Thesis (M.S.)--Mississippi State University. Department of Agricultural Economics. / Title from title screen. Includes bibliographical references.

Thesis (M.S.)--University of Tennessee, Knoxville, 2002. / Title from title page screen (viewed Feb. 27, 2003). Thesis advisor: Atul Sheth. Document formatted into pages (ix, 70 p. : ill. (some col.)). Vita. Includes bibliographical references (p. 67-69).

Thesis (PH.D.)--Michigan State University. Chemical Engineering, 2008. / Title from PDF t.p. (viewed on Aug. 11, 2009) Includes bibliographical references (p. 179-189). Also issued in print.

Thesis (M.S.)--University of California, Davis, 2007. / Text document in PDF format. Title from PDF title page (viewed on August 28, 2009). "Received by ITS-Davis: September 2007"--Publication detail webpage. Includes bibliographical references (p. 114-116).

Thesis (Ph.D.) - University of KwaZulu-Natal, Pietermaritzburg, 2009. / Submitted to the African Centre for Crop Improvement. Full text also available online. Scroll down for electronic link.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 166-174).

A pesquisa por meio de projetos e planos, que induzem ações de sustentabilidade e inovação, tem alavancado o processo de desenvolvimento de vários países. Porém, neste movimento estão presentes conflitos, contradições e interesses que trazem resultados por vezes não desejados. As necessidades de preservação e conservação da natureza e os impactos ambientais no cotidiano das sociedades requerem mudanças de comportamento das empresas e do governo. Investimentos em pesquisa, ciência e tecnologia são fundamentais para estimular inovações e para estabelecer os limites dos usos e das formas de apropriação dos recursos naturais. Nesta dissertação, a partir de um projeto de natureza técnica, fez-se uma análise para verificar como os pesquisadores inserem a própria pesquisa nos contextos econômico, social, ambiental e político. O projeto analisado, intitulado "Florestas Energéticas na Matriz de Agroenergia Brasileira", coordenando pela Embrapa Florestas faz parte do Plano Nacional de Agroenergia, o qual é desdobramento das políticas públicas na busca de fontes alternativas de energia. O marco teórico de apoio para as discussões demandou a escolha de temas, tais como: ciência, tecnologia, sociedade, desenvolvimento, florestas, biomassa, inovação e sustentabilidade. A pesquisa foi de natureza qualitativa, com análise documental e bibliográfica, explorando recursos analíticos da lingüística e da interdisciplinaridade. Foram levantados termos que expressam aspectos estruturais do projeto: ambiental, econômico, social, e político. Após definidos os objetivos e os procedimentos metodológicos, foram trabalhados temas do desenvolvimento e tecnologia no contexto da economia brasileira. As discussões abrangeram os temas do projeto analisado, em especial os tópicos de florestas, biomassa, exploração, produção, consumo da madeira e resíduos. Assim, foi possível expor a compreensão de sustentabilidade e dos limites dos recursos naturais enquanto instrumentos de apoio para a elaboração de projetos de pesquisa. Os resultados da análise do projeto de pesquisa (Florestas Energéticas e os cinco projetos componentes) apontaram que o grande motivador das políticas públicas foi o aspecto econômico, e os demais aspectos; social, ambiental, e político, o complementaram. Assim, pode-se afirmar que os conteúdos temáticos dos textos apresentam um repertório variado e amplo da questão energética, nos propósitos de ações sustentáveis. As argumentações que se encontram no marco teórico fazem parte da esfera das atividades propostas pelo projeto, o que permite inferir vínculos e articulações entre os estudiosos e os pesquisadores do projeto. Na parte social, o projeto prevê a utilização de mão-de-obra e a geração de renda, e como conseqüência, melhoria da qualidade de vida. Nele, o termo "desenvolvimento sustentável" refere-se à questão socioeconômica e ambiental e pode representar as escolhas das gerações futuras no sentido de dar continuidade às ações pela vida. Na essência dos discursos que a ele se referem, destaca-se a atividade da silvicultura para a produção energética, a qual contribui com o equilíbrio dos processos naturais e industriais. Vale destacar o importante papel das políticas públicas na concretização de ações favoráveis às fontes alternativas e renováveis, e às pesquisas e investimentos, que repercutem na conservação e preservação do ambiente. / Research through projects which induce actions of sustainability and innovation, has promoted the development process of many countries. However, conflicts, contradictions and interests, which sometimes bring unwanted results, are present in this movement what may output some unwanted results. The need for preservation and conservation of nature and the environmental impacts on societies require changes on the behavior of corporations and government. Investments in research, science and technology are essential to stimulate innovation and to establish the limits of the uses and forms of appropriation of natural resources. In this dissertation, a technical research project was analyzed to check how the researchers inserted their own research in economic, social, environmental and political contexts. The analyzed project entitled "Florestas Energéticas na Matriz de Agroenergia Brasileira" is coordinated by Embrapa Florestas as part of the National Plan of Agro-energy (Plano Nacional de Agroenergia) which is an outcome of Brazilian public policies for alternative sources of energy. The theoretical basis for this research involved the selection of keywords such as: science, technology, society, development, forests, biomass, innovation and sustainability. This research was of qualitative nature with the analysis of documents and bibliography, exploring analytic resources from linguistics and interdisciplinarity. Words which express structural aspects of the project such as environment, economy, society and public politicies where identified. After the definition of objectives and methodological procedures, were addressed themes of development and technology in the context of the Brazilian economy. The discussions covered topics of the project, in special that ones related to forest biomass, exploration, production, consumption and waste wood. Thus, is was possible to expose an understanding of sustainability and the limits of natural resources as support instruments for the development of research projects. The results of the analysis of the research project (Florestas Energéticas and its five component projects) pointed out that the greatest motivator of public policies was the economic aspect while other aspects such as social, environmental and political were complementary to it. Thus, it can be assured that the thematic contents of the texts present a wide and varied repertoire on energies towards sustainable actions. The arguments found at the theoretical basis are included on the actives proposed on the project, which allows inferring on links and connections among researchers acting inside and outside of the project frame. On the social impact, the project foresees the use of manpower and income generation, and a consequence, improvement on quality of life. In it the term "sustainable development" refers to the socioeconomic and environmental issues. They may represent the choices of future generations in order to give continuity to the actions towards life. In essence of the discussions that refer to it, there is a highlight on forestry for energy production activities; which contributes to the balance of natural and industrial processes. It is worth noting the important role of public policy in the implementation of actions supportive of alternative and renewable sources, and also supportive of researches and investments that impact on environment conservation and preservation.

The work presented in this thesis was carried out with a particular view of enhancing the of coal fired fluidised bed hot gas generator (HGG) at the Cantley factory of British Sugar. It covers combustion of coal and biomass and their blends also called co-firing in a fluidised bed combustor. Particularly it focuses on the effect of introduction of moisture as part of fuel or injection of water into the bed on the reduction of excess air to get a stable bed temperature. Although this thesis is focused on increasing the throughput of the HGG, the study has a broad application and can be beneficial in utilising relatively cheap, poor quality, unprepared biomass materials. The results of this study can be helpful in devising systems to deal with wastes from different industries in co-combustion with a fuel of higher calorific value such as coal. Thus the study will have dual impact on the industry; addressing waste management issues on one hand and producing useful energy on the other. This may contribute towards meeting the targets of Kyoto Protocol by reducing emissions of carbon dioxide (COi) as biomass is thought to be COa neutral. The fluidised bed at Cantley is used to dry animal feed and has a design capacity of 40 MW but due to limitations of flow of fluidising gases caused by high flow resistance through sparge pipes, the combustor is running under capacity. Consequently, some of the animal feed has to be dried by using expensive oil fired drier. In any combustion system excess air is used to control combustion temperature. In fluidised bed combustion excess air is used to control bed temperature. If the bed is cooled by other means the requirement of excess air can be reduced. This is the basic idea behind this study which is aimed at enhancing the capacity of the HGG by cooling the bed and thus reducing excess air requirements. The excess air thus spared can be used to combust more coal in the bed and thus will reduce dependence on oil fired dryer and will have financial benefits for British Sugar. Different fuels including wood pellets, wood chips and sugar industry by-products such as vinasse, raffinate and pressed pulp were fired/cofired with Thoresby coal in a fluidised bed test rig installed at the University of Glamorgan. The blends of wood chips and pressed pulp with coal are co-fired at different moisture contents. The tests were conducted at different thermal inputs at a wide range of excess air levels. Most of the work is focusedon the combustion of blends of coal and pressed pulp in different proportions. It was found that the maximum proportion of the pressed pulp in the blend with coal which could be burned successfully in the fluidised bed is 50%. During combustion of different coal-pulp and coal-wood chips blends it was found that excess air requirement is reduced by around 20% in comparison to coal only firing, over the range of the operating conditions tested. Because of the presence of potassium in pressed pulp, which could cause agglomeration during combustion in fluidised beds, longer term tests were carried out with 50/50 blend of coal and pulp. No signs of agglomeration were observed when the rig was fired for 8 days for almost 7 hours a day. However, Scanning Electron Microscopy (SEM) analyses of bed samples taken at the end of every day have shown the accumulation of potassium in the bed up to 1%. For comparison purposes tests were also carried out by co-firing coal with raffiante and vinasse and then it was observed that the bed defluidised relatively quickly, within 40 minutes of co-firing. Post experiment SEM analysis confirmed the accumulation of potassium in the bed which was found to be around 8% for raffinate and around 10% for the vinasse experiment. It was found that the pulp is difficult to deal with and particularly its feeding into the fluidised bed could be a potential problem. Therefore, injection of water into the bed, a relatively cheaper and adaptable option, was also investigated. It was found that emissions of carbon monoxide due to incomplete combustion or water gas shift reaction would not be a problem as long as the bed temperature is controlled above 800 °C. It was found that the injection of water at a rate of 4.5 1/h into the bed fired at 17 kW reduced the air flow requirement by around 7.5 m3/h which corresponds to a reduction of almost 20% which agrees with the finding with coal-pulp blends co-firing. This excess air can be used to burn around 5 kW equivalent of more coal and thus result in an increase in the thermal capacity by around 30%. Therefore, it may be possible to enhance the thermal capacity of the HGG at Cantley by 30% by injecting water into the bed or by co-firing coal and pulp.

Microbial fuel cell (MFC) systems capable of both treating wastewaters and recovering energy have the potential for successful scale-up as a low carbon technology. These systems utilize microorganisms residing in biofilms as biocatalytic agents in the conversion of reduced substrates to electrical energy. As such, it is important to understand how MFC anodic biofilms develop over time and also how environmental parameters such as substrate type, temperature, carbon support material, anode architecture and optimized applied potentials also affect electrogenic performance. The type of substrate was found to have a large impact on the acclimation and performance of electrogenic biofilms. Acetate produced the highest power density of 7.2 W m 3 and butyrate the lowest at 0.29 W m"3, but it was also found that biofilm acclimation to these different trophic conditions also determined the MFC response to different substrate types i.e. both acetate and butyrate substrates produced power densities of 1.07 and 1.0 W m"3 respectively in a sucrose enriched reactor. The use of MFCs for wastewater treatment in temperate regions requires the development of reactor systems that are robust to seasonal fluctuations and are energy efficient. As such, system performance was examined at three different operating temperatures (10°C, 20°C and 35°C). At each temperature a maximum steady-state voltage of 0.49 V ± 0.02V was achieved after an operational period of 47 weeks, with the time to reach steady-state voltage being dependent on acclimation temperature. The highest COD removal rates of 2.98g COD L^d * were produced in the 35°C reactor but coulombic efficiencies (CE) were found to be significantly higher at pyschrophilic temperatures. Acclimation at different operating temperatures was found to a have a significant effect on the dynamic selection of psychrophilic, psychrotolerant and mesophilic anode respiring bacteria (ARB) and also influence the development of biofilm biomass, methanogenesis and electrogenic activity. Although start-up times were inversely influenced by temperature the amount of biomass accumulation increased with higher operational temperatures and this had a direct impact on biocatalytic performance. The three dimensional structure and porosity of different carbon anode materials affected anodic performance by determining the levels of surface area available for biofilm growth and the capacity for mass transfer to occur. Novel helical electrode configurations were used to look at the effect of altering turbulent flows to increase mass transfer rates and carbon surface areas available for electrogenic growth. The spiral with the highest amount of carbon veil and the smallest gap produced the highest power production of 11.63 W m"3 . Comparative studies of a logic controlled and un-controlled external load impedance showed that control affected the biocatalyst development and hence MFC performance. The controlled MFC better optimized the electrogenic anodic biofilm for power production, indicating that improved power and substrate conversion can be achieved by ensuring sustainable current demand, applied microbial selection pressures and near-optimal impedance for power transference.

Made available in DSpace on 2015-12-10T14:23:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-07-31. Added 1 bitstream(s) on 2015-12-10T14:29:49Z : No. of bitstreams: 1 000854202.pdf: 2437055 bytes, checksum: 513c4c156b8f513318e2cd7882656032 (MD5) / Em decorrência das atuais políticas ambientais aplicadas ao setor sucroalcooleiro, que propõem a proibição da prática da queima dos canaviais, toneladas de biomassa na forma do palhiço da cana-de-açúcar estão sendo deixadas no campo. Assim, em uma realidade de potencial crise energética no país e busca de alternativas sustentáveis na geração de energia, a bioenergia torna-se uma importante solução para este mercado e, portanto, o potencial energético do palhiço passa a ser investigado como um adicional nas centrais de cogeração de energia. Neste contexto, este trabalho propõe um estudo da viabilidade de soluções que visam o aproveitamento do palhiço da cana-de-açúcar em uma usina sucroalcooleira instalada e em operação no estado de São Paulo, gerando, assim, maiores excedentes de eletricidade tanto na safra quanto na entressafra. A fim de fornecer indícios da viabilidade de cada uma das soluções, foram empregadas investigações de caráter termodinâmico, termoeconômico e econômico. Cinco propostas de adequações da planta de cogeração foram analisadas, sendo que, em quatro delas, foram realizadas modificações e melhorias na planta já instalada, enquanto em um caso foi proposta a inserção de uma planta de cogeração paralela alimentada exclusivamente por palhiço. Dentre as soluções analisadas, além de se confirmar o elevado potencial do palhiço para incremento da produção de excedentes de eletricidade, foi possível obter em alguns casos um custo de eletricidade inferior aquele verificado atualmente na planta em operação. Entretanto, através da análise econômica constatou-se que a atual política de preços de venda de eletricidade aplicada ao mercado elétrico brasileiro, com valores frequentemente inferiores àqueles necessários para garantir o retorno de investimentos em ampliação da capacidade instalada, falta de incentivos fiscais e subsídios... / Due to the current environmental policies applied to the sugar and ethanol industry, which propose the prohibition of the canebrake burning act, tons of biomass in the form of sugarcane trash are being left on the field. Thus, in a reality of potential energy crisis in the country and pursuit of sustainable alternatives on the energy generation, the bioenergy suits as an important solution for this market and, therefore, the energy potential of the sugarcane trash comes to be investigated as an additional source at the power cogeneration plants. In this context, this work proposes a study for the viability of solutions which aim a more useful end to the sugarcane trash in an established and operating sugarcane mill in São Paulo state, generating, then, greater electricity surpluses in both harvest and interharvest seasons. In order to provide evidences for the viability of each solution, thermodynamic, thermoeconomic and economic inquiries were applied. Five adjustment proposals of the cogeneration plant were analyzed, wherein, four of them were modified and improved in the already established plant, whilst for the other one, the implantation of an adjunct cogeneration plant, fuelled solely by sugarcane trash, was suggested. Among the studied solutions, in addition to confirming the sugarcane trash's high potential as an increment for the extra electricity production, it was possible to obtain, in some cases, an inferior electricity cost compared to the one verified in the previous operational plant. However, by means of the economic analysis, it was ascertained that the current electricity price policy applied to the Brazilian electric market, with frequently lower prices compared to the ones needed to guarantee the return of the investments on the installed capacity expansion, lack of tax incentive and subsidy to the sector are still impediments for the viability of new projects