As a novel high temperature fuel cell, the direct carbon fuel cell (DCFC) is drawing ever-increasing attention due to its significant high conversion efficiency, diversified fuel resources and low pollution compared with conventional coal-fired power plants. Despite the advantages of the DCFC technology, there are a number of fundamental and technological challenges which need to be overcome for its further development and commercialization. One of the major hurdles in current study of the DCFC is that the efficacy of carbon fuels is still unclear. Meanwhile, the effects of impurities in the carbon fuels on the performance and lifetime of the DCFC are still up for debate. Furthermore, the molecular-level study on the mechanism of electrochemical oxidation of carbon fuels in the DCFC is limited by the lack of techniques to detect the reaction intermediates at high temperature. Finally, how to scale up the DCFC system with suitable hardware materials and optimum structural designs needs further investigation. Based on successfully developing a DCFC system with a stirring molten carbonate electrolyte, various commercial and self-made carbon fuels including activated carbons, carbon blacks, graphitic carbons, coals and carbon nanofibers (CNFs) are systematically characterized and evaluated in this thesis. It is found that the nature of carbon fuels plays an important role in the anodic performance of the DCFC. A higher surface area and a smaller particle size of carbon fuel can effectively improve its electrochemical reactivity by increasing the interaction between the carbon particles and the molten carbonate electrolyte. On the contrary, a higher graphitic degree of carbon fuel results in a lower electrochemical reactivity in the DCFC due to the less reactive sites such as edges and defects on carbon surface. Furthermore, the order of the electrochemical reactivities for carbon fuels is in good agreement with the concentration of oxygen-containing functional groups on their surface, which is believed to play a key role in the electrochemical oxidation of carbons in the DCFC. In order to better understand the relationship between the surface chemistry of carbons and their electrochemical performance in the DCFC, various pre-treatment techniques including acid washing, air-plasma treatment, air oxidation, pyrolysis and the pre-electrochemical oxidation (in molten alkali carbonate electrolytes) have been conducted on the carbon fuels. It is shown that both the HNO3 washing and pre-electrochemical oxidation are much more effective to improve the electrochemical reactivities of carbon fuels compared to other pre-treatment techniques, which is attributed to the significant changes in the microstructure of carbon fuels and more surface oxygen functional groups produced during the pre-treatments. In contrast, the pyrolysis treatment results in a sharp decrease of electrochemical reactivity of carbon fuels due to the decreases in oxygen-containing surface groups and surface areas, and the increase of their graphitic degrees. For the sake of the optimum operational conditions for the DCFC system, the influences of stirring rates, the carbon fuel loadings and fuel cell temperatures on the anodic performance of the DCFC are investigated. It has been shown that the carbon discharge rates can be significantly boosted by effective stirring and high carbon fuel concentrations due to an improved mass transport. A higher operation temperature can also increase the current density and open circuit voltage of the DCFC. However, the complete electrochemical oxidation of carbon into CO2 can be only achieved at the low operation temperature of 600-700 ºC, while the partially electrochemical oxidation of carbon into CO occurs at 800 ºC, which will significantly decrease the carbon efficiency to less than 10% at 800 ºC. In the study of self-made CNFs as fuels for the DCFC, both microstructure and electrochemical reactivity of CNFs are highly dependent on their synthesis conditions. Compared with Ni-Al2O3 catalyst, the coprecipitated Ni-Cu-Al2O3 catalyst produced more CNFs with higher electrochemically reactivity. Over the same catalyst, the CNFs synthesized at lower temperature typically have higher surface areas, more surface oxygen functional groups and lower graphitic degrees, thereby leading to a higher electrochemical reactivity in the DCFC tests. In an effort to study the catalytic effects of mineral impurities on the electrochemical performance of the DCFC, Al2O3 and SiO2 present passivation effects in the anodic reaction. In contrast, the CaO, MgO and Fe2O3 show catalytic effects in the carbon electrochemical oxidation, which is demonstrated by the increases of current densities at low over-potentials in the polarization curves.

Thesis (Ph. D.)--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 173-188).

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-03-21T16:54:52Z No. of bitstreams: 1 DÉBORA JAMILA NÓBREGA DE MELO - DISSERTAÇÃO PPGEQ 2015..pdf: 1660411 bytes, checksum: 435dc571b5f61082152afe1a09c340cb (MD5) / Made available in DSpace on 2018-03-21T16:54:52Z (GMT). No. of bitstreams: 1 DÉBORA JAMILA NÓBREGA DE MELO - DISSERTAÇÃO PPGEQ 2015..pdf: 1660411 bytes, checksum: 435dc571b5f61082152afe1a09c340cb (MD5) Previous issue date: 2015-09 / CNPq / Diante da futura escassez dos recursos energéticos originados do petróleo e seus derivados, aliados aos impactos ambientais causados pelo consumo desenfreado de recursos naturais, faz-se necessário a busca por produção de energias alternativas e limpas. Nesse ínterim, surgem as microalgas como potenciais de produção de biocombustíveis, por sua elevada taxa de crescimento e capacidade produtiva de lipídios e carboidratos. Porém, o alto custo de manutenção ainda inviabiliza sua produção. Dessa forma, esse trabalho busca aumentar a produção de microalgas utilizando a vinhaça, um resíduo da indústria sucroalcooleira altamente nutritivo e poluidor, e reutilizando resíduos do próprio cultivo como suplementação nutricional ao meio de cultura. A microalga Chlorella sp. foi cultivada em meio Bold’s Basal Medium (BBM) modificado, suplementado com de 5, 10 e 15% de vinhaça e resíduos de cultivos com diferentes concentrações, reutilizados por até três vezes. O sistema de cultivo adotado foi o mixotrófico. Foram calculadas as velocidades específicas de crescimento máximas e os tempos de geração dos cultivos suplementados com vinhaça e resíduos de cultivos. Calcularam-se as remoções de Demanda Química de oxigênios dos cultivos suplementados com vinhaça. Foram quantificados os teores de açúcares redutores e lipídios das biomassas cultivadas com 10% de vinhaça e sem suplementação. Foi verificado que os cultivos suplementados com 5 e 10% de vinhaça apresentaram maior densidade celular que o cultivo sem suplementação. As taxas de crescimento máximas e os tempos de geração dos cultivos com 5 e 10% de vinhaça foram muito próximas, diferente do cultivo suplementado com 15% de vinhaça que apresentou inibição no crescimento. As remoções de DQO foram elevadas e em média 85%. A utilização dos resíduos de cultivos favoreceu o crescimento das microalgas, apresentando melhores resultados os cultivos suplementados com resíduos de segunda reutilização, em especial os cultivos suplementados com resíduos originados de um cultivo com adição de vinhaça. A biomassa da Chlorella sp. cultivada com suplementação de 10% de vinhaça apresentou 11,50% de lipídios, 0,33% de açúcares redutores. Estudos mais aprofundados devem ser realizados para uma melhor caracterização da biomassa para verificar a influência da suplementação do meio com vinhaça na produção de proteínas e carboidratos totais. / In the face of future scarcity of energy resources derived from oil and its derivatives, coupled with the environmental impacts caused by rampant consumption of natural resources, it is necessary to search for a renewable and clean energy. In the meantime, there are microalgae with potential of biofuel production due to its high growth rate and productivity capacity of lipids and carbohydrates. However, the high cost of maintenance still prevents its manufacture. In this way, the present work aims to increase the production of microalgae using vinasse which is a residue of highly nutritious sugarcane industry and a polluter, and reusing waste from the own cultivation as a nutritional supplement to the culture medium. The microalgae Chlorella sp. was grown in a modified Bold's Basal Medium (BBM), supplemented with 5, 10 and 15% of vinasse and residues of cultivations with different concentrations in what they were reused at maximum of three times. The adopted cultivation system was the mixotrophic. Calculations were made to obtain the specific maximum speed of growth and the generation times of cultivations supplemented with vinasse and cultivation waste. Also, it was calculated the removals of Chemical Oxygen Demand (COD) of cultivations supplemented with vinasse. For the next step, it was quantified the reducing sugars and lipids of biomass cultivated with 10% of vinasse and without supplementation. It was verified that the cultivation supplemented with 5 and 10% of vinasse showed higher cell density than the unsupplemented cultivation. The maximum growth rates and generation times of cultivations with 5 and 10% of vinasse were very close whereas cultivation supplemented with 15% of vinasse showed growth inhibition. The removals of COD were high and averaged at 85%. The use of cultivation residue has favored the microalgae growth, presenting best results for the cultures supplemented with second reuse waste, in particular cultures supplemented with residues derived from a culture with addition of vinasse. The biomass of cultivated Chlorella sp. with supplementation of 10% of vinasse showed 11.50% lipids, 0.33% of reducing sugars. Further studies should be performed to better characterize the biomass to check the influence of the medium supplementation with vinasse in the production of proteins and total carbohydrates.

Abstract Background: Sustainability practices have become a crucial factor for firms since there are external and internal pressures that expect firms to act environmentally friendly. Especially within organizations that are owned by family, being sustainable enables them to pass their firm in a good condition to the next generation. One way firms can be sustainable is through adopting clean technology strategy as it can provide both environmental and economic benefits to firms. Being sustainable and having the ability to implement clean technology requires a long-term vision or long-term orientation (LTO); a characteristic often associated with family-controlled businesses (FCBs). Purpose: The purpose is to examine the adoption of clean technology within family-controlled firms (FCBs) and non-family-controlled firms (Non-FCBs). The aim is to explore if there are certain characteristics of FCBs that facilitate implementation of clean technologies. Method: This research is based on qualitative research method with an abductive approach and interpretivism philosophy. The primary data is collected through semi-structured interviews with four companies of which three are family-controlled businesses and one is a non-family- controlled business. Conclusion: FCBs are more inclined to invest in clean technologies. The extent to which a company does or does not implement clean technologies depends not only on the institutional values of an organization but also how deeply one or more of the three LTO dimensions are implanted in those values.

Carbon offsetting has been an institutionalised response to climate change for over a decade. Over this period, climate change has become more severe and calls for climate justice have become increasingly insistent. Yet the normative controversies of carbon offsetting remain unresolved, as debates about the environmental quality, development impacts and ethical implications of carbon offsetting continue. This thesis explores the relationship between morality and carbon offsetting in three domains. First it provides an evaluation of the ethics of offsetting. Second it gives an account of the 'lay normativity' of the market, describing how carbon market actors interpret and act upon issues of moral concern. And third, it explains offsetting's moral economy. First, the thesis examines the moral rationales for and problems of offsetting in order to clarify the bases of criticisms levelled at offsets by researchers concerned about trends in neoliberal environmental governance. In evaluation of the ethics of offsetting, the PhD recognises some limited rationales, but mainly highlights widespread problems including lack of environmental integrity and failure to produce 'sustainable development'. The structure of the market is shown to create opportunities for malpractice and difficulties for reform. Second, building on work in cultural political economy, the research describes carbon offsetting's lay normativity. The account is based on interviews with over sixty carbon offset market actors including project developers, consultants, auditors, regulators, retailers and buyers in the UK, continental Europe, and in India. Findings show that the market is founded on ethical principles: offsetting is nothing without notions of environmental and developmental care. Critiques of, and reforms to, offsetting are also grounded in principled debate. But carbon market actors often use their power to further commercial interests that are not aligned with production of environmental or developmental value. And yet, even as rationales are ignored and problems are amplified, market actors maintain a discursive semblance of moral behaviour through forms of justification, story-telling and identity work. Third, the thesis explains how principles, profit and power combine to affect the governance of offsetting. It shows that the concentration of power among profit-seeking actors drives the production of offsetting's moral problems in the stages of project development, regulation and retail. Commercial interests in the politics of knowledge lead to manipulation of the discursive framings through which people come to understand offsets. Ethical narratives are deployed to sustain the market in states of dysfunction, enabling privileged groups to gain exchange value at the expense of climate protection and sustainable development. Through this explanatory work, the PhD contributes an original application of ideas about moral political economy to the case of climate change and carbon trading, demonstrating that powerful actors can shape culture and alter our perceptions of right and wrong.

O Protocolo de Quioto estabeleceu, entre outras ferramentas, o mecanismo de desenvolvimento limpo (MDL) que permite a atuação dos países em desenvolvimento, tais como China, Índia e Brasil, uma participação relevante no chamado mercado de carbono. Essa participação consiste no desenvolvimento de projetos para redução da emissão de Gases de Efeito Estufa (GEE) que objetivam contribuir com o cumprimento da meta de redução das emissões estabelecida para os países industrializados, bem como promover o desenvolvimento sustentável nos países anfitriões, que sediam os projetos. O objetivo deste trabalho foi analisar atividade de projetos de MDL, buscando identificar suas contribuições para o desenvolvimento sustentável. Para atingir este objetivo, foram identificados os principais modelos de avaliação das contribuições de atividades de MDL para o desenvolvimento sustentável, após escolhido um modelo para a avaliação dos projetos de MDL brasileiros, foi realizado um estudo de caso múltiplo com quatro projetos de MDL de diferentes tipos de atividade. Conclui-se, com base nos casos analisados, que os projetos apresentam contribuições para o Desenvolvimento Sustentável do país, mas, na maioria dos casos, o MDL não foi o principal motivador, portanto, é muito provável que as atividades fossem realizadas mesmo sem o apoio financeiro obtido através do MDL. / The Kyoto Protocol established, among other devices, the clean development mechanism (CDM), which provides developing countries such as China, India and Brazil with a material interest in the so-called carbon market. This involves the development of projects aimed at reducing the emissions of greenhouse gases (GHG) that contribute towards achieving the emissions reduction target established for the industrialized countries as well as promoting sustainable development in the host countries hosting the projects. The objective of this study was to analyze the activity of CDM projects in order to identify the contributions they provide towards sustainable development. To achieve this goal, the main models for assessing the contributions of CDM activities towards sustainable development were identified. After choosing a model to be used in assessing CDM projects in Brazil, a multiple case study was carried out with four CDM projects engaged in different types of activity. Based on the analyzed cases, it was concluded the projects provide contributions towards the sustainable development of the country, though in most cases, the CDM was not the main motivator. Therefore, it is very likely that the activities would have been developed out even without the financial support obtained through the CDM.

A limpeza dos aços está diretamente associada ao conteúdo de óxidos dos mesmos, sendo que os diferentes tipos de inclusões não-metálicas presentes podem prejudicar desde os processos de fabricação e conformação até as características necessárias para a aplicação do produto final. As inclusões se formam e se modificam ao longo dos processos de fabricação, e estão relacionadas principalmente às práticas de refino secundário e de lingotamento. Essas inclusões estão sempre presentes nos aços, de modo que é impossível se produzir um aço completamente livre das mesmas. Atualmente, existe uma série de pesquisas buscando o desenvolvimento de práticas e de processos para incrementar a limpeza dos aços. Entre essas está o desenvolvimento de novos materiais refratários adequados às diversas etapas de uma Aciaria. Com especial importância na limpeza dos aços estão as práticas e tecnologias aplicadas no lingotamento contínuo. Neste trabalho foi avaliada a influência do uso de nitrogênio injetado através de poros no colo das válvulas submersas sobre a lingotabilidade e limpeza dos produtos laminados a partir de tarugos. Para este estudo foram testadas diferentes vazões de gás e depois mensurado seu efeito. As técnicas utilizadas para a avaliação foram: verificação da abertura dos tampões; índice de sucateamento nas linhas de inspeção; severidade em ultrassom pelo método de imersão; análise dos teores de oxigênio total e nitrogênio e análise pelo método de distribuição de valores extremos da maior inclusão estimada. Os resultados práticos foram então comparados entre os lotes escolhidos para o teste. Verificou-se através dos dados coletados boa compatibilidade entre as diferentes variáveis e coerência dos resultados com os relatos da literatura. O uso de gás nitrogênio se mostrou ser potencialmente benéfico para a melhoria da limpeza e lingotabilidade do aço, apesar de mais testes serem necessários para a validação das hipóteses levantadas. / The steel cleanliness is directly associated to its inclusion content. The different kind of non-metallic inclusion can harm from the manufacturing and forming processes up to the demanding characteristics for the final products. The inclusions are formed and modified along the steel manufacturing process, and they are related mainly to the secondary refining and casting of steel. These inclusions are always present in the steel, so it is hardly possible to produce steels completely free of them. Nowadays, there are several fields of research concerning with the development of practices and processes to improve steel cleanliness. The development of new lining materials which are suitable for each melting shop step is one of these fields. With special importance over the steel cleanliness issue, the practices and technologies applied to the continuous casting process can be cited. In this work, the influence of nitrogen injection though the pores of the submerged entry nozzle over the castability and cleanliness of rolled products was evaluated. For this study, different gas flows were tested and then measured its effects. The techniques used for the evaluation were: stopper rod opening; rejection index during the inspection lines; severity in immersion ultra-sonic inspection; total oxygen and nitrogen content analysis and largest inclusion diameter estimated by extreme values distribution. The practical results for each lot of steel were then compared. It was verified from, the collected data, good compatibility between these different variables and coherency of the results with the experiences reported in the literature. The use of nitrogen gas showed itself to be potentially good for the improvement of cleanliness and castability of steel, though more trials are necessary for the validation of the considered hypothesis.

Addressing the low power generation of anodic biocatalysts is pertinent to the advancement of microbial fuel cell technology. While Propionibacterium freudenreichii ssp. shermanii has shown potential as a biocatalyst, its incomplete consumption of the anodic substrate is a persistent issue. This research aims to optimize substrate consumption to increase power generation using Propionibacterium freudenreichii ssp. shermanii as a biocatalyst. The effect of coculturing Geobacter sulfurreducens with Propionibacterium freudenreichii ssp. shermanii was investigated. The cocatalyst and pure culture performance was tested in an air-cathode microbial fuel cell. Geobacter sulfurreducens produced the highest maximum power density among the experimental cases. Power density produced by Propionibacterium freudenreichii ssp. shermanii was improved in the air-cathode design compared to previous experiments performed in an H-type design. The novel cocatalyst was shown to produce electricity, however a full characterization to elucidate the contribution to power generation by each microbe would be desirable to investigate.

As indústrias farmacêuticas que utilizam salas limpas, em seus processos produtivos, devem controlar ao máximo o nível de contaminantes microbiológicos, baseada na legislação RDC 210 que determina o cumprimento das diretrizes estabelecidas no Regulamento Técnico das Boas Práticas para a Fabricação de Medicamentos. Diante deste cenário, a proposta deste trabalho é avaliar o processo de fumigação com o reagente formaldeído, para a limpeza e desinfecção de salas limpas do Instituto de Tecnologia de Imunobiológicos Bio-Manguinhos. Então, foram desenvolvidas as seguintes etapas: diagnóstico com as indústrias farmacêuticas para traçar um perfil quanto ao uso da fumigação; quantificação de resíduos gerados; avaliação da exposição dos operadores ao formaldeído que é cancerígeno e acompanhamento dos resultados do monitoramento ambiental do ar e de superfícies, inicialmente na sala limpa do SEFBC, cuja atividade principal é a formulação de vacinas bacterianas e biofármacos, após a implantação do espaçamento da fumigação. Os resultados discutidos na presente dissertação mostraram, que a maior parte das indústrias farmacêuticas, não realiza a desinfecção por intermédio da fumigação e que o resíduo gerado neste processo é o mais crítico. E, sobretudo, o monitoramento microbiológico do ar e de superfícies da sala limpa do SEFBC, a partir da metodologia adotada de espaçamento da fumigação, comprovou que não é necessário o emprego deste processo de forma rotineira, para garantir os níveis exigidos de limpeza e desinfecção da respectiva área / Pharmaceutical industries that use clean rooms for their productive processes, must control to a maximum the level of microbiological contaminants, based on RDC 210 legislation that determines the fulfillment of lines in the directions established by the Technical Regulation Program for a Good Medicine Manufacturing. Ahead to this scene, the purpose of this work was to evaluate the process of fumigation with reacting formaldehyde, for the cleanness and disinfection of clean rooms of the Bio-Manguinhos Institute of Technology of Imunobiológicos. Then, the following stages had been developed: diagnosis with the pharmaceutical industries in order to get a scenario on the use of fumigation; quantification of the residues generated; evaluation of the exposition of operators to formaldehyde, a cancerigenous agent, and screening of the results of the environment monitoring of the air and surfaces, initially in the clean room of the SEFBC, in the areas of biopharmaceuticals formulation, and after a proper implementation of a fumigation process, at pre-defined intervals. The results thus obtained showed that most of the pharmaceutical industries no longer use disinfection for fumigation and that the residues generated in this process is the most critical problem. The overall microbiological monitoring of the air and surfaces of SEFBC clean room, according to the proposed methodology for fumigation, proved that the use of this process as a routine is not essential to guarantee the demanded levels of cleanness and disinfection of the respective areas

Indigenous peoples are increasingly using renewable energy technologies to meet a variety of objectives. In so-called Canada, there has been a dramatic rise in Indigenous renewable energy projects due to economic, environmental, and legal trends. Nowhere are these trends more evident than in the province of British Columbia (BC). In the early 2000s, the colonial government privatized the electricity system, sparking a rapid expansion of run of river hydro projects on Indigenous lands. Over time, and with much effort, First Nations in BC began to participate in and ultimately benefit from the shift to independent power production. However, just as they increased their involvement in the renewable energy sector, the government withdrew its commitment to purchase private power for the foreseeable future. One way to understand the implications of this policy reversal is to examine it through the lens of energy justice. Using a justice framework, this research explores how First Nations are involved in renewable energy developments in BC as well as the significance of this involvement for Indigenous self-determination. Drawing from two case studies and survey data from First Nations across the province, this thesis argues that the decline in power procurement programs is not simply a barrier but an injustice. I first illustrate how provincial energy policies have shaped and been shaped by Indigenous renewable energy ambitions. While First Nations were not the intended beneficiaries of these policies, they nonetheless seized the opportunity to sell electricity to the grid. I also compare the approaches of two Indigenous power producers, Kanaka Bar Indian Band and Sts’ailes First Nation, arguing that they have generated important economic benefits by strategically navigating the private power industry. Lastly, I document how members of Kanaka Bar have leveraged the Kwoiek Creek hydro project to address the adverse impacts of colonization and further their aims of self-determination. Based on these findings, I conclude that Indigenous renewable energy projects are themselves forms of energy justice and as such, must be supported through a variety of means. / Graduate