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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.
11

Biomass Briquettes in Malawi

Faxälv, Olle, Nyström, Olof January 2007 (has links)
<p>In Malawi 2.5 % of the forest disappears each year. The use of firewood and charcoal, deriving from forest resources,</p><p>accounts for about 99 % of the household energy demand in Malawi and is a cause to the deforestation. The Government of</p><p>Malawi recently launched a programme called Promotion of Alternative Energy Sources Programme (PAESP) with the aim</p><p>to reduce the use of firewood and charcoal. One of the fuels included in the programme is the biomass briquette. The aim</p><p>with this study is to evaluate the viability of biomass briquettes as a sustainable alternative energy source to firewood and</p><p>charcoal for households in Malawi.</p><p>Research for the study was carried out during three months in Malawi. Visits were made to a number of briquette</p><p>production sites to study the manufacturing methods and to collect briquette samples. The briquettes were tested using</p><p>various methods and then compared with results for firewood and charcoal.</p><p>At the moment various production methods are used in Malawi, with a high difference in technical complexity and cost.</p><p>Machines produced from wood using very basic mechanics can apply similar pressure as more advanced metal pressers.</p><p>They also seem to be better suited than those made of metal, in terms of price and availability.</p><p>The majority of the briquette producers in Malawi use waste paper as base material. Although the paper briquettes are good,</p><p>other raw materials will be needed if the production is supposed to be significantly increased.</p><p>The briquettes burn well using the most common stoves in Malawi, including the commonly used charcoal stove. While</p><p>firewood is cheaper to use than other available fuels, the briquettes seem to be able to compete with the fuel costs for</p><p>charcoal.</p>
12

Biomass Briquettes in Malawi

Faxälv, Olle, Nyström, Olof January 2007 (has links)
In Malawi 2.5 % of the forest disappears each year. The use of firewood and charcoal, deriving from forest resources, accounts for about 99 % of the household energy demand in Malawi and is a cause to the deforestation. The Government of Malawi recently launched a programme called Promotion of Alternative Energy Sources Programme (PAESP) with the aim to reduce the use of firewood and charcoal. One of the fuels included in the programme is the biomass briquette. The aim with this study is to evaluate the viability of biomass briquettes as a sustainable alternative energy source to firewood and charcoal for households in Malawi. Research for the study was carried out during three months in Malawi. Visits were made to a number of briquette production sites to study the manufacturing methods and to collect briquette samples. The briquettes were tested using various methods and then compared with results for firewood and charcoal. At the moment various production methods are used in Malawi, with a high difference in technical complexity and cost. Machines produced from wood using very basic mechanics can apply similar pressure as more advanced metal pressers. They also seem to be better suited than those made of metal, in terms of price and availability. The majority of the briquette producers in Malawi use waste paper as base material. Although the paper briquettes are good, other raw materials will be needed if the production is supposed to be significantly increased. The briquettes burn well using the most common stoves in Malawi, including the commonly used charcoal stove. While firewood is cheaper to use than other available fuels, the briquettes seem to be able to compete with the fuel costs for charcoal.
13

Automatický kotel na pelety / Automatic boiler for biomass pellets

Sklenář, Vít January 2015 (has links)
The aim of this diploma thesis is the research of automatic boilers for biomass pellets and their burners, design of automatic boiler for biomass pellets which include calculation part and drawing part and technical-economics assessment for building in the end. Thesis is divided into four main parts. The first part deals with general information about pellets, automatic boilers for pellets, burners and the standard for boiler. In the second part the pellet boiler is calculated. In the third part the automatic pellet boiler is designed. The fourth section compares three possible variants. Comparison is done for economics and the user.
14

Šiaudų briketais kūrenamo katilo energetinių parametrų tyrimas / Research on energetic parameter of straw briquette fired boiler

Norkutė, Dovilė 02 June 2011 (has links)
Šiaudų briketais kūrenamo katilo energetiniai parametrai išnagrinėti magistrantūros baigiamajame darbe. Aptartas šiaudų, kaip kuro potencialas Lietuvoje, jų ištekliai bei panaudojimo galimybės kurui. Apžvelgtas šiaudų ruošimas kūrenimui, šiaudų kūrenimo būdai, įrenginiai, kurie gamina briketus, bei katilai kūrenami šiaudų briketais. Darbe yra pateikta šiaudų kuro sudėtis, kenksmingų medžiagų kiekiai, briketų energetinis efektyvumas ir ekonominė reikšmė. Tyrimo tikslas yra apskaičiuoti degimo proceso šiluminę galią, nustatyti katilo šiluminę galią, apskaičiuoti katilo efektyvumą esant skirtingai šiaudų briketų drėgmei bei masei. Į aplinką išmetamų kenksmingų emisijų nustatymas. Teoriškai ir eksperimentiškai ištyrus 10 kW galios katilą nustatyta, kad didžiausia katilo galia Pk prie 12 % šiaudų briketų drėgnio yra 23,17 kW, esant 14 % drėgniui, didžiausia katilo galia yra 15,99 kW, o esant 16 % drėgniui – 11,48 kW. Esant maksimaliam katilo efektyvumui, kai ηvid =77,2 %, katilo galia Pk yra 23,17 kW, o degimo proceso Pd galia padidėja iki 29,03 kW. Kai katilo naudingumo koeficientas yra maksimalus (ηvid =77,2 %), tada kuro sąnaudos siekia7 kg/h.Darbe pateikti šiaudų briketų deginimo tyrimų rezultatai. Tyrimų metu gauti ir apskaičiuoti rezultatai pateikti lentelėse, bei pavaizduoti grafiškai. / In the master’s thesis energetic parameters of the boiler heated by straw briquettes were analyzed. The potential of straw as a fuel in Lithuania, its resources and usage for fuel were discussed. The review of preparation of straw for heating, ways of heating with straw, equipment that makes briquettes and boilers heated by straw briquettes was performed. The paper presents the composition of straw fuel, the amounts of harmful materials, energetic efficiency of briquettes and economic significance. The aim of the research is to calculate the thermal power of the burning process, to define the thermal power of the boiler, to calculate the efficiency of the boiler at different humidity and mass of straw briquettes, to define the harmful emissions that affect the environment. Having analyzed theoretically and experimentally the boiler of 10 kW power, it was defined that the highest power Pk achieved at 12 % straw briquette humidity is 23,17 kW, when the humidity is 14 % , the highest power of the boiler is 15,99 kW, whereas at the 16 % humidity it is 11,48 kW. At the maximum power of the boiler, when ηvid =77,2 %, the power of the boiler Pk is 23,17 kW, the power of the burning process Pd reaches 29,03 kW. When the efficiency coefficient of the boiler is ultimate (ηvid = 55,3 %), the input of fuel reaches 7 kg/h. The paper presents the results of the research on burning straw briquettes. According to the results, different parameters mentioned in the research aims were... [to full text]
15

Kopplung von energetischer Verwertung und Aufbereitung von Biomassen - Erhöhung der Wirtschaftlichkeit

Nendel, Klaus, Clauß, Brit, Böttger, Uwe, Käferstein, Peter, Gohla, Matthias, Reimer, Hendrik, Tepper, Helmar, Neidel, Werner 30 October 2002 (has links) (PDF)
Zielstellung des Forschungsprojekts ist es, halm- und stengelförmige biogene Brennstoffe so zu einer handlings- und verkaufsfähigen Form mit hoher Energiedichte aufzubereiten, die für Verbrennungsanlagen kleinerer Leistung geeignet ist und gegenüber bisher verwendeten Brennstofformen, z.B. Häcksel, eine wesentliche Verbesserung des Abbrand-, Emissions- und Ascheverhaltens erreicht wird. Ein Funktionsmuster zur kontinuierlichen Aufbereitung von hochverdichteten, abriebfesten und formstabilen Briketts ist zu erstellen. In Kopplung mit Verbrennungsuntersuchungen werden die spezifischen Anforderungen an die Briketts abgeleitet und der Verfahrensablauf für die Aufbereitung optimiert. Bei der Erstellung eines Konzeptes für ein Demonstrationsobjekt für die zukünftige Verwertung von Biomassebriketts bildet die Wirtschaftlichkeit einen besonderen Schwerpunkt. Die Arbeiten zur Entwicklung des Brikettierverfahrens zeigen, daß eine Herstellung von stabilen Briketts aus Stroh oder Heu ohne zusätzliche Bindemittel möglich ist. Mit Hilfe experimenteller Untersuchungen konnten die erforderlichen Verfahrensparameter ermittelt werden. Um dauerhaft haltbare Briketts gleichbleibender Qualität herzustellen, muß das zu verarbeitende Halmgut unzerkleinert und mit einem Feuchtegehalt von 12 bis 15 % vorliegen. In der Verformung der unzerkleinerten Halme sowohl in Längsrichtung als auch in der Ebene des Stengelquerschnitts ist die Ursache für den Bindemechanismus in den Briketts zu finden. Unter Einwirkung von Preßdrücken von 100 bis 160 MPa liegt die Dichte der hergestellten Briketts je nach Gutart, bei 0,8 bis 1,2 g/cm3. Der Abriebanteil der Briketts, ermittelt nach ASAE S.269.4, liegt bei max. 5%. Ein Funktionsmuster zur Brikettierung (Brikettpresse mit vorgeschalteter Strangformungsstufe) für 25-mm - Briketts wurde konstruiert, gebaut und getestet. Mittels Elementar-, Immediat-, Chlor- und Schwermetallanalyse wurden die Eigenschaften für zehn verschiedene biogene Brennstoffe, vorwiegend Halmgüter (Getreide- und Rapsstroh, Wiesenheu, Miscanthus) charakterisiert. Die Abbranduntersuchungen der Briketts im Vergleich zum Häcksel zeigen, daß die Reaktionsphasen der Flüchtigenverbrennung und des Restkoksabbrandes gleichzeitig ablaufen. Eine wesentliche Verlängerung der Abbrandzeit ist zu verzeichnen, die mit zunehmender Brikettgröße und -dichte noch steigt. Während der gesamten Brennzeit werden die Schadstoffe gleichmäßig freigesetzt. Durch längere Verweilzeiten der Briketts im Reaktor wird der Kohlenstoffanteil des Brennstoffs vollständiger oxidiert, was sich in den wesentlich geringeren CO-Emissionen im Vergleich zum Häcksel widerspiegelt. Im Vergleich mit der TA Luft liegen die CO- und SO2-Emissionen der Biomassebriketts durchgängig unter den Grenzwerten. Durch eine luftgestufte Verfahrensführung (60% Primärluft, 40% Sekundärluft) ist es möglich, die NOx-Werte ebenfalls unter den Grenzwert der TA Luft abzusenken. Fallstudien zu möglichen Demonstrationsvorhaben belegen, daß eine wirtschaftliche Lösung für das Brikettieren in Verbindung mit einer energetischen Nutzung in kleinen Anlagen erreichbar ist. Die Leistung der Brikettieranlage bestimmt deutlich deren Wirtschaftlichkeit. Dabei muß eine Tagesproduktion von 8 bis 10 t erreicht werden (250 Betriebstage im Jahr). Gegenüber dem Funktionsmuster muß jedoch eine Vergrößerung des Brikettdurchmessers erfolgen.
16

Avaliação do potencial energético da biomassa de duas espécies de bambu cultivadas em Santa Catarina / Potential assesment of biomass energy two bamboo crops in Santa Catarina

Balduino Junior, Ailton Leonel 10 February 2016 (has links)
Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2017-12-06T15:51:14Z No. of bitstreams: 1 PGEF15MA054.pdf: 1294038 bytes, checksum: fababdbd931875c25f9cf6033b6c6963 (MD5) / Made available in DSpace on 2017-12-06T15:51:14Z (GMT). No. of bitstreams: 1 PGEF15MA054.pdf: 1294038 bytes, checksum: fababdbd931875c25f9cf6033b6c6963 (MD5) Previous issue date: 2016-02-10 / The aim of this study was to evaluate the energy potential of biomass of two species of bamboo from briquettes, coal and culms in natura. The species analyzed were: Bambusa vulgaris and Phyllostachys bambusoides with three years old. selected were 5.0 individuals of each species and collected portions of 1.0 m to 1.5 m long at the base, middle and top of the stems. The Bambusa vulgaris was collected at the Experimental Farm Ressacada the Federal University of Santa Catarina, Florianópolis, SC. The Phyllostachys bambusoides was collected in Fomio Honda property in Frei Rogério - SC. In culms in natura we were determined moisture content properties (TU); Basic density (DB); particle size (L); power higher calorific (PCS); immediate analysis (AI) and chemical composition (AQ). The bamboo was carbonized in the laboratory, and coal was analyzed for gravimetric yield (RG); moisture content (TU), bulk density (DA); power higher calorific (PCS) and immediate analysis (AI). The briquettes were made in hydraulic briquetter laboratory and analyzed properties were apparent density (AD) and compressive strength (RC). With the results we calculated the energy density (DE) for each product type and compared the best way to use species for the generation of energy. The culms of Bambusa vulgaris and Phyllostachys bambusoides had TU 39% and 36 %; DB 0.624 and 0.719 g / cm3 ; volatile content (TV ) of of 82.25% and 81.88%; fixed carbon (FC) 15.26% and 17.28%; ash content (CT) 2.49% 0 and 90%; and PCS 4571 and 4694 kcal / kg, respectively. The extractives content was 16.26% and 16.24% and the lignin content of 25.76% and 25.54, respectively. Charcoal had RG 36.40% and 33.35%; DA 0.372 and 0.367 g / cm³; TV 27.55% and 27.26%; CF of 67.32% and 31.09%; CT 5.12% and 1.65%, and PCS 7431 and 7587 kcal / kg, respectively. The briquettes were DA 1111 and 1170 kg / m³, and RC 4,961 and 4,677 MPa respectively. DE The culms was 11.91 and 14.14 MJ / m³. For coal of 11.60 and 11.66 MJ / m³, and the briquettes 21.31 and 22.99 MJ / m³, respectively. Bamboo species have similar quality for power generation. The species Phyllostachys bambusoides proved better than Bambusa vulgaris species in use in natura. Increased energy efficiency bamboo use was in the form of briquettes, followed by the use in nature, and later in the form of charcoal / O objetivo deste estudo foi avaliar o potencial energético da biomassa de duas espécies de bambu a partir de briquetes, carvão e colmos in natura. As espécies analisadas foram: Bambusa vulgaris e Phyllostachys bambusoides, com três anos de idade. Foram selecionados 5,0 indivíduos de cada espécie e coletadas porções de 1,0 m a 1,5 m de comprimento na base, no meio e no topo dos colmos. O Bambusa vulgaris foi coletado na Fazenda Experimental Ressacada da Universidade Federal de Santa Catarina, em Florianópolis, SC. O Phyllostachys bambusoides foi coletado na propriedade de Fomio Honda, em Frei Rogério – SC. Nos colmos in natura foram determinadas as propriedades de teor de umidade (TU); densidade básica (DB); granulometria (G); poder calorífico superior (PCS); análise imediata (AI) e composição química (AQ). O bambu foi carbonizado em laboratório, e o carvão foi analisado quanto ao rendimento gravimétrico (RG); teor de umidade (TU), densidade aparente (DA); poder calorífico superior (PCS) e análise imediata (AI). Os briquetes foram confeccionados em briquetadeira hidráulica de laboratório, e as propriedades analisadas foram: densidade aparente (DA) e resistência à compressão (RC). Com os resultados obtidos foi calculada a densidade energética (DE) para cada tipo de produto e comparada a melhor forma de utilização das espécies para a geração de energia. Os colmos de Bambusa vulgaris e Phyllostachys bambusoides tiveram TU de 39%, e 36%; DB de 0,624, e 0,719 g/cm3; teor de voláteis (TV) de 82,25%, e 81,88%; teor de carbono fixo (CF) de 15,26% e 17,28%; teor de cinzas (TC) de 2,49% e 0 90%; e PCS de 4571 e 4694 kcal/kg, respectivamente. O teor de extrativos totais foi de 16,26% e 16,24% e o teor de lignina de 25,76% e 25.54, respectivamente. O carvão vegetal teve RG de 36,40% e 33,35%; DA de 0,372 e 0,367 g/cm³; TV de 27,55% e 27,26%; CF de 67,32% e 31,09%; TC de 5,12% e 1,65% e PCS de 7431 e 7587 kcal/Kg, respectivamente. Os briquetes tiveram DA de 1111 e 1170 kg/m³, e RC 4,961 e 4,677 Mpa, respectivamente. A DE do colmos foi de 11,91 e 14,14 MJ/m³; para o carvão de 11,60 e 11,66 MJ/m³, e para os briquetes de 21,31 e 22,99 MJ/m³, respectivamente. As espécies de bambu possuem qualidade similar para geração de energia. A espécie Phyllostachys bambusoides mostrou-se melhor que a espécie Bambusa vulgaris no uso in natura. A maior eficiência energética do uso do bambu foi na forma de briquete, seguido do uso in natura, e posteriormente na forma de carvão vegetal
17

Quantificação e caracterização físico-química do material particulado fino (MP2,5): queima de biomassa em fornos de pizzaria na cidade de São Paulo / The chemical quantification and characterization of fine particulate mass (PM2,5): the burning of biomasses in pizza ovens within the city of São Paulo

Lima, Francisco Daniel Mota 14 July 2015 (has links)
A queima de biomassa em fornos de pizzaria se constitui como importante fonte de poluição do ar. Entre outros tipos de poluentes emitidos, o material particulado finoMP2,5 se destaca como o mais agressivo à saúde humana, além de poder interferir no balanço radiativo global. Objetiva-se, desta forma, através de estudo de caso em três pizzarias na cidade de São Paulo, quantificar e caracterizar o MP2,5 emitido pela queima da biomassa na área interna (indoor) e externa (junto á chaminé). Dentre as três pizzarias, duas fazem uso da lenha de eucalipto e a outra faz uso do briquete, formado a partir da compactação de pedaços de biomassa, serragem, bagaço e outros resíduos madeireiros. As amostras foram coletadas utilizando-se o amostrador Minivol. A análise do material foi realizada por meio de técnicas complementares: gravimetria (para a concentração em massa), refletância (para a concentração de black carbon), fluorescência de raios-X (para a concentração elementar) e utilização do microscópio eletrônico de varredura (MEV) (para identificar a morfologia do material particulado). Além disso, foram feitas inferências na saúde do trabalhador quanto á exposição ao MP2,5, e por fim foi estimada as emissões de MP2,5 e black carbon dado o elevado número de pizzarias existentes na cidade de São Paulo. Os resultados apresentaram concentrações médias elevadas de MP2,5, 6171,14 g/m3 no ambiente externo, e 68,24 g/m3 no ambiente interno para as três pizzarias. A queima do briquete apresentou menores concentrações para MP2,5. Os elementos químicos potássio, cloro e enxofre foram os mais representativos em termos de concentração. Os resultados para o MEV revelaram partículas com morfologia esférica individual, conglomerado de partículas esféricas, partículas achatadas com o formato de fibras, sobreposição de camadas e aglomerados de partículas com aspecto esponjoso. Embora no Brasil não exista padrão de exposição para o MP2,5 em ambiente interno, quando comparado com o padrão de exposição da Alemanha, as concentrações obtidas nas três pizzarias são superiores. Concentrações em massa de elementos prejudiciais à saúde como o cromo e zinco se mostraram demasiadamente elevadas. Os fatores de emissão para o MP2,5 e black carbon provenientes da queima da lenha foram 0,38g/kg e 0,23g/kg, respectivamente; e para o briquete 1,04g/kg e 0,37g/kg respectivamente. As emissões de MP2,5 e black carbon foram de 0,958t/ano e 0,340t/ano para a queima do briquete e 116,736t/ano e 70,656t/ano para a queima da lenha / The burning of biomass in pizza ovens constitutes itself as an important source of air pollution. Compared with other types of pollutants emitted, the fine particulate matter PM2,5 highlights itself as one of the most aggressive to human health, besides the power to interfere with global radiative balance. Therefore, through the study of three São Paulo pizzerias, the quantification and characterization of PM2,5 emitted by the burning of biomass within internal areas and external (where chimney´s were present). Among the three pizzerias, two used eucalyptus timber logs while the remaining other used wooden briquettes; formed by the compression of biomass: chips and shavings and other wood residue. Samples were collected using Minivol. The analysis of the material was completed via complementary techniques: gravimetrically (to establish mass concentration) Reflectance (to establish black carbon concentration) X-ray fluorescence (to establish element concentration) and the use of an electro-microscopic sweep (SEM) (to indentify the morphology of the particulate matter). Beyond this, inferences were made about the health of workers exposed to PM2,5, by way of estimated emissions of PM2,5 due to the elevated number of pizzerias in São Paulo. The results from the three pizzerias revealed elevated average concentrations of PM2,5, 6171,14 g/m3 in external areas and 68,24 g/m3 in internal areas. The burning of briquette revealed lower concentrations of PM2,5. The chemical elements: potassium, chlorine and sulfur were the most represented in terms of concentration. The results of the SEM (electro-microscopic sweep) revealed particles with an individual and spherical morphology, the conglomeration of spherical particles, flattened particles in the formation of fibers, the overlapping of layers and the clustering of particles with sponge-like qualities. Although in Brazil there are no existing parameters for PM2,5 exposure in internal areas, when compared with the established exposure parameters in Germany, the concentrations obtained within the three pizzerias exceeded those parameters. Concentration en masse of elements dangerous to health such as chrome and zinc were shown to be excessive. The rate of emissions of PM2,5 and black carbon due to the burning of logs were 0,38g/kg and 0,23g/kg, respectively; and for briquettes were 1,04g/kg and 0,37g/kg, respectively. The emissions of PM2,5 and black carbon were from 0,958t/year to 0,340t/year in the burning of briquettes and from 116,736t/year to 70,656t/year in the burning of timber logs
18

Quantificação e caracterização físico-química do material particulado fino (MP2,5): queima de biomassa em fornos de pizzaria na cidade de São Paulo / The chemical quantification and characterization of fine particulate mass (PM2,5): the burning of biomasses in pizza ovens within the city of São Paulo

Francisco Daniel Mota Lima 14 July 2015 (has links)
A queima de biomassa em fornos de pizzaria se constitui como importante fonte de poluição do ar. Entre outros tipos de poluentes emitidos, o material particulado finoMP2,5 se destaca como o mais agressivo à saúde humana, além de poder interferir no balanço radiativo global. Objetiva-se, desta forma, através de estudo de caso em três pizzarias na cidade de São Paulo, quantificar e caracterizar o MP2,5 emitido pela queima da biomassa na área interna (indoor) e externa (junto á chaminé). Dentre as três pizzarias, duas fazem uso da lenha de eucalipto e a outra faz uso do briquete, formado a partir da compactação de pedaços de biomassa, serragem, bagaço e outros resíduos madeireiros. As amostras foram coletadas utilizando-se o amostrador Minivol. A análise do material foi realizada por meio de técnicas complementares: gravimetria (para a concentração em massa), refletância (para a concentração de black carbon), fluorescência de raios-X (para a concentração elementar) e utilização do microscópio eletrônico de varredura (MEV) (para identificar a morfologia do material particulado). Além disso, foram feitas inferências na saúde do trabalhador quanto á exposição ao MP2,5, e por fim foi estimada as emissões de MP2,5 e black carbon dado o elevado número de pizzarias existentes na cidade de São Paulo. Os resultados apresentaram concentrações médias elevadas de MP2,5, 6171,14 g/m3 no ambiente externo, e 68,24 g/m3 no ambiente interno para as três pizzarias. A queima do briquete apresentou menores concentrações para MP2,5. Os elementos químicos potássio, cloro e enxofre foram os mais representativos em termos de concentração. Os resultados para o MEV revelaram partículas com morfologia esférica individual, conglomerado de partículas esféricas, partículas achatadas com o formato de fibras, sobreposição de camadas e aglomerados de partículas com aspecto esponjoso. Embora no Brasil não exista padrão de exposição para o MP2,5 em ambiente interno, quando comparado com o padrão de exposição da Alemanha, as concentrações obtidas nas três pizzarias são superiores. Concentrações em massa de elementos prejudiciais à saúde como o cromo e zinco se mostraram demasiadamente elevadas. Os fatores de emissão para o MP2,5 e black carbon provenientes da queima da lenha foram 0,38g/kg e 0,23g/kg, respectivamente; e para o briquete 1,04g/kg e 0,37g/kg respectivamente. As emissões de MP2,5 e black carbon foram de 0,958t/ano e 0,340t/ano para a queima do briquete e 116,736t/ano e 70,656t/ano para a queima da lenha / The burning of biomass in pizza ovens constitutes itself as an important source of air pollution. Compared with other types of pollutants emitted, the fine particulate matter PM2,5 highlights itself as one of the most aggressive to human health, besides the power to interfere with global radiative balance. Therefore, through the study of three São Paulo pizzerias, the quantification and characterization of PM2,5 emitted by the burning of biomass within internal areas and external (where chimney´s were present). Among the three pizzerias, two used eucalyptus timber logs while the remaining other used wooden briquettes; formed by the compression of biomass: chips and shavings and other wood residue. Samples were collected using Minivol. The analysis of the material was completed via complementary techniques: gravimetrically (to establish mass concentration) Reflectance (to establish black carbon concentration) X-ray fluorescence (to establish element concentration) and the use of an electro-microscopic sweep (SEM) (to indentify the morphology of the particulate matter). Beyond this, inferences were made about the health of workers exposed to PM2,5, by way of estimated emissions of PM2,5 due to the elevated number of pizzerias in São Paulo. The results from the three pizzerias revealed elevated average concentrations of PM2,5, 6171,14 g/m3 in external areas and 68,24 g/m3 in internal areas. The burning of briquette revealed lower concentrations of PM2,5. The chemical elements: potassium, chlorine and sulfur were the most represented in terms of concentration. The results of the SEM (electro-microscopic sweep) revealed particles with an individual and spherical morphology, the conglomeration of spherical particles, flattened particles in the formation of fibers, the overlapping of layers and the clustering of particles with sponge-like qualities. Although in Brazil there are no existing parameters for PM2,5 exposure in internal areas, when compared with the established exposure parameters in Germany, the concentrations obtained within the three pizzerias exceeded those parameters. Concentration en masse of elements dangerous to health such as chrome and zinc were shown to be excessive. The rate of emissions of PM2,5 and black carbon due to the burning of logs were 0,38g/kg and 0,23g/kg, respectively; and for briquettes were 1,04g/kg and 0,37g/kg, respectively. The emissions of PM2,5 and black carbon were from 0,958t/year to 0,340t/year in the burning of briquettes and from 116,736t/year to 70,656t/year in the burning of timber logs
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Barreiras ao avanço do consumo de briquetes de resíduos de madeira em pizzarias da região de São José dos Campos

Pontieri, Caroline Schreiber do Nascimento 15 June 2018 (has links)
Submitted by Caroline Schreiber do Nascimento Pontieri (carol_schnascimento@hotmail.com) on 2018-06-18T18:56:59Z No. of bitstreams: 1 TA_caroline_schreiber_pontieri_vf_pos_banca_v3.pdf: 2031675 bytes, checksum: 096a9d2f00d3ba9d6803186c36499722 (MD5) / Approved for entry into archive by Simone de Andrade Lopes Pires (simone.lopes@fgv.br) on 2018-06-19T00:27:24Z (GMT) No. of bitstreams: 1 TA_caroline_schreiber_pontieri_vf_pos_banca_v3.pdf: 2031675 bytes, checksum: 096a9d2f00d3ba9d6803186c36499722 (MD5) / Approved for entry into archive by Isabele Garcia (isabele.garcia@fgv.br) on 2018-06-19T16:07:52Z (GMT) No. of bitstreams: 1 TA_caroline_schreiber_pontieri_vf_pos_banca_v3.pdf: 2031675 bytes, checksum: 096a9d2f00d3ba9d6803186c36499722 (MD5) / Made available in DSpace on 2018-06-19T16:07:52Z (GMT). No. of bitstreams: 1 TA_caroline_schreiber_pontieri_vf_pos_banca_v3.pdf: 2031675 bytes, checksum: 096a9d2f00d3ba9d6803186c36499722 (MD5) Previous issue date: 2018-06-15 / A matriz energética mundial vem evoluindo, e novas alternativas em relação às energias renováveis também – principalmente a solar e a eólica. O Brasil também segue essa tendência. Por outro lado, há outras fontes de energia renováveis que têm grande potencial para desenvolvimento no Brasil. Neste estudo, analisam-se o mercado do briquete de madeira - feito a partir de resíduos de madeira (pó de serra, cavaco e maravalha), além de poda de árvore - na região de São José dos Campos (SP) e as barreiras enfrentadas nesse mercado. Tais barreiras foram mapeadas inicialmente por pesquisadores, e aqui é feita uma análise junto aos principais stakeholders envolvidos. Para isso, foi realizada uma pesquisa quantitativa com o uso do método pesquisa-ação, através do qual se identificou que as barreiras Agrícola e Florestal não têm um grande destaque para os envolvidos; que não existem também muitos dados relativos ao mercado de briquetes e que, na barreira Institucional, há falta de organização do setor. Questões relacionadas às barreiras Culturais, Educacionais e Tecnológicas tiveram destaque especial neste estudo. Uma reflexão da pesquisadora a ser salientado é que a barreira Ambiental não tem apresentado grande destaque para os envolvidos, mas, sim, questões financeiras – seja para o investidor ou proprietários das pizzarias. Da mesma forma, recomendam-se pesquisas para disponibilizar ao setor dados, além de cursos para buscar a profissionalização do/no setor – que é extremamente carente de recursos especializados. A utilização de resíduos de serrarias (pó de serra) também teve destaque, pois não se sabia que havia tão alta disponibilidade de matéria-prima no mercado. Por fim, identifica-se que o briquete tem grande potencial de desenvolvimento no setor, apesar das barreiras mapeadas. / The world energy matrix has been evolving, and new alternatives in relation to renewable energies too – mainly solar and wind. Brazil also follows this trend. On the other hand, there are other sources of renewable energy which have a great potential for Brazil’s development. In this study, the wood briquette is analyzed, made from wood waste (sawdust, wood chips and wood shaving), besides trees pruning – in the region of São José dos Campos (SP) and the barriers faced in this market. Such barriers have been initially mapped by researchers, and here an analysis is made along with the main stakeholders involved. In order to do this, a quantitative research has been carried out with the research- action method, in which it has been identified that agricultural and forestry barriers do not have a great highlight for those involved; also, there is not much data relating to the briquette market and, in the Institutional barrier, there is a lack of organization in the sector. Issues related to Cultural, Educational and Technological barriers have had a great emphasys in this study. A researcher’s consideration to be highlighted is that the Environmental barrier has not presented great prominence for those involved, but rather financial issues– either for the investor or pizzeria owners. Likewise, researches are recommended to provide data to the sector, as well as courses to seek the professionalization in the sector – which is extremely lacking in specialized resources. The use of sawmill waste (sawdust) also has had a prominent position, because it has not been known there was such a high availability of raw material in the market. Finally, it has been identified that the briquette has a great development potential in the sector, despite the barriers mapped.
20

Limiting phenomena related to the use of iron ore pellets in a blast furnace

Kemppainen, A. (Antti) 03 November 2015 (has links)
Abstract Most of the iron in the world is produced using a blast furnace process, which has iron ore (iron oxides) and coke as its raw materials. When pellets are used in a blast furnace, the iron burden material is charged in the form of pellets and fine, iron-rich by-products are charged typically in the form of cold-bonded briquettes at the top of the blast furnace. Coke is the primary fuel and reductant in the blast furnace. Coke reacts with the oxygen of the blast air and forms carbon monoxide in the up-flowing gas, which reduces the descending iron oxide burden. In addition, carbon and hydrogen bearing reductants are injected from the tuyeres in the lower part of the furnace. Hydrogen partially replaces the carbon monoxide as a reducing agent and changes the composition of the reducing gas. The high temperature properties of the burden have a significant effect on the flow of reducing gas and formation of the cohesive zone which markedly affect the furnace efficiency. The raw materials are commonly stored outdoors and therefore include moisture in varying amounts. In addition, the briquette contains chemically bound water. The rate of injected reductants, the high temperature properties and the water content of the raw materials have significant effects on blast furnace performance. They cause various phenomena in the blast furnace which set limitations on the process. The limiting phenomena related to the use of pellets in the blast furnace were studied in this doctoral thesis with the aim of obtaining additional knowledge about the limiting phenomena. The results show that hydrogen increases the reduction rate of iron oxides at temperatures below 850 °C. High water vapour concentration causes a rapid conversion through a catalysed water-gas shift reaction at above 300 °C in a gas mixture similar to the one in the upper part of the blast furnace. The reduction rate of the cold-bonded briquette is higher than pellets due to a self-reducing effect. The phase transformations occurring in the briquette during reduction follow the path of phase equilibria. The softening of the pellet is caused by the formation of melt which initiates wüstite dissolution in the surrounding slag phase. / Tiivistelmä Suurin osa maailmassa valmistettavasta raudasta tuotetaan masuuniprosessilla, jonka pääraaka-aineita ovat rautarikaste eli raudan oksidit ja koksi. Masuunissa, jossa käytetään pellettiä, rautarikaste panostetaan pelletin muodossa ja hienojakeiset rautapitoiset sivutuotteet tyypillisesti kylmäsidottuna brikettinä masuunin huipulta. Koksi on masuunin pääasiallinen polttoaine ja pelkistin, joka masuunin sisään puhallettavan ilman hapen kanssa reagoidessaan muodostaa ylöspäin virtaavaan kaasuun hiilimonoksidia, joka pelkistää masuunin kuilussa vajoavat rautaoksidit. Lisäksi yleensä käytetään hiiltä ja vetyä sisältäviä pelkistysaineita, jotka injektoidaan masuuniin alaosan hormeilta. Vety korvaa osittain hiilimonoksidia rautaoksidien pelkistimenä ja muuttaa pelkistävän kaasun koostumusta. Panosmateriaalien korkealämpötilaominaisuudet vaikuttavat suuresti kuilun kaasuvirtauksiin ja koheesiovyöhykkeen muodostumiseen masuunissa, mitkä vaikuttavat merkittävästi masuunin tehokkuuteen. Suurista määristä johtuen raaka-aineet varastoidaan usein ulkona, joten ne sisältävät kosteutta vaihtelevissa määrin. Lisäksi briketti sisältää kemiallisesti sitoutunutta vettä. Injektoitavien pelkistysaineiden käyttömäärällä, raaka-aineiden korkealämpötilaominaisuuksilla ja vesipitoisuudella on merkittäviä vaikutuksia masuunin toimintaan. Ne aikaansaavat masuunissa erilaisia ilmiöitä, jotka asettavat prosessille rajoituksia. Tässä väitöskirjassa tutkittiin näitä masuunille rajoituksia asettavia ilmiöitä ja pyrittiin lisäämään tietämystä niistä. Tulokset osoittavat, että vety nopeuttaa rautaoksidien pelkistymistä alle 850 °C lämpötilassa. Suuri vesihöyrymäärä johtaa nopeaan konversioon masuunin yläkuilun aluetta vastaavassa kaasuseoksessa yli 300 °C lämpötilassa katalysoidun vesikaasun siirtoreaktion kautta. Kylmäsidottu briketti pelkistyy pellettiä nopeammin itsepelkistymisen vaikutuksesta. Briketin pelkistyessään läpikäymät faasitransformaatiot seuraavat faasien tasapainotiloja. Pelletin pehmenemisen aiheuttaa sulan muodostuminen, joka laukaisee wüstiitin liukenemisen sitä ympäröivään sulaan kuonafaasiin.

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