<p>The building sector is a major contributor to theenvironmental loads generated by the society. The recognitionof this fact by the sector and a general strive toward asustainable society have lead to afocus on different toolsthat can be used to enhance the environmental performance ofthe sector and the society. Life Cycle Assessment (LCA) is oneof these tools. The LCA methodology was initially developed forassessments of short-lived consumer products. The increasinginterest in using the LCA methodology in the context of thebuilding sector has initiated a development of the methodologyto be able to consider the specific characteristics andconsiderations of the building sector. These are specific forthe building sector, but not always unique. Examples ofcharacteristics and considerations are: that each building isunique, the functional output is not always a physical productbut rather a service, the long service lives of buildings.These have implications on several elements in the LCAmethodology. The influenced elements that are dealt with inthis thesis are in particular the modeling of the system, thefunctional unit, boundary setting, life cycle scenarios,scenarios and inventory of the usage phase and allocationprocedures.</p><p>Buildings and constructions are commonly not static systems.The systems are rather dynamic in the sense that the systemwill provide different services based on the same physicalstructure during its service life. To be able to model thedynamic system sequential life cycle thinking is introduced anda list of topics is derived. The list of topics is a structuredpresentation of issues that are of interest in the pursuit of aflexible LCA methodology. The goal is to find out if amethodological approach is suitable for modeling dynamicsystems with a functional unit that is based on the providedservice rather than the physical building.</p><p>Boundary setting, life cycle scenarios, allocationprocedures, predicted service life and the modelling of theusage phase are all elements of the LCA methodology that havean potential to influence the result of an LCA in a significantway. The magnitude of the potential influence has beenmonitored based on the results of three case studies, whichhave been elaborated further to be able to estimate themagnitude of the potential influence.</p><p>There is a multitude of available allocation procedurespresented and used in different contexts. The procedures aredeveloped based on different considerations and with differentintended applications. Two alternative allocation proceduresare presented in this thesis. The first is a proceduredeveloped with multi recyclable materials in mind and it isbased on the recyclability of materials and products. Thesecond procedure is quite recently developed and it is based ona combination of economic parameters and recyclability.</p><p>The importance of the usage phase for buildings andconstructions has previously been recognised. The maincontributors to the environmental loads generated during theusage phase are energy use, maintenance and emissions fromproducts. It is, however, not very common to consider the usagephase in assessments conducted on materials and components,even though it is stipulated in e.g. ISO 14025 that the wholelife cycle should be considered. A proposal of a model toestimate the environmental loads is, therefore, presented.</p><p><b>Keywords:</b>Life cycle assessment, Building materials andcomponents, Buildings and constructions, Allocation, Resultvariation, Usage phase, Energy demand</p>

As demand for electricity increases, utilities turn to demand-side or supply-side responses in order to reduce demand or add supply to their energy portfolio. CPS Energy, a municipal utility owned by the City of San Antonio, Texas, recently broke ground on a new coal plant to meet rising demand for electricity. This report examines the public debate that accompanied the proposal and investigates the possibilities of other solutions for utilities to meet demand. Two case studies, overviews of the utilities in Austin, Texas, and Sacramento, California, provide insight into the considerations for utilities with renewable energy and demand-side management (DSM) in their energy portfolio. This professional report will evaluate these case studies and apply lessons learned to the case of CPS Energy in San Antonio, and report on the options available to utilities considering conventional supply-side additions and demand-side management. / text

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>

Šio darbo tikslas - ištirti aplinką tausojančių atsinaujinančių saulės ir vėjo energijos konversijos sistemų galimybes tenkinti pastatų kaimo vietovėse šilumos poreikius ir pagrįsti šių sistemų optimalius parametrus. Atsižvelgiant į planetos gamtos išteklių ribotumą ir siekiant užtikrinti aukštą aplinkosaugos lygį, skatinamas tvarus vartojimas ir gamyba. Vartojant mažiau energijos ir daugiau atsinaujinančių išteklių energijos galima padidinti energijos tiekimo garantijas bei sumažinti aplinkos taršą. Lietuvos gyvenamuosiuose būstuose per metus sunaudojama apie 55 - 57 PJ kuro ir energijos, iš kurių apie 25 - 27 PJ sunaudojama šilumos reikmėms. Vienbučiuose kaimo namuose šilumos reikmėms tenkinti naudojamos krosnys ir autonominiai kieto kuro katilai, kurui naudojantys malkas bei medienos atliekas. Kurą naudojant neefektyviai, degimo metu neišvengiama kenksmingų teršalų patekimo į aplinką. Šilumos reikmėms naudojant atsinaujinančių šaltinių energijos konversijos sistemas galima sumažinant aplinkai kenksmingų teršalų emisijas vartojant mažau kuro. Aplinką tausojančių saulės ir vėjo energijos konversijos sistemų naudojimo galimybės priklauso nuo šių energijos šaltinių potencialo ir energijos konversijos sistemų efektyvumo. Analizuojant daugiamečius saulės spindulinės energijos ir vėjo energijos potencialo tarpusavio sąveikos ir kitimo dėsningumus nustatyta, kad šias atsinaujinančios energijos rūšis pastatų šilumos reikmėms tenkinti tikslinga naudoti kompleksiškai, energijos... [toliau žr. visą tekstą] / The research work aim is to investigate the possibilities to use solar and wind energy conversion systems for answering of the thermal needs of the dwelling houses in rural areas and to substantiate the optimum parameters of these systems. The sustainable consumption and production is encouraged having in mind limited natural resources of the planet and actuated sustainable consumption and manufacturing. Less power consumption and greater application of renewable energy sources enable to increase the energy supply guarantees and minimize the ambient pollution. Approximately 55 – 57 PJ of the fuel and power have been used in the dwelling houses in Lithuania. About 25 – 27 PJ has been used for thermal needs. Firewood and wood residues are burned in furnaces of individual houses in rural areas. When the fuel is used inefficiently hazardous contaminants pollute the environment. When the energy conversion systems of renewable sources are used for thermal needs the emissions of harmful contaminants into the atmosphere can be greatly minimized because of the less fuel consumption. Possibility to use solar and wind energy conversion systems benevolent to the environment depends on the potential of these energy sources and the efficiency of these energy conversion systems. The analyses of the interaction of potential of solar radiant energy and wind energy during the decade and the change of its consistent pattern disclosed that these types of renewable energy used for thermal needs... [to full text]

The first part of the graduation thesis deals with renewable resources, utilization possibilities of biomass and plant phytomass. The most common sources from which phytomass is obtained, are also mentioned here. A great deal of attention is paid to selected energetic plants included into the experiment. It is Sorrel Rumex OK-2 (Rumex tianschanicus x Rumex patientia) and Poppy seed (Papaver Somniferum). Further there are summarized the processes necessary for separating and pressing of biomass into granules for direct combustion. Within the research, two-year experience of growing sorrel stand is described. On the basis of performed technological operations in the stand, energy demands of growing are calculated. The real usage of energy at the production of one tonne of granules is measured. When labour costs are taken into account I can say that the expenses for the production of one tonne of briquettes from biomass would be 4 592 CZK, which is a non-competitive sum.

Nous nous intéressons au traitement tertiaire d'eaux issues de stations d'épuration traitant des eaux usées domestiques, en vue de leur réutilisation en particulier pour l'irrigation. Les opérations de séparation membranaires sont aujourd'hui les plus souvent considérées pour ce type de traitement, avec par exemple l'osmose inverse couplée à de l'ultrafiltration en pré traitement. Ces solutions présentent les inconvénients propres à ces technologies, inconvénients qui restent à lever au plan scientifique mais aussi au plan technologique. Notre objectif initial était de reconstruire totalement le schéma de procédé de réutilisation des eaux, à partir de son analyse globale. Nous avons pu réaliser seulement trois des étapes de ce travail : L'analyse de l'efficacité de techniques de modification de surface de membranes d'ultrafiltration en vue de rendre le colmatage réversible. L'analyse de la faisabilité d'utiliser la distillation membranaire pour traiter des eaux usées en sortie de station d'épuration traditionnelles ou par bio réacteurs à membranes, dont nous avons fait une évaluation expérimentale à partir d'eaux de complexité croissante, allant jusqu'au traitement d'eaux prélevées directement en sortie de station. Les résultats prometteurs de ces essais ont été complété par une recherche de points de fonctionnement de la distillation membranaire, par une analyse classique de bilans matière et d'énergie, dont l'originalité est la prise en compte du facteur de conversion comme paramètre opératoire. / We are interested in polishing steps of waters from sewage treatment plants dealing with domestic wastewater, with a view to their re-use, in particular for irrigation. Membrane separation operations are today most often considered for this type of treatment, with, for example, reverse osmosis coupled with ultrafiltration as a pretreatment. These options present the disadvantages peculiar to these technologies, disadvantages which still need to be sorted out scientifically but also at the technological level. Our initial objective was to completely reconstruct the water reuse flow sheet, based on its overall analysis. We were able to achieve only three of the stages of this work: Analysis of the efficiency of surface modification techniques of ultrafiltration membranes in order to make them fouling resistant. The analysis of the feasibility of using membrane distillation to treat wastewater discharged from traditional sewage treatment plants or by bio-membrane reactors, of which we have made an experimental evaluation based on waters of increasing complexity, up to the treatment of water taken directly from the treatment plant. The promising results of these tests lead us to define operating points for membrane distillation, by a classical analysis of material and energy balances, in which the stage cut-off was considered as an operational parameter.

Gävle Energi har nyligen implementerat en ny prismodell till fjärrvärmen med en säsongsprismodell som kom 2018 och en kapacitetsprismodell som kommer 2019. Den nya prismodellen ska återspegla kostnaden för att producera fjärrvärmen samt belöna kunder som utför effektiviseringsåtgärder. Kapacitetsprismodellen, som denna studie fokuserar på, kommer att baseras på anläggningens energibehov vid -10 grader. Då kapacitetspriset är samma för samtliga kunder så kommer priset kunden betalar att återspegla hur stort energibehov byggnaden har vid -10 grader. I denna studie har det undersökts om en uppskattning kan utföras för att ta reda på hur stort energibehov en nyansluten kunds byggnad behöver vid -10 grader utifrån tidigare anslutna kunder. Signaturer för 115 tidigare anslutna kunder med byggnader byggda från 2000 – 2018 användes vid denna studie. Byggnaderna kategoriserades för att kunna jämföra energibehovet för varje kund med en liknande byggnad. Utifrån detta skapades uppvärmningssignaturer för varje enskild byggnad, vilka sammanställdes i diagram uppdelade på varje byggnadskategori. Med detta var tanken att en standardsignatur kunde skapas för varje kategori för att sedan kunna använda denna signatur vid kapacitetsberäkning av en ny kunds byggnad. Då resultatet inte blev som tänkt kunde dessa standardsignaturer dock inte skapas, utan en djupare analys för varje byggnad ser ut att behöva utföras. Hade en standardsignatur skapats utifrån befintliga resultat hade ett felaktigt energibehov tilldelats kunder med hög respektive låg energianvändning. Två olika metoder användes för att beräkna energibehovet bakom uppvärmningssignaturerna, dels med boarean för byggnaderna, dels med omslutande arean då tanken var att den omslutande arean skulle ge ett bättre resultat. Användningen av den omslutande arean vid framtagandet av signaturerna visade sig dock inte vara av bättre användning då resultaten varierade för mycket. / Gävle Energi have recently implemented a new price model for district heating with a seasonal depended price model that came in 2018 and a capacity pricing model that will be implemented 2019. The new price model is supposed to reflect the cost to produce the district heating and to reward customers who preform efficiency measures to their buildings. The capacity pricing model, on which this study is focused on, will be based on the buildings energy demand at -10 degrees. Since the capacity price is the same for all customers, the price the customer pays instead will reflect the amount of energy demand the building needs at -10 degrees. In this study it will be investigated whether an estimate can be made to find out how big of an energy demand a newly connected customer’s building needs at -10 degrees from previously connected customers. Signatures from 115 previously connected customers with buildings build from 2000 – 2018 were used in this study. The building was then categorized to compare the energy demand for each customer with a similar building. Based on this, signatures were created for each individual building and then put together in a common chart for each category. With this, the idea was that a standard signature could be created for each category to the use this signature when calculating the capacity for a customer’s building. As the result was not as intended, these standard signatures could not be created without preforming a deeper analysis of each building. If a standard signature had been created with these results, an unfair capacity had been awarded to customers with a high and low energy consumption. Different analyzes were used to calculate the different energy demands for the creation of the signatures, partly with the housing area of the buildings and the surrounding area with the thoughts that the surrounding area would provide the study with a better result. However, the use of the surrounding area in the development of the signatures did not provide to be of better use as the results varied too much.

A conservação de energia, mais precisamente a eficiência energética, vem ganhando importância nos últimos anos no Brasil e no mundo em função dos impactos ambientais que o uso intensivo de energia gera ao meio ambiente e pelo fato de a oferta de energia, principalmente as derivadas de fontes não renováveis, estar se tornando cada vez mais escassa. Estudos que abordam os impactos que os ganhos de eficiência podem gerar em termos de custos e na conservação de energia e, por conseguinte, na diminuição dos efeitos da atividade industrial no meio ambiente vem ganhando importância. Este trabalho teve como motivação principal determinar o impacto da Eficiência Energética na demanda de energia da indústria brasileira. Para isso utilizaram-se duas metodologias complementares para dissertar a respeito do tema. Primeiramente, a intensidade energética foi decomposta em dois efeitos distintos, Efeito Intensidade e Efeito Estrutural. Os resultados encontrados sugerem que o Efeito Intensidade foi o principal responsável pela perda de Eficiência no consumo de energia pela indústria. Como o Efeito Intensidade é uma importante proxy para a Eficiência Energética, buscou-se determinar o impacto desta no consumo de energia pela industria brasileira. Outras variáveis também foram utilizadas para compor a função de demanda de energia, como PIB industrial, preços médios ponderados das diferentes fontes de energia e o nível de salários pagos na indústria. Os resultados encontrados sugerem que um aumento de 1% no Efeito Intensidade tem impacto de 0,297% no consumo de energia industrial. Procurou-se também neste trabalho buscar os determinantes da Eficiência Energética. Para tal, utilizou-se como variáveis explicativas a Formação Liquida de Capital Fixo como proxy dos investimento feitos pela indústria, a Utilização da Capacidade Instalada como um indicador de excesso ou de subutilização do parque industrial e por fim a Taxa de Câmbio Real, dado que a maior parte dos setores energo-intensivos industriais também se caracterizam pela forte abertura ao comércio exterior. Os resultados encontrados sugerem que o aumento na Utilização da Capacidade Instalada implica na perda de Eficiência Energética. Por outro lado, aumento na Formação Liquida de Capital Fixo contribui para a redução do Efeito Intensidade que implica aumento na utilização eficiente de energia. Concluiu-se que o aumento da Taxa de Investimento na economia, além de aumentar a Eficiência Energética na indústria, também é responsável por reduzir o consumo de energia e assim beneficiar o próprio setor industrial através da redução de custos como também toda a sociedade através dos benefícios que a redução da produção de energia pode gerar no meio ambiente e na poupança de recursos não renováveis. / The conservation of energy, specifically energy efficiency is gaining importance lately in Brazil and the world due environmental impacts that intensive use of energy generates to the environment and for the fact that the supply of energy, mainly derived from nonrenewable sources, is becoming increasingly scarce. Studies which approach the impacts that efficiency gains can generate in terms of cost and energy conservation and, therefore, to reduce the effects of industrial activity on the environment are gaining importance. This work had as its main motivation to determine the impact of energy efficiency in energy demand of Brazilian industry. For this we used two complementary methodologies to discourse on the subject. First, the energy intensity was decomposed into two distinct effects: Intensity effect and Structural effect. The results suggest that the Intensity effect was mainly responsible for the loss of efficiency in energy used by industry. As the Intensity Effect is an important proxy for the Energy Efficiency, we attempted to determine the impact of energy consumption in Brazilian industry. Other variables were also used to compose the function of energy demand, such as industrial GDP, weighted average prices of different energy sources and the level of salaries paid in the industry. The results suggest that a 1% increase in the intensity effect has an impact of 0.297% in industrial energy consumption. We also sought to pursue the determinants of Energy Efficiency. For this purpose, we used as explanatory variables the Net Fixed Capital Formation as a proxy of the investment made by the industry, the Use of Installed Capacity as an indicator of excess or industrial underused and finally the Real Exchange Rate, as most energy-intensive industrial sectors are also characterized by a strong opening to foreign trade. The results suggest that increased use of installed capacity implies the loss of energy efficiency. On the other hand, increase in Net Fixed Capital Formation contributes to the reduction of the Intensity Effect which implies an increase in the efficient use of energy. It was concluded that the increased Rate of Investment in the economy, besides increasing the Energy Efficiency in industry, is also responsible for reducing energy consumption and thus benefit the industrial sector itself by reducing costs as well as the whole society through the benefits that the reduction of energy production can have on the environment and saving non-renewable resources.

A cana-de-açúcar é a cultura com finalidade energética mais importante do agronegócio brasileiro, por gerar muitos empregos no setor, representar uma parcela significativa do PIB agropecuário e por ser a fonte renovável de energia com maior participação na matriz energética brasileira. O sucesso de seu cultivo depende, dentre outros fatores, da realização do preparo de solo adequado para fornecer às plantas condições favoráveis de desenvolvimento, particularmente do sistema radicular. Em geral, ele é realizado a cada cinco anos e o custo de implantação do canavial, no qual ele se inclui, é alto, representando em torno de 25% desse custo. Os sistemas de preparo de solo comumente utilizados são o convencional e o reduzido, ambos mecanizados. O primeiro tem como característica práticas intensivas de mobilização do solo em camadas mais rasas, enquanto o segundo é composto por número reduzido de operações e máquinas na área e a mobilização do solo pode ser em camadas rasas ou profundas. A escolha pelo sistema de preparo de solo mais econômico e sustentável é complexa por envolver muitas variáveis. Avaliações econômica e energética têm sido uma alternativa eficiente para analisar sistemas de produção agrícola, pois fornecem indicadores financeiros e ambientais para auxiliar na tomada de decisão na adoção do sistema de preparo. Tendo em vista a importância econômica e energética da cana no cenário nacional, a influência do preparo de solo no desenvolvimento da planta e na composição dos custos operacionais, associados à carência de estudos energéticos que avaliem o sistema mecanizado do preparo profundo do solo, este trabalho teve o objetivo de analisar a viabilidade econômica e energética do sistema de preparo de solo profundo no cultivo da cana-de-açúcar em comparação ao sistema convencional. Para tal foi desenvolvido um modelo em planilha eletrônica que auxiliou na determinação dos indicadores econômicos e energéticos de cada sistema de preparo de solo. Os resultados apontaram que o sistema de preparo profundo do solo é viável do ponto de vista econômico e energético, pois apresentou custo operacional de 401,50 R$ ha-1 e demanda de energia de 2,63 GJ ha-1, respectivamente, 30% e 40% inferiores, ao sistema convencional. A análise de sensibilidade evidenciou que a capacidade de campo operacional, a potência do trator e o consumo de combustível foram os fatores de maior impacto na variação dos custos operacionais e na demanda de energia de entrada. / Sugarcane is the most of important energy crop for Brazilian agribusiness, since it propitiates many jobs, it represents a significant share of agricultural GDP and it is the renewable source of energy of higher contribution to the energy matrix. The success of its cropping depends, among other factors, of the appropriate tillage system to provide the plants favorable development conditions, particularly to the root system. Generally, it is carried out on every five years and it accounts around 25% of cropping cost. Soil tillage systems usually adopted are conventional and reduced, both mechanized. The conventional system consists of several operations in the superficial layers, while the reduced one uses less operations and soil mobilization can be in shallow or deep layers. In this latter category, the system of deep soil tillage is included if it is carried out in rows of planting. Economic and sustainable soil preparation system is complex because it involves many variables. Economic and energy assessments have been an efficient alternative to analyze agricultural production systems because it provides financial and environmental indicators for decision making on system adoption. Considering the economic and energy importance of sugarcane in the national scenario, the influence of soil preparation on the development of the plant and the composition of the operational costs, associated to the lack of energy studies that evaluate the mechanized system of deep soil preparation, this study aimed to analyze the economic and energy viability of the deep soil preparation system in sugarcane cultivation compared to the conventional system. For this purpose, a model was developed which assisted in the determination of the economic and energy indicators of each soil preparation system. The results showed that the deep soil preparation system is feasible from an economic and energy point of view, since it presented operational cost of 401.50 R$ ha-1 and energy demand of 2.63 GJ ha-1, respectively, 30% and 40% below the conventional system. Sensitivity analysis showed that the operational field capacity, the power of the tractor, the fuel consumption were the factors presented greater relevance in the variation of operating costs and the demand for input energy.

Desde o primeiro choque do petróleo, em 1973, os países têm despendido esforços para reduzir sua dependência pelo produto, produzido principalmente em regiões politicamente instáveis. Os Estados Unidos são os maiores consumidores mundiais do combustível, e cerca de 70% são destinados ao transporte. Desde o final da década de 70, o governo americano tem incentivado o uso de etanol como substituto parcial da gasolina. No entanto, o crescimento do biocombustível levantou polêmicas porque a matéria-prima utilizada na sua produção no país é o milho, o que poderia estar afetando a oferta do grão para a produção de alimentos. Dessa forma, foi aprovado em 2007 o RFS2, uma legislação que prevê o consumo mandatório de volumes crescentes de etanol até 2022, mas limita a produção a partir de milho. Os investimentos em pesquisas de combustíveis alternativos passaram a se focar no desenvolvimento de etanol de segunda geração, que utiliza material celulósico como matéria-prima. Sua viabilidade técnica já foi confirmada, mas ainda são necessárias melhorias no processo de produção para que o produto possa ser ofertado em escala comercial. Por outro lado, o Brasil tem uma indústria de etanol madura e também tem feito pesquisas na tecnologia de segunda geração. Se bem sucedida, o país tem planos de exportar o excedente de produção, e os Estados Unidos são um mercado de interesse. O objetivo desta dissertação é auxiliar na avaliação das necessidades de os Estados Unidos importarem etanol de outros países, o que pode criar uma oportunidade para o Brasil. Para isso, foi utilizada a abordagem lógico-intuitiva de construção de cenários - voltada a aspectos qualitativos - para estudar o mercado de etanol combustível nos Estados Unidos até o ano de 2022. A coleta de informações foi feita por meio da revisão bibliográfica, focada em artigos internacionais. A política energética americana e a evolução da tecnologia de segunda geração de etanol foram identificadas como as principais incertezas que devem moldar o futuro do mercado em estudo. A partir delas, foram gerados quatro cenários, nomeados como \"Filho pródigo\", \"Pais esperançosos\", \"Filho independente\" e \"Filho preterido\". Concluiu-se que, enquanto o governo americano continuar incentivando o consumo de etanol, haverá boas oportunidades de exportação do biocombustível brasileiro. Os maiores volumes são esperados em \"Pais esperançosos\". Por outro lado, caso outras alternativas energéticas sejam priorizadas, nossas exportações podem reduzir substancialmente, e o volume comercializado dependerá do preço do nosso produto em relação ao deles e à gasolina. / Since the first oil shock in 1973, countries have made efforts to reduce their dependence on the product, mainly produced in politically unstable regions. The United States is the world\'s largest consumer of the fuel, and about 70 % is allocated to transport. Since the late 70s, the U.S. government has encouraged the use of ethanol as a partial substitute for gasoline. However, the growth of the biofuel arose controversy because the raw material used for the domestic production is corn, which could be affecting the supply of the grain for food production. Thus, it was approved in 2007 the RFS2, a legislation that requires mandatory use of increasing volumes of ethanol until 2022, but limits production from corn. Investments in alternative fuels research started to focus on the development of second generation ethanol, which uses cellulosic material as feedstock. Its technical feasibility has been confirmed, but improvements are still needed in the production process so that the product can be offered on a commercial scale. On the other hand, Brazil has a mature ethanol industry and is also doing research on second-generation technology. If successful, the country plans to export the surplus production, and the United States is a market of interest. The objective of this thesis is to assist the assessment of the United States needs to import ethanol from other countries, which may create an opportunity for Brazil. The logical-intuitive approach of scenario building - focused on qualitative aspects - was used to study the market for fuel ethanol in the United States until the year 2022. Data collection was done through literature review, focused on international articles. The U.S. energy policy and developments in the technology of second generation ethanol were identified as the major uncertainties that are shaping the future of the market under study. Four scenarios were generated from these two uncertainties and named as \"Prodigal Son\", \"Hopeful parents\", \"Independent Son\" and \"Deprecated Son\". It was concluded that while the U.S. government continues to encourage the consumption of ethanol, there are good opportunities to export the Brazilian biofuel. The largest volumes are expected in \"Hopeful parents\". On the other hand, if other energy alternatives are prioritized, our exports can reduce substantially, and sales volume will depend on the price of our product relative to theirs and gasoline.