O paradigma atual do uso da energia no setor industrial brasileiro é fruto da conjuntura histórica do setor energético no país e permite explicar algumas de suas características particulares, a utilização intensiva de eletricidade em processos térmicos, a eletrotermia, algo que perdura até hoje. O cenário nacional de produção de gás natural é promissor, no contexto do Pré-Sal, o que sinaliza uma oportunidade para aplicar esse recurso natural para usos energéticos com maior valor agregado, como por exemplo como energia final para a indústria. É neste contexto que se insere esta dissertação onde foi desenvolvida e aplicada uma técnica de análise de dados com objetivo de avaliar a inserção do gás natural no setor industrial brasileiro e seus impactos. A técnica de análise de dados desenvolvida constitui-se na avaliação de quatro indicadores: Demanda Adicional (DA); Impacto em Energia Primária (IEP); Impacto em Emissões de Carbono (IEC) e Impacto em Custo Energético (ICE). Nos resultados obtidos, o Setor de Metais Não-Ferrosos teve maior destaque ao apresentar a maior demanda adicional por gás natural e as maiores reduções em demanda de energia primária, emissões de CO2 e custo energético. Outros setores que se destacaram foram o Setor de Ferro e Aço e Setor de Alimentos e Bebidas. Tomando 2013 como ano-base, a demanda adicional por gás natural resultante da substituição de óleo combustível e eletricidade em processos térmicos representaria um aumento entre 37% a 42% na demanda de gás natural no setor industrial brasileiro, equivalente a 12% a 14% da oferta interna de gás natural no Brasil, ou ainda 35% a 40% da capacidade máxima do Gasbol. O impacto em energia primária representaria uma redução de 1% a 2% da demanda de energia primária do setor industrial brasileiro. O impacto em emissões de CO2 representaria uma redução de 4% a 5% das emissões de CO2 associadas ao uso de energia do setor industrial brasileiro. O impacto em custo energético representaria uma redução de 2% a 4% dos custos energéticos associados a eletricidade e óleo combustível do setor industrial brasileiro. Assim, considera-se que existe uma oportunidade de inserção do gás natural no setor industrial brasileiro resultante da substituição de óleo combustível e eletricidade por gás natural em processos térmicos. De forma geral, seus impactos reduzem a demanda de energia primária, as emissões de CO2 e o custo energético. Entretanto, trata-se de uma iniciativa de economia de energia via substituição energética, desse modo, ressalta-se necessidade de se fomentar a eficiência energética, para todos os usos finais e tipos de energia final em uso, de modo a se obter um maior impacto em termos de redução no consumo de energia e mitigação de emissões, dois elementos importantes no debate atual sobre combate a mudanças climáticas. / The present energy use structure in the Brazilian industrial sector is a consequence of its historical context within the Brazilian energy sector. This historical background helps to explain some characteristics, like the intensive use of electricity in heating processes, the electrothermia, that lasts until today. The current natural gas production scenario in Brazil is promising, considering the Pre-Salt production, which signals an opportunity to apply this natural resource to final energy uses with higher value, such as final energy for industry. In this context was structured this dissertation, comprising a data analysis technique development and its application to evaluate the insertion of natural gas in the Brazilian industrial sector and its impacts. The developed data analysis technique is constituted by the assessment of four indicators: Additional Demand (DA); Impact on Primary Energy (IEP); Impact on Carbon Emissions (IEC) and Impact on Energy Cost (ICE). In the results obtained, the Non-Ferrous Metals Sector was more prominent as it presented the greater additional demand for natural gas and the largest reductions in primary energy demand, CO2 emissions and energy costs. Other sectors that stood out were the Iron and Steel Sector and the Food and Beverages Sector. Considering 2013 as the base year, the additional demand for natural gas resulting from the substitution of fuel oil and electricity in heating processes would represent a 37% to 42% increase in the demand for natural gas in the Brazilian industrial sector, equivalent to 12% to 14% of Brazil\'s domestic natural gas supply, or 35% to 40% of Gasbol\'s maximum capacity. The impact on primary energy would represent a reduction of 1% to 2% of the primary energy demand of the Brazilian industrial sector. The impact on CO2 emissions would represent a reduction of 4% to 5% of the CO2 emissions associated to energy use of the Brazilian industrial sector. The impact on energy cost would represent a reduction of 2% to 4% of the energy costs associated with electricity and fuel oil of the Brazilian industrial sector. Thus, it is considered that there is an opportunity for the insertion of natural gas in the Brazilian industrial sector resulting from the substitution of fuel oil and electricity by natural gas in thermal processes. Overall, the substitution impacts reduce primary energy demand, CO2 emissions and energy costs. However, this is an energy-saving initiative through energy substitution, being necessary to further promote energy efficiency, for all end uses and types of final energy in use, to multiply the impacts in terms of reducing energy consumption and mitigating emissions, two important elements in the current debate on combating climate change.

O cimento está entre os materiais mais utilizados no mundo moderno e sua produção deverá crescer nos próximos 40 anos. Esta crescente produção será responsável pela emissão de um grande volume de CO2 na atmosfera, atualmente a indústria cimenteira é responsável mundialmente por 10% das emissões totais de CO2 e pode chegar a 30% em 2050. Portanto, a academia e a indústria estão desenvolvendo estratégias para reduzir este impacto ambiental, uma dessas estratégias é a substituição do clínquer por materiais cimentícios suplementares (MCSs). Para esta estratégia ser efetiva é necessário que estes materiais possuam: (i) viabilidade econômica; (ii) disponibilidade e; (iii) viabilidade técnica. Hoje os materiais suplementares mais utilizados são a escória de alto forno e a cinza volante, mas o aumento na produção do cimento não foi acompanhado pela oferta destes materiais. Assim, outros materiais suplementares estão sendo utilizados pela indústria, como é o caso das pozolanas naturais e artificiais. Portanto o objetivo deste trabalho é estimar a disponibilidade e distribuição geográfica de alguns materiais cimentícios suplementares no Brasil e avaliar a eficiência de seis cimentos pozolânicos comerciais e compará-los com um cimento com alto teor de clínquer quanto a reatividade, demanda de água e indicadores ambientais. Todos os materiais foram fisicamente e quimicamente caracterizados; pastas e argamassas foram analisadas em termos de reatividade, demanda de água e resistência mecânica; finalmente, foram estimados indicadores ambientais e de eficiência. Para pastas e argamassas sem dispersante o cimento com alto teor de clínquer e aqueles com adição de terra diatomácea demandaram mais água que os demais para um mesmo espalhamento, já com adição de superplastificante o cimento REF foi o que demandou mais água. O cimento com alto teor de clínquer foi o mais reativo em todas as idades e apresentou os melhores resultados do indicador de fração de água combinada e indicador de intensidade de ligante. Já para o indicador intensidade de carbono os melhores resultados foram obtidos para os cimentos com alto teor de substituição. No entanto, o estudo mostra que a redução do teor de clínquer não está diretamente relacionada à redução do impacto ambiental do cimento em seu uso, esta redução de impacto também está associada com a eficiência do ligante quanto a sua reatividade e demanda de água. / The cement is one of the most used materials in the modern world and its production should grow in the next 40 years. This growing production will be responsible for issuing a large volume of CO2 on the atmosphere, nowadays the cement industry is responsible worldwide for 10% of the total emissions of CO2 and it can reach 30% in 2050. Therefore, academia and industry are developing strategies to reduce this environmental impact, one of these strategies is the substitution of clinker by supplementary cementitious materials (SCMs). For this strategy to be effective it is necessary that these materials possess: (i) economic viability; (ii) availability and; (iii) technical feasibility. Today the most used supplementary materials are the blast furnace slag and fly ash, but the increase in the production of cement was not accompanied by the supply of these materials. Therefore, other supplementary materials are being used by the industry, as is the case of natural and artificial pozzolans. So, the aim of this work is to estimate the availability and geographic distribution of some supplementary cementitious materials in Brazil and evaluate the efficiency of six Portland pozzolan blended cements and compare them with a cement with high clinker content as to reactivity, water demand and environmental indicators. All materials were physically and chemically characterized; pastes and mortars were analyzed in terms of reactivity, water demand and mechanical strength; finally, environmental and efficiency indicators were estimated. For pastes and mortars without dispersant the cement with high content of clinker and those with the addition of diatomaceous earth ordered more water than the others to achieve the same spread, already with the addition of superplasticizer the cement REF was the one that ordered more water than the others. The cement with high clinker content was the most reactive in all ages and presented the best results of the binder efficiency indicator and binder intensity indicator. For the carbon intensity indicator, the best results were obtained for cements with high replacement content. However, the study shows that the reduction of the clinker content is not directly related to the reduction of the environmental impact of the cement in its use, this reduction is also associated with the binder efficiency in means of reactivity and water demand.

A produção de cimento gera um impacto ambiental negativo, principalmente relacionado à emissão de dióxido de carbono (CO2). O clínquer do cimento sulfoaluminato de cálcio belítico (CSAB) possui um menor teor de óxido de cálcio e é produzido com uma reduzida temperatura de sinterização (aproximadamente 200ºC a menos em relação ao clínquer Portland), sendo considerado mais eco-amigável. Para a produção do cimento CSAB são necessárias matérias-primas ricas em alumínio e convencionalmente a bauxita é o minério utilizado para compor a farinha, o que mais onera a produção desse tipo de cimento. Soma-se ainda o fato que a geração de resíduos e subprodutos industriais torna-se inerente aos processos e o coprocessamento de resíduos vem sendo cada vez mais utilizado por razões ambientais e energéticas. Logo, fontes alternativas de alumina são fundamentais para a viabilização deste cimento e o aproveitamento de resíduos agregaria um valor econômico e sustentável ao produto final. De modo estequiométrico, a bauxita pode ser completamente substituída pelo lodo de anodização do alumínio (LAA), o qual também pode complementar o conteúdo de alumínio de outros resíduos, valorizando-os. O objetivo deste estudo foi avaliar a produção e as propriedades de clínqueres/cimentos CSAB a partir da substituição da bauxita por cinza pesada e LAA. Para a caracterização das matérias-primas, clínqueres e cimentos nos estados anidro e hidratado foram utilizadas as seguintes técnicas: fluorescência de raios X; microscopia eletrônica de varredura e espectrometria por energia dispersiva; termogravimentria; calorimetria; e difração de raios X com refinamento pelo método de Rietveld. A partir dos resultados obtidos, a substituição da bauxita foi limitada a nível parcial devido à elevada formação de belita e periclásio. Nos clínqueres produzidos, foi constatado que a presença da cinza pesada favorece a formação da estrutura cristalina ortorrômbica da fase ye’elimita. A presença dos resíduos altera a quantificação das fases, porém não compromete a estabilização das mesmas. A presença dos resíduos na composição dos cimentos afeta o período inicial de hidratação devido à redução do conteúdo de ye’elimita. Nos clínqueres produzidos com cinza pesada, ocorre a formação de até 12,6% da fase alita a 1250ºC, principal constituinte do clínquer Portland. / Cement production generates high negative environmental impact, mainly associated to CO2 emissions. Calcium sulfoaluminate belite cement clinker (CSAB) has lower content of calcium oxide, and sintering reduced temperature (about 200°C lower than that used for Portland clinker), being considered as eco-friendly binder. For its production high amount of alumina is required, however the scarcity and high cost of bauxite make these cements costly. Additionally, the generation of waste and by-products becomes a drawback in the industrial processes and the coprocessing of wastes in cement plants is increasing for environmental and energy savings reasons. Alternative sources of alumina would add an economic and sustainable value to the final product and previous work has shown that the aluminum anodizing sludge can replace bauxite in the production process. Other sources of wastes can also be a possibility to increase the production and reduce the raw materials costs of these cements. Thus, the objective of this study was the evaluation of novel CSAB cements produced with bauxite replacement by bottom ash and aluminum anodizing sludge. CSAB cements were produced in the laboratory from different amounts of sludge and ashes. The raw materials, clinkers/cements and hydration products were physicaly-chemicaly and mechanical characterized. Results showed that the mineralogy composition of CSAB clinker was strongly affected due to the addition of bottom ash. The amount of bottom ash waste replacing bauxite controls the belite and periclase formation. Also it influences the early age hydration due the reduced ye’elimite formation and important changes in the crystalline structures of this phase occurs in the clinkers. Clinkers prepared from these replacement, are able to form 12.6% of alite (main phase Portland clinker), not normally found in CSAB clinkers, being sintered at 1250°C.

All around the globe the consumption of raw materials by the construction industries isaccumulating day by day resulting with an depletion of natural resources, increasing the environmental impacts and CO2 emissions all over the surroundings. Today steel and concrete are widely used and are dominating construction materials in construction industry. These two construction materials are different products and have distinct production flow with significantimpact on the environment. The amount of embodied energy and operational energy which is consumed in the process of production, recycling and reuse are becoming increasingly more important in the construction industries due to the potential shortage of natural resources in thenear by future and due to the inflation in the energy prices. This master’s thesis determines some of the problems of antagonistic environmental impacts due to the use of steel and concrete in the construction industries. To mitigatethese environmental impacts there are two technology and policy strategies summarizedin this thesis. i. Reduce consumption; andii. Material selection to reduce impacts.i. Reduce consumption: All around the globe the consumption of materials is growing day by day with an increase in the population resulting with a depletion of virgin materials. This depletion of virgin materials can be reduced with the help ofrecycling and reuse of the structural members. Recycling of structural members isalready practiced widely than reuse; reuse of the structural members additionallyreduces the consumption of virgin materials. High level of reuse of the structuralmaterials can be achieved by establishing design standards and regulations forstructural sections, and developing a market for reusable structural sections.ii. Material selection to reduce impacts: For the selection of constructionmaterials with minimum impact on the environment the designers needs tohave apropos education or tools. The main areas for augmentation areidentified as education of designers, and standardization and simplification ofselection tools like Life Cycle Assessment (LCA). Some of the main recommendations are: LCA tools standardization; reduce the impact sections and make these impact sections comprehendible and integrate uncertainty dataand educating designers about material selection tools with organized programs.

O cimento está entre os materiais mais utilizados no mundo moderno e sua produção deverá crescer nos próximos 40 anos. Esta crescente produção será responsável pela emissão de um grande volume de CO2 na atmosfera, atualmente a indústria cimenteira é responsável mundialmente por 10% das emissões totais de CO2 e pode chegar a 30% em 2050. Portanto, a academia e a indústria estão desenvolvendo estratégias para reduzir este impacto ambiental, uma dessas estratégias é a substituição do clínquer por materiais cimentícios suplementares (MCSs). Para esta estratégia ser efetiva é necessário que estes materiais possuam: (i) viabilidade econômica; (ii) disponibilidade e; (iii) viabilidade técnica. Hoje os materiais suplementares mais utilizados são a escória de alto forno e a cinza volante, mas o aumento na produção do cimento não foi acompanhado pela oferta destes materiais. Assim, outros materiais suplementares estão sendo utilizados pela indústria, como é o caso das pozolanas naturais e artificiais. Portanto o objetivo deste trabalho é estimar a disponibilidade e distribuição geográfica de alguns materiais cimentícios suplementares no Brasil e avaliar a eficiência de seis cimentos pozolânicos comerciais e compará-los com um cimento com alto teor de clínquer quanto a reatividade, demanda de água e indicadores ambientais. Todos os materiais foram fisicamente e quimicamente caracterizados; pastas e argamassas foram analisadas em termos de reatividade, demanda de água e resistência mecânica; finalmente, foram estimados indicadores ambientais e de eficiência. Para pastas e argamassas sem dispersante o cimento com alto teor de clínquer e aqueles com adição de terra diatomácea demandaram mais água que os demais para um mesmo espalhamento, já com adição de superplastificante o cimento REF foi o que demandou mais água. O cimento com alto teor de clínquer foi o mais reativo em todas as idades e apresentou os melhores resultados do indicador de fração de água combinada e indicador de intensidade de ligante. Já para o indicador intensidade de carbono os melhores resultados foram obtidos para os cimentos com alto teor de substituição. No entanto, o estudo mostra que a redução do teor de clínquer não está diretamente relacionada à redução do impacto ambiental do cimento em seu uso, esta redução de impacto também está associada com a eficiência do ligante quanto a sua reatividade e demanda de água. / The cement is one of the most used materials in the modern world and its production should grow in the next 40 years. This growing production will be responsible for issuing a large volume of CO2 on the atmosphere, nowadays the cement industry is responsible worldwide for 10% of the total emissions of CO2 and it can reach 30% in 2050. Therefore, academia and industry are developing strategies to reduce this environmental impact, one of these strategies is the substitution of clinker by supplementary cementitious materials (SCMs). For this strategy to be effective it is necessary that these materials possess: (i) economic viability; (ii) availability and; (iii) technical feasibility. Today the most used supplementary materials are the blast furnace slag and fly ash, but the increase in the production of cement was not accompanied by the supply of these materials. Therefore, other supplementary materials are being used by the industry, as is the case of natural and artificial pozzolans. So, the aim of this work is to estimate the availability and geographic distribution of some supplementary cementitious materials in Brazil and evaluate the efficiency of six Portland pozzolan blended cements and compare them with a cement with high clinker content as to reactivity, water demand and environmental indicators. All materials were physically and chemically characterized; pastes and mortars were analyzed in terms of reactivity, water demand and mechanical strength; finally, environmental and efficiency indicators were estimated. For pastes and mortars without dispersant the cement with high content of clinker and those with the addition of diatomaceous earth ordered more water than the others to achieve the same spread, already with the addition of superplasticizer the cement REF was the one that ordered more water than the others. The cement with high clinker content was the most reactive in all ages and presented the best results of the binder efficiency indicator and binder intensity indicator. For the carbon intensity indicator, the best results were obtained for cements with high replacement content. However, the study shows that the reduction of the clinker content is not directly related to the reduction of the environmental impact of the cement in its use, this reduction is also associated with the binder efficiency in means of reactivity and water demand.

The area of vegetable production is growing rapidly world-wide, as are efforts to increase production on existing lands in these labor- and input-intensive systems. Yet information on nutrient losses, greenhouse gas emissions, and input efficiency is lacking. Sustainable intensification of these systems requires knowing how to optimize nutrient and water inputs to improve yields while minimizing negative environmental consequences. This work characterizes soil nitrogen (N) dynamics, nitrate (NO3¯) leaching, greenhouse gas emissions, and crop yield in five diversified vegetable systems spanning a gradient of intensification that is characterized by inputs, tillage and rotational fallow periods. The study systems included a low input organic system (LI), a mechanized, medium scale organic system (CSA), an organic movable high tunnel system (MOV), a conventional system (CONV) and an organic stationary high tunnel system (HT). In a three-year vegetable crop rotation with three systems (LI, HT and CONV), key N loss pathways varied by system; marked N2O and CO2 losses were observed in the LI system and NO3– leaching was greatest in the CONV system. Yield-scaled global warming potential (GWP) was greater in the LI system compared to HT and CONV, driven by greater greenhouse gas flux and lower yields in the LI system. The field data from CONV system were used to calibrate the Root Zone Water Quality Model version 2 (RZWQM2) and HT and LI vegetable systems were used to validate the model. RZWQM2 simulated soil NO3¯-N content reasonably well in crops grown on bare ground and open field (e.g. beet, collard, bean). Despite use of simultaneous heat and water (SHAW) option in RZWQM2 to incorporate the use of plastic mulch, we were not able to successfully simulate NO3¯-N data. The model simulated cumulative N2O emissions from the CONV vegetable system reasonably well, while the model overestimated N2O emissions in HT and LI systems.

No description available.

No description available.

Governments and policy-makers are currently dealing with some key issues as energy security in countries dependent on oil imports; global economic development, including increased food production; and controlling global climate change and greenhouse gas emissions. The perception that biofuel could solve these challenges simultaneously has led to the implementation of policy and regulatory mechanisms on the mandatory use of biofuels, resulting in a sharp increase in biofuel production and consumption. Serious concerns about large-scale ethanol production have been raised regarding loss of biodiversity and competition for land between food and ethanol production. It is also suggested that sugarcane-based ethanol increases GHG emissions due to indirect land use change. Furthermore, sugarcane harvesting has been criticised for causing air pollution and bad working conditions for cutters. These criticisms have mostly been denied by Brazilian actors. This thesis seeks to clarify these divergent views and conflicts concerning Brazilian ethanol. It was carried out within a KTH research programme that uses frames in the analysis of conflicts emerging from the development and implementation of new technologies. Frame analysis can help improve understanding of such conflicts, which derive from differences in values, world views and beliefs and can be difficult to resolve. Frame analysis seeks to identify the particular factors determining the actions taken by different stakeholders, giving equal treatment to all actors. The results showed that the international views expressed in the media captured the attention of the public and policy-makers, and led them to frame ethanol as a destructive for nature fuel. The analysis identified that the ethanol as a threat to food security frame combined with the ethanol as a destructive for nature frame led the public and policy-makers to frame ethanol as a brown fuel. However, Brazilian actors frame ethanol differently: as a green and safe fuel. These differences have raised the conflicts that are analysed in this thesis. Furthermore, the analysis identified that the changes in the harvesting system, from manual to mechanised –besides decreasing air pollution- will cost the job of hundreds of thousands of cane cutters. Values and beliefs orientating such changes are analysed in the thesis. / QC 20110912

This thesis puts forth the means of a strategic approach to address a persistent problem in the energy system and in this way, to transition the built environment to a future state that is more exergy-aware to curb CO2 emissions. Such a vision is made possible by the six-fold contributions of the research work: I) An analytical model is developed, which for the first time, formulates the CO2 emissions that are compounded in the energy system as a function of the systematic failures to match the supply and demand of exergy. This model is namely the Rational Exergy Management Model or REMM. II) REMM is then applied to analyze the pathways in which it is possible to lead the built environment into addressing structural overshoots in its exergy supply to curb CO2 emissions. The cases that embody these pathways are also analyzed over a base case, including cases for sustainable heating and cooling. III) New tools are designed to augment decision-making and exemplify a paradigm shift in the more rational usage of exergy to curb CO2 emissions. These include a scenario-based analysis tool, new options for CO2 wedges, and a multi-fold solution space for CO2 mitigation strategies based on REMM. IV) The concept of a net-zero exergy building (NZEXB) is developed and related to REMM strategies as the building block of an exergy-aware energy system. The target of a NZEXB is further supported by key design principles, which address shortcomings in state-of-the-art net-zero design. V) A premier building that deployed the key design principles to integrate building technology in an innovative, exergy-aware design and received LEED Platinum is analyzed on the basis of the NZEXB target. The results validate that this building boosts net self-sufficiency and curbs compound CO2 emissions, which are then presented in a proposed scheme to benchmark and/or label future NZEXBs. VI) Based on the scalability of the best-practices of the NZEXB ready building, the means to realize a smarter energy system that has exergy-aware relations in each aspect of the value chain to curb CO2 emissions are discussed. This includes a target for such a network at the community level, namely a net-zero exergy community (NZEXC). As a whole, the results of the thesis indicate that the strategic approach as provided by REMM and the NZEXB target of the research work has the potential to steer the speed and direction of societal action to curb CO2 emissions. The thesis concludes with a roadmap that represents a cyclical series of actions that may be scaled-up at various levels of the built environment in a transition to be in better balance with the Planet. / QC 20111014