondary material in the components manufacture and LCA selected approach also affect the quantified impacts. The analysis of this strategy allows to conclude that the best alternative tends to depend more on the EoL scenario than on the material selected. The production stage of innovative alternatives, both for the propulsion system and lightweighting materials, must be a subject to expand in order to develop technologies allowing the reduction of its environmental impacts. Also, the identification of the best contexts for the use of determined propulsion systems and production of certain alternative materials must be undertaken. The EoL technologies demonstrate a high influence in the total component’s LC, making it worth being studied through the circular economy scope, developing advanced procedures with potential for impacts reduction. The ideal path would be the implementation of the three strategies simultaneously, making it beneficial, at this level, the study, in a LC perspective, of a vehicle where they were applied. Here, it would be considered a combination of different technologies, evaluating different pathways and respective compatibilities of alternatives among strategies, allowing the highest reductions of environmental impacts in the vehicle LC. At a national level, the promising energetic mix that identifies Portugal as a good context to implement the electrified technologies, must be studied and deepen, this way mitigating the environmental impacts associated with the automotive sector. In addition, the Portugal leeway growth in the automotive production should be analysed, given its dimension in this ambit and, therefore, associated responsibility.
The present dissertation represents the work developed in the organization ISQ (Instituto de Soldadura e Qualidade), together with ISEP, in the context of the discipline Dissertation/Project/Internship in its Master’s Degree in Sustainable Energies. The focus of this dissertation was the study of measures allowing the mitigation of climate change through the automotive sector, this sector being one of the most responsible for the greenhouse gases emissions (GHG). Three strategies with the potential of reducing environmental impacts were studied: propulsion systems selection, lightweighting materials application and end-of-life (EoL) scenarios. For this, a systematic literature review, existent in the automotive sector applying a life cycle assessment (LCA), was conducted, according to one of the two impact categories: primary energy demand (PED) and global warming potential (GWP). The relevance of this dissertation finds itself, mainly, in the simultaneous analysis of several articles with different features that in another way would not be possible, overcoming obstacles, as, different case studies, distances travelled, EoL scenarios, system limitations and different format of results. This way, it was possible to identify the most beneficial and most prejudicial options to the vehicle’s life cycle (LC) and sensitive aspects in each strategy, providing quantified impacts that can be applied in other studies and that are difficult to find systematized in the literature. The propulsion system demonstrates the potential electrified alternatives have to reduce impacts, especially, in the use phase. However, its productive stage, contrarily to the conventional ones, has associated high impacts, which is mainly due to the lithiumion (Li-ion) batteries, where the 100% electrified alternative showed the highest impacts. It could be concluded that the higher the distance travelled, the higher the environmental advantages associated to the utilization of the electrified options, relatively to the conventional ones. The most sensitive aspects identified include the energy mix of the country where the study was conducted, method of hydrogen (H2) production for the alternatives powered on H2, utility factor (UF) of plug-in hybrid vehicles and fuel used for combustion engine vehicles, where biofuels must be prioritized relatively to natural gas, gasoline and diesel. Lightweighting materials also present potential when compared to the conventional/ heavy ones, however not always overcome them. This is due to how intensive is its production phase. An example is that composite material inhibits its good performance in the use phase, while conventional materials present significatively lower impacts. Nevertheless, alternative materials not only have a use phase considerably less intensive, but also achieve higher offsets in the EoL. In this strategy, the increase of distance travelled also leads to an improvement of the performance of the innovative alternatives. The aspects that deserve a special attention in the application of lightweighting materials include: resizing of the propulsion system, secondary mass reductions, LCA selected approach, context/country where the materials are produced, incorporation of secondary materials in the components manufacture and EoL scenarios applied. The analysis of EoL strategy enabled the reinforcement of the potential of alternative materials in this stage relatively to the conventional ones. The impacts for each material considerably depend on the selected EoL scenario, showing an high range in the obtained results. Parameters including inclusion of biological and secondary material in the components manufacture and LCA selected approach also affect the quantified impacts. The analysis of this strategy allows to conclude that the best alternative tends to depend more on the EoL scenario than on the material selected. The production stage of innovative alternatives, both for the propulsion system and lightweighting materials, must be a subject to expand in order to develop technologies allowing the reduction of its environmental impacts. Also, the identification of the best contexts for the use of determined propulsion systems and production of certain alternative materials must be undertaken. The EoL technologies demonstrate a high influence in the total component’s LC, making it worth being studied through the circular economy scope, developing advanced procedures with potential for impacts reduction. The ideal path would be the implementation of the three strategies simultaneously, making it beneficial, at this level, the study, in a LC perspective, of a vehicle where they were applied. Here, it would be considered a combination of different technologies, evaluating different pathways and respective compatibilities of alternatives among strategies, allowing the highest reductions of environmental impacts in the vehicle LC. At a national level, the promising energetic mix that identifies Portugal as a good context to implement the electrified technologies, must be studied and deepen, this way mitigating the environmental impacts associated with the automotive sector. In addition, the Portugal leeway growth in the automotive production should be analysed, given its dimension in this ambit and, therefore, associated responsibility.
Description
Keywords
Avaliação de ciclo de vida Consumo primário de energia Materiais leves Potencial de aquecimento global Setor automóvel Sistema de propulsão Automotive sector Global warming potential Life cycle assessment Lightweighting materials Primary energy demand Propulsion system