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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Life Cycle Assessment of a Pilot Scale Farm-Based Biodiesel Plant

Wasserman, Eli Shawn Jordan 07 May 2013 (has links)
This study used environmental life cycle assessment (LCA) to investigate waste vegetable oil (WVO) biodiesel production at the University of Guelph, Ridgetown Campus, Centre for Agricultural Renewable Energy and Sustainability (CARES). CARES production data and Natural Resources Canada’s GHGenius LCA data were utilized to conduct a well-to-gate LCA. A range of scenarios were studied including using soybean oil feedstock and implementing methanol recovery. Results suggest that methanol is the environmental bottleneck of the WVO biodiesel production system. Results also suggest soybean biodiesel production released more GHG emissions and consumed more energy than both WVO biodiesel or petroleum diesel production. LCA is an iterative process. Due to the study’s limited scope, and status as a screening study, it is recommended that the study of the impacts of the CARES facility be redone with more reliable facility data, that it include the anaerobic digester, as well as a well-to-wheels boundary. / University of Guelph
2

Sustentabilidade de cadeias de reciclagem do óleo de fritura / Sustainability of the waste frying oil recycling chains

Renato Correa Netto 10 March 2010 (has links)
Falsamente percebido como não agressivo ao meio ambiente pela sua origem verde, o óleo de fritura usado não tem uma cadeia de reciclagem formal. A população, as empresas e os diferentes níveis de governo têm atuação variada e não coordenada para fazer com que este resíduo tenha um destino ambientalmente correto. Este trabalho mostra como funcionam as cadeias que reciclam o óleo de fritura, estabelecendo elementos de avaliação de sua capacidade de se firmarem no tempo, de se consolidarem para assegurar sua sustentabilidade. A partir de uma revisão conceitual de indicadores de sustentabilidade é definida um método de avaliação e feita sua aplicação às cadeias que tratam o resíduo oriundo de Taubaté e S. José dos Campos. Seguiu-se esta cadeia da fonte aos usuários finais situados mesmo fora destas cidades. Na forma de pesquisa qualitativa exploratória, são entrevistados todos os tipos de agentes que atuam nestas cadeias, mostrando sua perspectiva da situação atual e da futura. O estudo mostra que as cadeias de reciclagem do óleo de fritura são poucas, fracas, vivem na informalidade e por vezes dependem de ações de voluntariado. Elas carecem de uma presença de governo e não poderão ser sustentáveis sem que respeitem as relações da sociedade e se organizem para serem eficientes de modo a gerar maior valor econômico. É fornecida uma visão abrangente e atualizada da questão, identificando os poucos elementos de sustentabilidade existentes bem como as oportunidades para que cada agente revise sua forma de contribuição para o fortalecimento destas cadeias e consequente redução do impacto ambiental deste resíduo. / Wrongly perceived as having no impact on the environment due to its origin, the waste frying oil doesnt seem to have a structured recycling chain. People, industry, and different governmental levels operate on different ways that are not coordinated, therefore, providing a disposal path that could ship this waste to an environmentally correct destination. This study shows the way the recycling chains of cooking vegetable oil are functioning, thus identifying the components for assessing their capacity to stand the test of time and consolidate their sustainability. Departing from a review on sustainability indicators, this study proposes an assessment methodology that was applied to the existing residue recycling chains in the municipalities of Taubaté and São José dos Campos. The chain was described from its sources to the end users even if they were located far from the referred cities. Structured as a qualitative exploratory survey, all types of agents that operate these chains were interviewed and provided their perspectives on the current status and future prospective of this activity. The study shows that the existing waste frying oil recycling chains are few, weak, informal, and rely, frequently, on volunteerism. There is a need for a greater government presence on stimulating and regulating these chains or they will not become sustainable nor respect society rules and relationships, therefore, function as a more organized entity to improve its efficiency and add more value to the chain. An industry perspective was also provided, identifying few existing sustainable characteristics and opportunities for agents to contribute in making these chains stronger, what, in the end, will reduce the environmental impact of this residue.
3

Cogaseificação de serragem de pinus e lodo de esgoto em leito fluidizado / Cogasification of pinus sawdust and sewage sludge in fluidized bed

Vissotto, João Paulo, 1982- 23 August 2018 (has links)
Orientador: Caio Glauco Sánchez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-23T18:32:48Z (GMT). No. of bitstreams: 1 Vissotto_JoaoPaulo_M.pdf: 17443827 bytes, checksum: 1532a467facbbea36dcaa47864ef9b7d (MD5) Previous issue date: 2013 / Resumo: Este trabalho aborda o estudo da cogaseificação de dois tipos de resíduos de biomassas (serragem de pinus e lodo de esgoto sanitário esgoto sanitário e industrial da cidade de Americana - SP) com o objetivo de comprovar experimentalmente os efeitos sinérgicos de misturas dessas biomassas. O lodo de esgoto não tem PCI suficiente para sustentar o processo de gaseificação sozinho, assim sua mistura com a serragem possibilita a realização do processo, além da diluição de possíveis contaminantes. Na caracterização das biomassas escolhidas, foram determinados os valores de PCI para o pinus de 17,19 MJ.kg-1 e para o lodo de 11,48 MJ.kg-1. Os teores de voláteis foram de 89,69 % e 58,32 % respectivamente. Os ensaios foram realizados no gaseificador do Laboratório de Combustão e Gaseificação do Departamento de Engenharia Térmica e de Fluídos da Faculdade de Engenharia Mecânica da UNICAMP, que é um reator de leito fluidizado borbulhante. Durante os ensaios de gaseificação foram selecionados dois fatores de ar para gaseificação exclusiva de pinus (0,30 e 0,50). Os valores de poder calorífico do gás produto foram calculados a partir da concentração do gás obtido, determinado por cromatografia gasosa, sendo os valores de 3,63 ± 0,4 MJ. Nm-3 e 1,92 ± 0,2 MJ. Nm-3 respectivamente. A adição de lodo para os ensaios de cogaseificação foram à razão de 25 % em massa, base seca, para o fator de ar de 0,30, pois nesse fator de ar ocorreu o melhor PCI do gás e o melhor rendimento a frio do gaseificador com gaseificação de pinus puro (37,1%). O valor de PCI para o gás produto da cogaseificação foi de 2,62 ± 0,67 MJ. Nm-3. O rendimento médio do gaseificador caiu para 29,3% / Abstract: This work aims to study the cogasification of two types of biomass residues (sawdust pine and sanitary and industrial sewage sludge from Americana City - São Paulo State) in order to experimentally demonstrate the synergistic effects of mixtures of these biomasses .The LHV of the sewage sludge is not enough to sustain the gasification process alone, so its mixture with sawdust allows the realization of the process and the dilution of possible contaminants. In the characterization of biomasses, the LHV values were for pine 17.19 MJ.kg-1 and for the sludge 11.48 MJ.kg-1. The content of volatiles were 89.69 % and 58.32 % respectively. Experiments were performed in the gasifier of The Combustion and Gasification Laboratory, Department of Thermal Engineering and Fluid Mechanics of the Faculty of Mechanical Engineering , UNICAMP , which is a bubbling fluidized bed reactor. During the gasification tests, two air ratio were selected for gasification of pine alone (0.30 and 0.50). The low heating value of the product gas was calculated from the gas concentration, determined by gas chromatography, with values of 3.63 ± 0.4 MJ.Nm-3 and 1.92 ± 0.2 MJ.Nm-3 respectively. The addition of sewage sludge for cogasification was in the rate of 25 % on dry basis, for 0.30 air ratio, because in this air ratio occurred the best LHV in the gas and the best performance of gasifier with pure pine ( 37.1 %). The average value of LHV for gas product of cogaseificação was 2.62 ± 0.67 MJ . Nm-3. The average efficiency of the gasifier fell to 29.3 % / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica
4

An industry analysis of the South African biofuels industry

Cilliers, Bronwyn Lee January 2012 (has links)
Biofuels have been used as an energy source for heating and cooking since the beginning of time. However, recent changes in the demand for energy, and in particular, renewable energy, have spurred the growth of liquid biofuel industries in developed countries. Many developing countries, including South Africa have the potential to produce biofuels with benefits extending into the economic and social spheres. Despite government commitments and targets, the South African biodiesel and bio-ethanol industries have stalled in the starting blocks. This research aims to assess the reasons why. South Africa does not have the climate to compete with Brazil in bio-ethanol production and the scope for bioethanol is limited by environmental factors. However our neighbours show significantly more promise in this area. Biodiesel production is more likely to be commercially viable due to the country’s ability to grow oil crops and the need for the by-products. Despite the availability of land for cultivation of energy crops, the required technology and suitable infrastructure, progress has been slow. Uncertainty, high risk and misdirected government interventions have hampered investment in the sector and those involved in biofuel projects are very negative about the government’s ability to stimulate the industry. Consequently, they are looking towards importing feedstock material and exporting the biofuel. This will create a limited number of jobs, but will be energy and carbon negative, and will not aid rural development. Currently there is no medium or large scale virgin oil to biofuel producer operating in the country and the start-up dates for projects are beyond 2013. The WVO biodiesel industry has grown rapidly in the last five years but is limited to small scale operators with limited benefit potential. With the exception of Brazil, other world leaders in biofuels are facing heavy criticism and the mechanisms used to initially boost the industry have very limited application in South Africa. The benefits of biofuel production in South Africa are plentiful and align well with social need and development goals. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.
5

An industry analysis of the South African biofuels industry

Cilliers, Bronwyn Lee January 2012 (has links)
Biofuels have been used as an energy source for heating and cooking since the beginning of time. However, recent changes in the demand for energy, and in particular, renewable energy, have spurred the growth of liquid biofuel industries in developed countries. Many developing countries, including South Africa have the potential to produce biofuels with benefits extending into the economic and social spheres. Despite government commitments and targets, the South African biodiesel and bio-ethanol industries have stalled in the starting blocks. This research aims to assess the reasons why. South Africa does not have the climate to compete with Brazil in bio-ethanol production and the scope for bioethanol is limited by environmental factors. However our neighbours show significantly more promise in this area. Biodiesel production is more likely to be commercially viable due to the country’s ability to grow oil crops and the need for the by-products. Despite the availability of land for cultivation of energy crops, the required technology and suitable infrastructure, progress has been slow. Uncertainty, high risk and misdirected government interventions have hampered investment in the sector and those involved in biofuel projects are very negative about the government’s ability to stimulate the industry. Consequently, they are looking towards importing feedstock material and exporting the biofuel. This will create a limited number of jobs, but will be energy and carbon negative, and will not aid rural development. Currently there is no medium or large scale virgin oil to biofuel producer operating in the country and the start-up dates for projects are beyond 2013. The WVO biodiesel industry has grown rapidly in the last five years but is limited to small scale operators with limited benefit potential. With the exception of Brazil, other world leaders in biofuels are facing heavy criticism and the mechanisms used to initially boost the industry have very limited application in South Africa. The benefits of biofuel production in South Africa are plentiful and align well with social need and development goals. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2013.
6

Desempenho de técnicas conservacionistas no controle da umidade, erosão hídrica e na produtividade do milho no semiárido pernambucano

BORGES, Tatyana Keyty de Souza 26 February 2013 (has links)
Submitted by (lucia.rodrigues@ufrpe.br) on 2016-10-14T11:56:08Z No. of bitstreams: 1 Tatyana Keyty de Souza Borges.pdf: 2480617 bytes, checksum: 7173e0074fec460be65b2ca9806e89e9 (MD5) / Made available in DSpace on 2016-10-14T11:56:08Z (GMT). No. of bitstreams: 1 Tatyana Keyty de Souza Borges.pdf: 2480617 bytes, checksum: 7173e0074fec460be65b2ca9806e89e9 (MD5) Previous issue date: 2013-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / This study aimed to investigate the performance of conservation techniques in experimental plots in the Ultisol abrúptico Eutrophic, to support planning and management of rainfed agriculture and availability of water resources in Pesqueira / PE. In additionally, it was determined the influence of mulching on soil and water losses by erosion in dystrophic Ultisol, using simulated rainfall in laboratory. This experiment was conducted with soil different from the previous due to the high cost of transporting the same. We performed the analysis of the dynamics of moisture and productivity of maize, considering natural rainfall in plots under different land cover types: bare soil (SD); growing corn vegetative drawstring with cactus, Opuntia ficus-indica Mill., (P) to form barriers to contain runoff, spaced 0.25 x 0.5 x 3.0 m, soil with natural cover (CN), corn cropped using stones, with approximately 8 cm high and 10 cm wide with 1 m distance between the rails, associated with mulch (BCM) and maize cultivation downhill (MA). Maize (Zea mays L.) in the period from April 14 to July 19 of the year 2011, and mulch used, available in the region, was the straw elephant grass (Pennisetum purpureum), with a density of 7 Mg ha -1, applied 20 days after sowing of maize. It was conducted biweekly monitoring of soil moisture, as well as biometrics culture. For the tests performed in the laboratory, used a rainfall simulator and experimental plots of dimensions 1.0 x 0.5 (0.5 m2), and 20 cm deep, with three replicates for each treatment, which were made 9 tests in total, with the absence and presence of mulch. The density of soil mulch, used the plots were 6 and 12 Mg ha-1 straw of sugar cane. Among the treatments evaluated in the field as well as in the laboratory, the mulch allowed greater control water erosion and maintaining humidity, to contribute to the process of water infiltration into the soil in relation to treatment with bare soil, and encourage the development maize under rainfed conditions. / Este trabalho visou investigar o desempenho de técnicas conservacionistas em escala de parcelas experimentais no Argissolo Amarelo Eutrófico abrúptico, como suporte ao planejamento e manejo da agricultura de sequeiro e disponibilidade de recursos hídricos, em Pesqueira/PE. Além disso, determinou-se a influencia do mulching nas perdas de solo e água por erosão hídrica, no Argissolo Amarelo Distrófico, utilizando chuva simulada em laboratório. Este experimento foi realizado com solo diferente do anterior devido ao custo elevado em transportar o mesmo. Foi realizada a análise da dinâmica da umidade e da produtividade da cultura do milho, considerando chuvas naturais, em parcelas sob diferentes tipos de cobertura do solo: solo descoberto (SD); cultivo de milho com cordão vegetativo com palma forrageira, Opuntia ficus-indica Mill. (P), de modo a formar barreiras para contenção do escoamento superficial, no espaçamento de 0,25 x 0,5 x 3,0 m; solo com cobertura natural (CN); cultivo do milho em nível com barramento em pedras, com aproximadamente 8 cm de altura e 10 cm de largura, com distância de 1 m entre os barramentos, associado com cobertura morta (BCM); e cultivo do milho morro abaixo (MA). O milho (Zea mays L.) foi cultivado no período de 14 de abril a 19 de julho do ano de 2011, e a cobertura morta utilizada, disponível na região, foi a palha de capim elefante (Pennisetum purpureum Schum), com densidade de 7 Mg ha-1, sendo aplicada 20 dias após o semeio do milho. Foram realizados monitoramentos quinzenais da umidade do solo, bem como biometria da cultura. Para os testes realizados em laboratório, utilizou-se um simulador de chuvas e parcelas experimentais de dimensões de 1,0 x 0,5 (0,5 m2), com 20 cm de profundidade, com três repetições para cada tratamento, no qual foram feitos 9 testes no total, com ausência e presença de cobertura morta. A densidade de cobertura morta do solo, usadas nas parcelas, foram de 6 e 12 Mg ha-1 de palha de cana-de-açúcar. Dentre os tratamentos avaliados em campo, como também em laboratório, a cobertura morta permitiu uma maior redução da erosão hídrica e manutenção da umidade, ao contribuir com o processo de infiltração da água no solo em relação ao tratamento com solo descoberto, e favorecer ao desenvolvimento do milho em regime de sequeiro.

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