• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 1
  • 1
  • Tagged with
  • 13
  • 13
  • 7
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 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.
11

Tecnologia alternativa para purificação do metano contido no biogás proveniente da digestão anaeróbica de dejetos de suínos / Alternative technology for purification of biogas obtained from swine manure

Possa, Rosangela Dala 06 February 2013 (has links)
Made available in DSpace on 2017-07-10T18:08:01Z (GMT). No. of bitstreams: 1 Rosangela Dala Possa.pdf: 2685580 bytes, checksum: 3b608d2924c5b2e0f11e3d8e887cdca5 (MD5) Previous issue date: 2013-02-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In recent years, the use of anaerobic bio-digestion systems for the treatment of wastes from agro-industrial activities has been intensified. The main products of bio-digestion are biogas and bio-fertilizer. Biogas is composed mainly of methane (CH4), carbon dioxide (CO2), hydrogen sulfide (H2S) and ammonia (NH3), which in most cases is used as fuel for powering stationary engines. In these cases, the presence of CO2, H2S and NH3, undermines the viability of its use as fuel because it reduces the calorific potential and lifetime of engines. In this context, the study aimed to develop and evaluate an alternative technology for purification of the methane contained in biogas from anaerobic digestion of swine manure. Therefore, the methodology contemplated the technological foresight inherent in matter (removal / purification of biogas), identifying advantages / disadvantages, design / construction of alternative technology (prototype) and its installation on a rural property for the purpose of operational testing. The results demonstrate the technical and economical viability for implementation in a real situation. For the corrosive components the reduction of 96% for H2S and of 83,1% for NH3 was achieved, beyond 6% CO2 reduction. The result was the increasing of methane concentration which reached 75% enabling the use of the biogas as a fuel. / Nos últimos anos, tem sido intensificado o uso de sistemas de biodigestão anaeróbica, para o tratamento dos dejetos das atividades agroindustriais. Os principais produtos da biodigestão são biogás e biofertilizante. O biogás é constituído, principalmente, de metano (CH4), dióxido de carbono (CO2), gás sulfídrico (H2S) e amônia (NH3), o qual, na maioria dos casos é utilizado como combustível para acionamento de motores estacionários. Nesses casos, a presença de CO2, H2S e NH3, comprometem a viabilidade do seu uso como combustível, pois reduz o potencial calorífico e a vida útil dos motores. Neste contexto, o trabalho teve como objetivo desenvolver e avaliar uma tecnologia alternativa para purificação do metano contido no biogás proveniente da digestão anaeróbica de dejetos de suínos. Para tanto, a metodologia contemplou a prospecção tecnológica inerente ao assunto (remoção/purificação de biogás), a identificação de vantagens/desvantagens, o projeto/construção da tecnologia alternativa (protótipo) e a sua instalação numa propriedade rural para efeitos de testes operacionais. Os resultados, demonstram a viabilidade técnica e econômica para implementação na situação real. Especificamente foi alcançada uma redução para os componentes corrosivos (96% para o H2S e 83,1% para a NH3), além de 6% de redução do CO2. A consequência disso foi o aumento da concentração do metano que atingiu 75% viabilizando a utilização do biogás como combustível.
12

Tecnologia alternativa para tratamento dos efluentes domésticos da área rural / Alternative technology for treatment of rural areas domestic sewage

Less, Diani Fernanda da Silva 14 February 2014 (has links)
Made available in DSpace on 2017-07-10T18:08:05Z (GMT). No. of bitstreams: 1 Diani Fernanda da Silva.pdf: 4308607 bytes, checksum: 15e7dca78e64eb979242f6e5eb152b6a (MD5) Previous issue date: 2014-02-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The use absence of domestic systems for wastewater treatment promotes the frequent cases of soil and water resources contamination, and contributes to the spread of diseases in the population. Within this context, the work aimed the development/proposition a methodology and alternative technology for treatment domestic sewage of residences located in rural area, specifically for the treatment of effluents generated in the kitchen sink and the toilet bowl. For this, was performed the domestic effluents source characterization through the management diagnostic of domestic wastewater in Paraná state and the city of Toledo; domestic effluents qualitative (physical, chemical and biological parameters) and quantitative (daily and monthly volume) characterization; performance evaluation of the conventional methods, processes and technologies for treatment of rural areas domestic sewage; the method and the technology design/developing for the rural domestic sewage treatment from the toilet bowl and kitchen sink; the construction, operation and monitoring of alternative technology; and the agreement analysis. From the results obtained in the first step, it was found that in Paraná state rural areas are generated over 261 thousand m³ day-1 of domestic sewage, in the city of Toledo rural area are produced 37,410.8 m3 of domestic effluent monthly. In the evaluation step of treatment methods and technologies it was verified the existence of technical limitations and bottlenecks in the equipment, prevailing the low treatment efficiency. Based on detailed studies of the physical, chemical and biological fundamentals and testing bench, was developed the project of alternative technology containing a feces and urine separator; a helical anaerobic bioreactor with tubular shape for the feces. The technology alternative prototype operation showed satisfactory results with respect the feces and urine separation and the feces stabilization in the reactor was completed in just 30 days of treatment forming a residual without the E. coli presence (<1 NMP g-1). / A ausência no uso de sistemas de tratamento de efluentes domésticos na área rural promove frequentes casos de contaminação do solo e dos recursos hídricos, bem como contribui com a disseminação de doenças entre a população. Nesse contexto, o objetivo do trabalho foi o desenvolvimento/proposição de uma tecnologia alternativa para o tratamento dos efluentes gerados no vaso sanitário e na pia da cozinha de residências da área rural. Para isso, realizou-se a caracterização da fonte geradora de efluentes domésticos por meio do diagnóstico da gestão dos efluentes doméstico no estado do Paraná e no município de Toledo; a caracterização quantitativa (volume diário e mensal) e qualitativa (parâmetros físicos, químicos e biológicos) dos efluentes domésticos; a avaliação do desempenho dos métodos, processos e tecnologias convencionais para o tratamento de efluentes domésticos das áreas rurais; o projeto/desenvolvimento do método e da tecnologia alternativa para o tratamento dos efluentes domésticos rurais provenientes do vaso sanitário e da pia da cozinha; a construção, operação e monitoramento da tecnologia alternativa; e a análise de concordância. A partir dos resultados obtidos na primeira etapa, constatou-se que nas áreas rurais do estado do Paraná são gerados mais de 261 mil m³. dia-1 de efluentes domésticos, na área rural da cidade de Toledo são produzidos 37410,8 m3 de esgoto domestico mensalmente. Na etapa de avaliação dos métodos e tecnologias de tratamento, constatou-se a existência de limitações e gargalos técnicos nos equipamentos, prevalecendo à baixa eficiência no tratamento. Com base em estudos detalhados dos fundamentos físicos, químicos e biológicos e dos testes de bancada, foi desenvolvido o projeto da tecnologia alternativa contendo um separador de fezes e urina, um biorreator anaeróbico helicoidal de formato tubular para o tratamento das fezes. A operação do protótipo da tecnologia alternativa apresentou resultados satisfatórios quanto a segregação das fezes e da urina e a estabilização dos dejetos no reator foi completa em apenas 30 dias de tratamento originando um composto sem a presença de E. coli (<1 NMP g-1).
13

Bränsle för den moderna nationen : Etanol och gengas i Sverige under mellankrigstiden och andra världskriget / Fuelling the Modern nation : Ethanol and Wood Gas as Alternative Fuels in Sweden during the Interwar Years and World War II

Ekerholm, Helena January 2012 (has links)
This thesis investigate Swedish policy-making concerning promotion of wood gas and ethanol distilled from fermented sulphite lye as domestic fuel alternatives in the Interwar years and World War II. With a departure point in the theories of social constructions of technology (SCOT), the sociology of expectations and Thomas P. Hughe’s socio-technical systems I analyse the measures that were undertaken in these efforts, the arguments put forward for and against the ethanol and wood gas projects and how the efforts turned out. I also investigate how the interpretations of ethanol and wood gas as fuel alternatives changed from the Interwar period on through World War II and what consequences this had for ethanol and wood gas policy immediately after World War II. Source material includes Parliament and Government records, cabinet meeting files, governmental commissions, authority archives, technical evaluations and handbooks and scientific medical publications. Ethanol and wood gas were promoted from a nationalist vantage point. The Interwar debate was imbued with visions of national techno-scientific prowess in a perceived ongoing global contest for technological and scientific advancement, of which achieving autarky, self-sufficiency on important raw materials and industrial products, was an ideal for some. Ethanol and wood gas were also promoted as means for creating a lucrative new market for the forestry industry, which also held a prominent position in nationalist visions of technology. Expectations of a new war also motivated the promotion of ethanol and wood gas as national fuels. Measures for promotion included tax exemptions, sales guarantees and legislation for mandatory ethanol purchase for all petrol importing companies and gasifier loan funds. Political conflicts mainly centred around the principles of free trade as opposed to protectionism, proper use of tax funds and whether the potentials of the fuel alternatives were rhetorically exaggerated. During World War II ethanol and wood gas in particular served as important petrol surrogates. The increased wood gas use led to negative interpretations of wood gas a fuel alternative due to its hazardous, dirty and time-consuming maintenance and the changed driving behaviour it required from its users compared to petrol or ethanol fuelled automobiles. Compared to wood gas, ethanol was appreciated for its socio-technical similarities to petrol, but production was after the war deemed difficult to maintain during wartime. Whereas wood gas remained an important stand-by surrogate during the cold war, Swedish politicians lost interest in ethanol of the kind that was promoted in the Interwar years. / Fuel of the Future? A Research Programme on the Science, Technology and Selling of Biofuels in Sweden

Page generated in 0.0897 seconds