La prise en compte des impacts environnementaux liés à la Fabrication Additive (FA) est un sujet encore en développement et loin d'être consolidé. Cette thèse tente de répondre à la question suivante: Comment identifier et maîtriser les impacts environnementaux liés à la mise en usage des technologies de Fabrication Additive ?Une approche centrée sur l’analyse de scénarios d’usages a été appliquée. Trois scénarios ont été identifiés et étudiés: 1) La Fabrication Personnelle; 2) l’Utilisation commerciale de la FA et 3) l’Utilisation Industrielle de la FA. L'analyse de la littérature et l’application de la méthode d’Analyse du Cycle de Vie – ACV ont fourni les données nécessaires afin d’identifier les différents hotspots environnementaux dans chaque scénario.Pour le cas de la « Fabrication Personnelle », l'étude souligne l'importance de mettre en évidence les aspects humains. La façon dont les gens utilisent la technologie génère bien souvent plus d’impact que la technologie elle-même. Pour le cas du scénario «Utilisation Commerciale», c’est la phase de production qui génère le plus d'impacts environnementaux, en raison de la consommation d’énergie du processus d'impression. Les résultats du scénario « Utilisation Industriel», avec l’utilisation de la technologie EBM, indiquent que la consommation d’énergie du processus d'impression, la fabrication de poudre, ainsi que les processus de Finition sont les principales sources d’impacts.Les résultats des trois études ont été analysés et rassemblés de manière à concevoir un cadre systémique montrant les contributeurs aux impacts dans le cas de la mise en usage de technologies de FA. Quatre groupes de contributeurs ont ainsi été identifiés en lien avec: le produit, le processus d'impression (aspects techniques), et le niveau d'expérience de l'utilisateur en matière de CAO et d'impression (aspects humains). Pour chaque groupe, plusieurs contributeurs ont été associés (consommation d’énergie, masse du produit, temps d’usage de la CAO,…). A partir de ce cadre, nous avons pu construire un modèle simplifié pour l’ACV adapté au cas de la mise en usage de la FA. Il a donné lieu à l’élaboration d’un démonstrateur pour estimer les impacts environnementaux liés à la mise en usage de la fabrication additive. / The subject of the environmental impacts related to Additive Manufacturing is evolving and far from being consolidated. This thesis tries to answer the following question: How to identify and control the environmental impacts associated to the use of Additive Manufacturing technologies? An approach centred on scenarios was applied. Three specific scenarios were identified and studied: 1) Personal Fabrication; 2) Business use of AM and 3) Industrial use of AM. Literature analysis and the use of the Life Cycle Assessment-LCA approach provided accurate data to identify the different hotspots of environmental impacts in each scenario.In the Personal Fabrication case, the study highlights the importance of placing a greater focus on the Human aspects. The way people use the technology often generates more impacts than the technology itself. In the ‘Business’ scenario the findings show that the energy consumed in Production phase is the most representative phase in terms of environmental impacts. Results from the ‘Industrial’ scenario using EBM technology suggests that the energy consumption of the Printing Process, the powder manufacturing, as well as the Post-treatment process are the main sources of the environmental impacts.The results of the three studies were analysed and gathered in such a way to design a systemic framework of impacts in the case of AM use. Four group of impacts drivers are recognised: The product and the Printing Process (Technical aspects) and the User’s level of experience in CAD and Printing (Human Aspects). For each group, several impact contributors are identified (product height, CAD use time, etc.). From this framework, an adapted LCA model was designed and a software concept was created to estimate the environmental impacts related to use of AM technologies.

abstract: In recent years, the length of time people use and keep belongings has decreased. With the acceptance of short-lived furniture and inexpensive replacements, the American mentality has shifted to thinking that discarding furniture is normal, often in the guise of recycling. Americans are addicted to landfills. The high cost of landfill real estate and other considerable ecological impacts created by the manufacturing of furniture should persuade people to give their belongings a longer life, but in reality, furniture is often prematurely discarded. This grounded theory study takes a multi-method approach to analyze why some types of furniture are kept longer and to theorize about new ways to design and sell furniture that lasts well past its warranty. Case studies bring new insight into designer intention, manufacturer intent, the world of auction-worthy collectables and heirlooms, why there is a booming second-hand furniture market and the growing importance of informed interior designers and architects who specify or help clients choose interior furnishings. An environmental life cycle assessment compares how the length of furniture life affects environmental impacts. A product's life could continue for generations if properly maintained. Designers and manufacturers hoping to promote longevity can apply the conclusions of this report in bringing new pieces to the market that have a much longer life span. This study finds areas of opportunity that promote user attachment, anticipate future repurposing, and provide services. This thinking envisions a paradigm for furniture that can re-invent itself over multiple generations of users, and ultimately lead to a new wave of desirable heirloom furniture. / Dissertation/Thesis / M.S.D. Design 2011

abstract: In recent years environmental life-cycle assessments (LCA) have been increasingly used to support planning and development of sustainable infrastructure. This study demonstrates the application of LCA to estimate embedded energy use and greenhouse gas (GHG) emissions related to materials manufacturing and construction processes for low and high density single-family neighborhoods typically found in the Southwest. The LCA analysis presented in this study includes the assessment of more than 8,500 single family detached units, and 130 miles of related roadway infrastructure. The study estimates embedded and GHG emissions as a function of building size (1,500 - 3000 square feet), number of stories (1 or 2), and exterior wall material composition (stucco, brick, block, wood), roof material composition (clay tile, cement tile, asphalt shingles, built up), and as a function of roadway typology per mile (asphalt local residential roads, collectors, arterials). While a hybrid economic input-out life-cycle assessment is applied to estimate the energy and GHG emissions impacts of the residential units, the PaLATE tool is applied to determine the environmental effects of pavements and roads. The results indicate that low density single family neighborhoods are 2 - 2.5 X more energy and GHG intensive, per residential dwelling (unit) built, than high density residential neighborhoods. This relationship holds regardless of whether the functional unit is per acre or per capita. The results also indicate that a typical low density neighborhood (less than 2 dwellings per acre) requires 78 percent more energy and resource in roadway infrastructure per residential unit than a traditional small lot high density (more than 6 dwelling per acre). Also, this study shows that new master planned communities tend to be more energy intensive than traditional non master planned residential developments. / Dissertation/Thesis / M.U.E.P. Urban and Environmental Planning 2011

Este trabalho avaliou o desempenho ambiental do biodiesel obtido de óleo de girassol e metanol, através da Avaliação do Ciclo de Vida (ACV), mediante identificação e quantificação da energia e materiais consumidos, e das emissões ao longo do ciclo de vida, com o objetivo de analisar os impactos sobre o ambiente e avaliar as possibilidades de melhoria. Adicionalmente, foram comparados os resultados obtidos para o biodiesel com os do ciclo de vida do óleo diesel, ambos desempenhando a mesma função de combustível para motores diesel. Neste estudo, foram analisadas cinco categorias de impacto que representaram as principais ações da produção e uso do óleo diesel e biodiesel no ambiente: acidificação, aquecimento global, eutrofização, uso de energia não-renovável e oxidação fotoquímica. O que se pôde observar, dentro do escopo desse estudo, é que o biodiesel, em comparação com o óleo diesel, reduz o uso de energia não-renovável e aquecimento global. Por outro lado, o uso do biodiesel aumenta os impactos da acidificação e eutrofização. Ainda, o uso do óleo diesel causa mais impacto relativamente à oxidação fotoquímica, embora as emissões do uso do biodiesel também sejam relevantes. Considerando-se os escores normalizados, o maior impacto do biodiesel é a acidificação (45,5%), seguido da eutrofização (24,6%), aquecimento global (12,9%), energia não-renovável (12,9%) e oxidação fotoquímica (4,1%). O maior impacto do diesel é o aquecimento global (43,8%), seguido da energia não-renovável (43,4%), oxidação fotoquímica (9,0%), acidificação (3,5%) e eutrofização (0,3%). Observouse também que a obtenção da matéria-prima óleo vegetal e a combustão são as etapas dentro do ciclo de vida do biodiesel com maior impacto, dentre as categorias selecionadas. Isso torna as técnicas agrícolas de plantio e manejo de fertilizantes, bem como a eficiência de motores ciclo diesel, fatores cruciais para o desempenho como um todo do biodiesel. Uma cuidadosa atenção a estas etapas é altamente relevante para que o biodiesel seja considerado contribuinte das soluções mitigadoras da alteração do clima e da poluição antrópica. / This study evaluated the environmental performance of biodiesel from sunflower oil and methanol through the Life Cycle Assessment (LCA), through identification and quantification of energy, material consumption, and emissions throughout the life cycle. The objective of this work was analysis of environmental impacts, along with the assessment of process improvements. Additionally, results obtained for biodiesel were compared with those of the life cycle of diesel, both performing the same function as fuel for diesel engines. In this study, five environmental impact categories representing environmental burdens, in the production chain and use of diesel and biodiesel, were analysed: acidification, global warming, eutrophication, use of non-renewable energy and photochemical oxidation. A reduction of the use of non-renewable energy and global warming was observed when comparing biodiesel with diesel fuels. On the other hand, the use of biodiesel increases acidification and eutrophication. Yet, the use of diesel fuel causes more impact related to photochemical oxidation, although emissions are also relevant, when biodiesel is utilised. Considering the normalized scores, the largest impact of biodiesel is the acidification (45.5%), followed by eutrophication (24.6%), global warming (12.9%), non-renewable energy (12.9%) and photochemical oxidation (4.1%). The largest impact of the diesel is global warming (43.8%) followed by non-renewable energy (43.4%), photochemical oxidation (9.0%), acidification (3.5%) and eutrophication (0.3%). It was also observed that the processes of sunflower seeds production and fuel combustion are the steps in the life cycle of biodiesel with the largest impact among the selected processes. As a consequence planting and fertilizer management, and the efficiency of diesel engine are crucial factors to the overall performance of biodiesel. A careful attention should be given to these stages in order to have a biodiesel that can be considered as a solution to climate change and anthropogenic pollution.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Zifei Liu / The Unmix and Positive Matrix Factorization (PMF) models for source apportionment were applied to evaluate prescribed burning impacts on air quality, identify model advantages, and establish a relationship between visibility and PM₂.₅ sources. Speciated PM₂.₅ data were from the Flint Hills (FH) rural and the Kansas City (KC) urban sites. At the FH site, the Unmix model identified five sources: nitrate/agricultural, sulfate/industrial, crustal/soil, smoke, and secondary organic aerosol (SOA); while the PMF model identified the copper source in addition. The smoke source from PMF result includes both primary and secondary aerosols from prescribed burning when the smoke source in Unmix result only includes primary burning aerosols. The secondary smoke aerosols at the FH site were combined with secondary aerosols from other origins and formed the SOA source in Unmix result. Comparative analysis of the modeling results estimated the SOA to be 2.3 to 2.7 times of the primary aerosols in burning season. At the KC site, both receptor models derived seven-source solutions: nitrate/agricultural, sulfate/industrial, crustal/soil, smoke, traffic/SOA, heavy-duty diesel vehicle (HDDV), and calcium. The smoke source at the KC site carries an exceedingly organic carbon to elemental carbon (OC/EC) ratio, which is more than five times higher than in FH smoke source. The PMF results at KC site tend to classify more SOA from nitrate/agricultural and sulfate/industrial sources into traffic/SOA source. In the burning season, the smoke source from both sites showed a relatively high correlation when KC is under west and southwest wind, suggesting that part of the smoke originated PM₂.₅ at the urban site could be from the upwind burning activities. The Tobit modeling recognized the nitrate/agricultural as the leading visibility degradation impact factor at both sites. The latter chapter conducted a review of life cycle assessment (LCA) on carbon footprint (CF) of beef production. The objectives were to evaluate CF range in raising systems from different countries, identify the leading CF contributor and dominant source of uncertainty, and summarize LCA inventory defined in cattle production systems. Most existing beef LCA studies followed a “cradle to farm gate” approach. The CF in 3-phase systems ranged from 16 to 29.5 kg CO2e kg⁻¹ carcass weight. The 2-phase raising system reported a slightly lower CF than the 3-phase system (18.9 to 26.9 kg CO2e kg⁻¹ carcass weight), but no significant differences were observed. The grass-fed system in the US has the highest CF, but the CF of grass-fed systems in the European Union (EU) is 40% less than them in the US. This is because more than half of cattle farms in EU produce both beef and milk, and the CF burden was partaken by the dairy production. Cow-calf phase contributed the most CF in 3-phase raising system, while enteric fermentation was the major contributor. Feed production contributed the most in the feedlot phase if forages were applied rather than concentrates. The leading uncertainty sources reported was land use change and disparate dressing percentage. To improve the LCA accuracy, more research is needed in collecting reliable LCA inventory data such as raising period and feed intake efficiency.

abstract: Ecolabels are the main driving force of consumer knowledge in the realm of sustainable product purchasing. While ecolabels strive to improve consumer's purchasing decisions, they have overwhelmed the market, leaving consumers confused and distrustful of what each label means. This study attempts to validate and understand environmental concerns commonly found in ecolabel criteria and the implications they have within the life cycle of a product. A life cycle assessment (LCA) case study of cosmetic products is used in comparison with current ecolabel program criteria to assess whether or not ecolabels are effectively driving environmental improvements in high impact areas throughout the life cycle of a product. Focus is placed on determining the general issues addressed by ecolabelling criteria and how these issues relate to hotspots derived through a practiced scientific methodology. Through this analysis, it was determined that a majority the top performing supply chain environmental impacts are covered, in some fashion, within ecolabelling criteria, but some, such as agricultural land occupation, are covered to a lesser extent or not at all. Additional criteria are suggested to fill the gaps found in ecolabelling programs and better address the environmental impacts most pertinent to the supply chain. Ecolabels have also been found to have a broader coverage then what can currently be addressed using LCA. The results of this analysis have led to a set of recommendations for furthering the integration between ecolabels and life cycle tools. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2012

The aim of this case study has been to evaluate differences between the public and the private sector based on interest and knowledge of Life cycle assessments, LCA, of residential buildings. The construction and building sector have a major impact on the environment and the climate change. Methods and tools are required to measure and compare the environmental impacts generated from human activities and products within the sector. The entire life cycle must be known and kept in mind in order to value the total environmental impact of activities and products. The environmental life cycle of a product consists all the different stages, from raw material, through use, to waste management. Life cycle assessment is a method that makes it possible to value and then minimize the environmental impact throughout the whole life cycle. Telephone interviews with representatives from participant counties and companies have been made in order to compare their answers and to achieve great insight of how they work towards environmental questions. The results show that the sectors differ from each other. The private sector was further in the development, although a larger number of the counties had plans on using the assessment in the future. The interviews indicated LCA’s future role in the sector, and even though LCA’s is quite new in the area the future seems bright. The global population and the demand for residents are continuously increasing and the need to adopt the sector to sustainable development is substantial.

Este trabalho avaliou o desempenho ambiental do biodiesel obtido de óleo de girassol e metanol, através da Avaliação do Ciclo de Vida (ACV), mediante identificação e quantificação da energia e materiais consumidos, e das emissões ao longo do ciclo de vida, com o objetivo de analisar os impactos sobre o ambiente e avaliar as possibilidades de melhoria. Adicionalmente, foram comparados os resultados obtidos para o biodiesel com os do ciclo de vida do óleo diesel, ambos desempenhando a mesma função de combustível para motores diesel. Neste estudo, foram analisadas cinco categorias de impacto que representaram as principais ações da produção e uso do óleo diesel e biodiesel no ambiente: acidificação, aquecimento global, eutrofização, uso de energia não-renovável e oxidação fotoquímica. O que se pôde observar, dentro do escopo desse estudo, é que o biodiesel, em comparação com o óleo diesel, reduz o uso de energia não-renovável e aquecimento global. Por outro lado, o uso do biodiesel aumenta os impactos da acidificação e eutrofização. Ainda, o uso do óleo diesel causa mais impacto relativamente à oxidação fotoquímica, embora as emissões do uso do biodiesel também sejam relevantes. Considerando-se os escores normalizados, o maior impacto do biodiesel é a acidificação (45,5%), seguido da eutrofização (24,6%), aquecimento global (12,9%), energia não-renovável (12,9%) e oxidação fotoquímica (4,1%). O maior impacto do diesel é o aquecimento global (43,8%), seguido da energia não-renovável (43,4%), oxidação fotoquímica (9,0%), acidificação (3,5%) e eutrofização (0,3%). Observouse também que a obtenção da matéria-prima óleo vegetal e a combustão são as etapas dentro do ciclo de vida do biodiesel com maior impacto, dentre as categorias selecionadas. Isso torna as técnicas agrícolas de plantio e manejo de fertilizantes, bem como a eficiência de motores ciclo diesel, fatores cruciais para o desempenho como um todo do biodiesel. Uma cuidadosa atenção a estas etapas é altamente relevante para que o biodiesel seja considerado contribuinte das soluções mitigadoras da alteração do clima e da poluição antrópica. / This study evaluated the environmental performance of biodiesel from sunflower oil and methanol through the Life Cycle Assessment (LCA), through identification and quantification of energy, material consumption, and emissions throughout the life cycle. The objective of this work was analysis of environmental impacts, along with the assessment of process improvements. Additionally, results obtained for biodiesel were compared with those of the life cycle of diesel, both performing the same function as fuel for diesel engines. In this study, five environmental impact categories representing environmental burdens, in the production chain and use of diesel and biodiesel, were analysed: acidification, global warming, eutrophication, use of non-renewable energy and photochemical oxidation. A reduction of the use of non-renewable energy and global warming was observed when comparing biodiesel with diesel fuels. On the other hand, the use of biodiesel increases acidification and eutrophication. Yet, the use of diesel fuel causes more impact related to photochemical oxidation, although emissions are also relevant, when biodiesel is utilised. Considering the normalized scores, the largest impact of biodiesel is the acidification (45.5%), followed by eutrophication (24.6%), global warming (12.9%), non-renewable energy (12.9%) and photochemical oxidation (4.1%). The largest impact of the diesel is global warming (43.8%) followed by non-renewable energy (43.4%), photochemical oxidation (9.0%), acidification (3.5%) and eutrophication (0.3%). It was also observed that the processes of sunflower seeds production and fuel combustion are the steps in the life cycle of biodiesel with the largest impact among the selected processes. As a consequence planting and fertilizer management, and the efficiency of diesel engine are crucial factors to the overall performance of biodiesel. A careful attention should be given to these stages in order to have a biodiesel that can be considered as a solution to climate change and anthropogenic pollution.

Climate change may have detrimental effects on agriculture productivity (Challinor et al., 2009). At the same time, agriculture also plays a role in contributing to the causes of global warming (IPCC, 2009). The present research examined current agro-management practices of select agriculture management practices and products with a threefold objective, namely i) to understand the possible impact of climate change on crop yields, ii) to examine the carbon sequestration potential of select agricultural crops and management practices, and iii) to conduct a thorough life cycle assessment to estimate the carbon footprint of select agriculture crops and management practices, so as to help policy makers, planners and business managers in devising appropriate mitigation and adaptation policy frameworks and make sensible management decisions in the context of climate change. The research was conducted in a series of three studies. The first study investigated future corn and soybean yields in the Raccoon watershed in the US Corn Belt using projected climate data. This study used the Environment Policy Integrated Climate (EPIC) model to estimate the impact of climate change for 2015-2099 with data downscaled from eight atmosphere-ocean general circulation models (AOGCMs) with three emissions pathways reflecting low, medium and high greenhouse gas scenarios. Soil properties were gathered from the Soil Survey Geographic Database and data on crop rotation was derived from CropScape, a geospatial cropland data layer product of the US National Agricultural Statistics Service. Our findings show that 5-year averages of both corn and soybean yields for 2095-2099 depicted by all eight AOGCMs under low and medium carbon scenarios will increase in comparison to the 5-year average yields for 2015-2019. However, under the high carbon scenario, 5-year averages of both corn and soybean yields for 2095-2099 will decline in comparison to the 5-year average yields for 2015-2019 pointing to the effects of climate change. The study also examined the possible impact of carbon fertilization on yields. The results show that carbon fertilization of soybean, a C3 plant, may contribute to an increase in yield of 3% to 22% while its contribution to the growth of corn, a C4 plant, will be much lower. The second study focused on land-based carbon sequestration possibilities. Land-based carbon sequestration constitutes a major low cost and immediately viable option in climate change mitigation. Using downscaled data from eight atmosphere-ocean general circulation models for a simulation period between 2015 and 2099, the study examined the carbon sequestration potential of alternative agricultural land uses in an intensively farmed Corn Belt watershed and the impact of climate change on crop yields including impact on switchgrass. The results of the study show that switching from conventional tillage and continuous corn to no-till corn-soybean can sequester the equivalent of 192.1 MtCO2 eq of soil organic carbon per hectare with a sequestration rate of 2.26 MtCO2 eq ha-1 yr-1. The results also indicate that switchgrass can sequester the equivalent of 310.7 MtCO2 eq of soil organic carbon per hectare with a sequestration rate of 3.65 MtCO2 eq ha-1 yr-1. The findings of this research suggest that climate change does not have a significant effect on switchgrass yields, unlike on corn and soybean yields, possibly due to the carbon fertilization effect. As mentioned, agriculture can contribute to climate change mitigation efforts by providing low–land-based options through changes in agricultural management practices. A thorough life cycle assessment is necessary to compare various opportunities provided by a variety of agricultural approaches. The last study is a cradle-to-farm gate life cycle assessment of the contributions of select agricultural practices to mitigate global warming. The study focused on land-based practices including crop rotations instead of just individual crops. In the assessment, the study also included examinations of below-the-ground soil to determine the organic carbon sequestration potential of such practices, which most of the time is ignored in life cycle assessments due to lack of data. Specifically, the study examined three farming practices in the intensively farmed Raccoon watershed: continuous corn rotation with conventional tillage, corn-soybean rotation with no-till, and switchgrass. The assessment was conducted based on land units (hectares), instead of utilizing the usual practice of reporting life cycle assessment in product units, such as kilograms. The results of the life cycle assessment reveal that among the three agricultural practices, switchgrass has the lowest carbon footprint overall, and continuous corn rotation has the highest. Switching from continuous corn to switchgrass would reduce the overall greenhouse gases the most, by 6.30 Mg CO2eq/ha/yr, or by 62% compared to the emissions generated by the continuous corn rotation. Similarly, planting switchgrass instead of a corn-soybean rotation would reduce the overall emissions of greenhouse gases by 1.84 Mg CO2eq/ha/yr, or by 32% compared to the corn-soybean rotation. Finally, switching from continuous corn to the corn-soybean rotation would reduce overall greenhouse gases emissions by 4.46 Mg CO2eq/ha/yr or by 44% of the emissions generated by continuous corn. These findings can inform policy discussions on the potential of agriculture’s role in climate change mitigation.

Searching for environmentally sustainable alternatives for reinforcement of composite materials, flax fibre has one of the most promising potentials due to its desired mechanical properties. The fact that flax is a bio-material, in contrast to conventional synthetic fibres, does not ensure a less environmental impact. One of the major source of environmental impact related to flax fibre as a reinforcement material is the cultivation of flax fibre. In this study the environmental impact of flax fibre cultivation was studied by performing an environmental impact analysis with a life cycle assessment inspired approach.  The result showed that the quantification of the environmental impacts varied to a large extent depending on several parameters such as allocation method and whether carbon sequestration was included in the calculations. One striking example is the results for global warming potential, ranging from 10 000 kg CO2-equivivalents to a negative value per 1 tonne of flax fibre. The study showed the production and use of fertilizers to be the major contribution to the environmental impact by as much as 70-90 %. In order to limit the environmental impact from flax fibre cultivation suggested environmental improvements are to optimise the fertiliser use according to the flax type and soil conditions, improving nitrogen fixation as well as using organic fertilizers. / <p>2018-06-27</p>