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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

Measurement of gas evolution from PUNB bonded sand as a function of temperature

Samuels, Gregory James 01 July 2011 (has links)
The chemical binders used to make sand molds and cores thermally decompose and release gas when subjected to the high temperature conditions in sand casting processes. Computational models that predict the evolution of the binder gas are being introduced into casting simulations in order to better predict and eliminate gas defects in metal castings. These models require knowledge of the evolved binder gas mass and molecular weight as a function of temperature, but available gas evolution data are limited. In the present study, the mass and molecular weight of gas evolved from PUNB bonded sand are measured as a function of temperature for use with binder gas models. Thermogravimetric analysis of bonded sand is employed to measure the binder gas mass evolution as a function of temperature for heating rates experienced in molds and cores during casting. The volume and pressure of gas evolved from bonded sand are measured as a function of temperature in a specially designed quartz manometer during heating and cooling in a furnace. The results from these experiments are combined with the ideal gas law to determine the binder gas molecular weight as a function of temperature. Thermogravimetric analysis reveals that the PUNB binder significantly decomposes when heated to elevated temperatures, and the PUNB binder gas mass evolution is not strongly influenced by heating rate. During heating of PUNB bonded sand at a rate of 2°C/min, the binder gas molecular weight rapidly decreases from 375 g/mol at 115°C to 99.8 g/mol at 200°C. The molecular weight is relatively constant until 270°C, after which it decreases to 47.7 g/mol at 550°C. The molecular weight then steeply decreases to 30.3 g/mol at 585°C and then steeply increases to 47.2 g/mol at 630°C, where it remains constant until 750°C. Above 750°C, the binder gas molecular weight gradually decreases to 33.3 g/mol at 898°C. The present measurements are consistent with the molecular weights calculated using the binder gas composition data from previous studies. The binder gas is composed of incondensable gases above 709°C, and the binder gas partially condenses during cooling at 165°C if the bonded sand is previously heated below 507°C.
12

The Influence of Rolling Oil Decomposition Deposits on the Quality of 55Al-43.4Zn-1.6Si Alloy Coatings

Pillar, Rachel Joanne, rachel.pillar@flinders.edu.au January 2007 (has links)
Uncoated defects in hot dip metal-coated steel products result from non-wetting of the steel surface by the molten alloy. The occurrence of uncoated defects is highly detrimental to product quality and production efficiency; uncoated defects compromise the appearance and anti-corrosion performance of hot dip metal-coated steel products and causes time delays in the application of subsequent surface treatments. Although many studies have been directed towards evaluating the effect of steel pre-heat temperature and oxidation on the formation of uncoated defects, fewer investigations have analysed how oil-derived residues remaining on steel surface following the cold rolling and furnace cleaning processes impact upon hot dip metallic coating quality. Furthermore, although a considerable amount of research has focussed on the process of deposit formation in lubricants used in other applications, the composition of oily residues remaining after the continuous annealing process, and the origins of these residues in the original rolling oil formulation, are poorly understood. The primary focus of the present work has been to gain an improved understanding of relationships between cold rolling oil composition, oil residue-formation characteristics and the occurrence of uncoated defects in 55Al-43.4Zn-1.6Si hot dip metallic coatings. Several key classes of rolling oil ingredients which decompose to leave high levels of thermally-stable residue have been identified. The thermal decomposition processes undergone by a variety ingredients within these classes have been studied under both oxidising and reducing conditions using Thermogravimetric Analysis (TGA) and Pressure Differential Scanning Calorimetry (PDSC) techniques, with chemical characterisation of the decomposition process and the resultant thermally-stable residue by infrared spectroscopy. Model blends of each ingredient in a typical cold rolling oil base ester have also been evaluated by TGA and PDSC to identify the impact of ingredient concentration and chemical structure on the amount of oily residue formed. The results of these investigations have been related to the impact of the ingredients on 55Al-43.4Zn-1.6Si hot dip metallic coating quality through the performance of industrial-scale hot dipping trials and hot dip simulation studies. In order to translate these results into a context more closely aligned with industrial conditions, the effect of processing variables, including furnace atmosphere and the availability/concentration of iron in contact with the rolling oil at the steel surface, on the decomposition process of a fully-formulated commercial cold rolling oil has also been investigated. The information gained can potentially be used to tailor operating conditions within the cold rolling/continuous hot dip metallic coating processes to enhance steel surface cleanliness. Finally, the deposit-forming tendencies of an array of different commercial cold rolling oils have been evaluated, leading to the development of a thermal analysis-based test for screening cold rolling oils with respect to their likely impact upon 55Al-43.4Zn-1.6Si hot dip metallic coating quality. This test, together with the understanding obtained on the effect of different rolling oil ingredients on hot dip metallic coating quality, can be used within the industry to formulate improved cold rolling oils.
13

Adsorption and Desorption of Mercury Chloride on Sulfur-impregnated Activated Carbon by Thermogravimetric Analysis (TGA)

Syue, Sheng-Han 27 August 2008 (has links)
This study investigated the adsorptive and desorption capacity of HgCl2 onto powdered activated carbon derived from carbon black of pyrolyzed waste tires (CPBAC) via thermogravimetric analysis (TGA). Due to incomplete classification and recycling of municipal solid wastes (MSW), they still mix with a lot of hazardous materials, which unfortunately can not be removed by incinerators and air pollution control devices(APCDs). Among them, mercury and its pollutants attract more attention by people. Mercury and its pollutants emitted from the incineration of municipal solid wastes could cause severely adverse effects on human health and ecosystem since they exist mainly in vapor phase due to high vapor pressure. If they can not be remove by the air pollution control devices, they will be emitted to the atmosphere and cause serious effects on environmental ecology via various routes. Activated carbon has been widely applied to the treatment of organic compounds and heavy metals in wastewater and waste gas stream. However, the adsorptive capacity of activated carbon decreases with adsorption temperature. The low adsorptive capacity of activated carbon at high temperature (>150 oC) can be overcome by impregnated activated carbons. Previous study reported that sulfur impregnated powdered activated carbons could effectively remove the vapor-phase elemental mercury (Hgo) emitted from MSW incinerators and utility power plants. However, the impregnated typically used is sulfur (S) which is solely applied for the adsorption of elemental mercury (Hgo). Besides, these studies seldom investigate the distribution of impregnated sulfur in the inner pores of activated carbon and its effects on the specific surface area and pore size distribution. Thus, this study was to investigate the fundamental mechanisms for the adsorption/desorption of HgCl2 by/from sulfur impregnated PAC. Experimental results indicated that the sulfur content of sulfur impregnated CBPAC decreased with increasing impregnation temperatures form 400 to 650 oC; while the surface area of sulfur impregnated CBPAC increased with impregnation temperatures. In this study, TGA was applied to obtain the adsorptive capacity of HgCl2 onto CBPAC with adsorption temperature (150oC) and influent HgCl2 concentration (100~500 £gg/m3). Experimental results indicated that the adsorptive capacity of CBPAC increased with the increase of influent HgCl2 concentration and surface area of the activated carbon. This study revealed that the impregnation of sulfur on CBPAC could increase its adsorption capacity at high temperatures. Desorption experimental parameters included desorption temperature (400, 500, and 600 oC), heating rate (10, 15, and 20 oC /min) and regeneration cycle (1~7 cycles). In probing into the regeneration efficiency of CBPAC, experiments were conducted at the desorption times of 60 and 30 min. The results suggested the regeneration efficiency of carbon under 30 min was generally highter than that under 60 min. Because the desorption time was more longer and the sulfur content was lesser. Therefore, the regeneration times was reduce. Experimental results indicated that the mechanism of HgCl2 desorption from the spent CPBAC was strongly affected by desorption temperature. Both the desorption efficiency and the desorption rate of HgCl2 increased dramatically with desorption temperature. The desorption heat of HgCl2 (823 KJ/mole) was much higher than the vaporization heat of HgCl2 (59.2 KJ/mole), indicating that the adsorption of HgCl2 on sulfur impregnated CBPAC was chemical adsorption. Consequently, raising desorption temperature could enhance the desorption of HgCl2 and shorten the duration for HgCl2 desorption. Moreover, the formation of HgS during the desorption of HgCl2 from activated carbons can be proved by the surface characteristics of sulfur impregnated activated carbons. Results obtained from the regeneration of sulfur impregnated activated carbons indicated that the regeneration cycles decreased as the desorption duration increased. It was attributed to the potential desorption of sulfur from actived carbons, which thus decreased the adsorptive capacity and the regeneration cycles.
14

Experimental Investigation of the Effects of Fuel Properties on Combustion Performance and Emissions of Biomass Fast Pyrolysis Liquid-ethanol Blends in a Swirl Burner

Moloodi, Sina 14 December 2011 (has links)
Biomass fast pyrolysis liquid, also known as bio-oil, is a promising renewable fuel for heat and power generation; however, implementing crude bio-oil in some current combustion systems can degrade combustion performance and emissions. In this study, optimizing fuel properties to improve combustion is considered. Various bio-oils with different fuel properties are tested in a pilot stabilized spray burner under very close flow conditions. Effects of solids, ash and water content of bio-oil as well as ethanol blending were examined. The results show the amount of solids and ash fractions of the fuel were correlated with combustion efficiency. The CO and unburned hydrocarbon emissions decreased with both water and ethanol content. Increasing the fuel’s volatile content by blending in ethanol has been shown to improve flame stability. Also, the organic fraction of particulate matter emissions was found to be a strong function of the thermogravimetric analysis residue of the fuel.
15

Experimental Investigation of the Effects of Fuel Properties on Combustion Performance and Emissions of Biomass Fast Pyrolysis Liquid-ethanol Blends in a Swirl Burner

Moloodi, Sina 14 December 2011 (has links)
Biomass fast pyrolysis liquid, also known as bio-oil, is a promising renewable fuel for heat and power generation; however, implementing crude bio-oil in some current combustion systems can degrade combustion performance and emissions. In this study, optimizing fuel properties to improve combustion is considered. Various bio-oils with different fuel properties are tested in a pilot stabilized spray burner under very close flow conditions. Effects of solids, ash and water content of bio-oil as well as ethanol blending were examined. The results show the amount of solids and ash fractions of the fuel were correlated with combustion efficiency. The CO and unburned hydrocarbon emissions decreased with both water and ethanol content. Increasing the fuel’s volatile content by blending in ethanol has been shown to improve flame stability. Also, the organic fraction of particulate matter emissions was found to be a strong function of the thermogravimetric analysis residue of the fuel.
16

High Temperature Corrosion Of Steels Used In Petroleum Refinery Heaters

Sultan, Abdelrahman Saleh 01 July 2005 (has links) (PDF)
The oxidation of three different steels used in the construction of petroleum refineryheaters was investigated by using thermogravimetric analysis technique (TGA). C-5,P-11, and P-22 steel samples were tested in two different oxidizing environments / air and CO2+N2+H2O (that simulates the combustion products of natural gas) at two different temperatures / 450oC and 500oC. In air oxidation P-22 had the best oxidation resistance among the three steels at two temperatures. In CO2+N2+H2O environment,C-5 possessed better oxidation resistance than P-22 and P-11. Analyses of oxidation products by using optical microscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were carried out to correlate TGA results to oxide composition and morphology. Lower oxidation rate of P-22 in air was explained with reference to the formation of Cr-O phase. Analytical rate equations showed that all the steels obeyed parabolic rate equation during oxidation and no transition was observed
17

Zeólitos como dispositivo de liberação prolongada de rincoforol

Ramos, Ingrid Graça January 2012 (has links)
174 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-08-20T15:49:02Z No. of bitstreams: 1 Tese de doutorado - Ingrid - VERSÃO FINAL - UFBA.pdf: 5563445 bytes, checksum: 8345d9745885c1103c219247c69338fc (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-08-20T15:51:20Z (GMT) No. of bitstreams: 1 Tese de doutorado - Ingrid - VERSÃO FINAL - UFBA.pdf: 5563445 bytes, checksum: 8345d9745885c1103c219247c69338fc (MD5) / Made available in DSpace on 2013-08-20T15:51:20Z (GMT). No. of bitstreams: 1 Tese de doutorado - Ingrid - VERSÃO FINAL - UFBA.pdf: 5563445 bytes, checksum: 8345d9745885c1103c219247c69338fc (MD5) Previous issue date: 2012 / O rincoforol (2-metil-5(E)hepteno-4-ol) é o maior constituinte do feromônio de agregação do macho do Rhynchophorus palmarum L. (Coleoptera: Curculionidade), um besouro que ataca diversas espécies de palmeiras e é o principal vetor do nematódeo Bursaphelenchus cocophylus, agente causador da doença do anel vermelho.No Brasil, esse besouro ataca principalmente o coqueiro e o dendezeiro, culturas de grande relevância econômica para o país. Esse feromônio vem sendo utilizado em iscas do tipo eppendorf com um orifício na tampa para controlar a população do besouro. Esse dispositivo facilita a liberação lenta quando comparada à evaporação direta do estado líquido. No entanto, a validade dessas iscas depende da velocidade de evaporação do rincoforol através do dispositivo, que libera quantidade excessiva do feromônio. Com o objetivo de prolongar o tempo de liberação do rincoforol, diferentes zeólitos foram sintetizados, caracterizados e avaliados em relação à sua utilização como adsorvente para o rincoforol. Para isso, a influência de variáveis como: estrutura do zeólito, razão Si/Al, natureza do cátion de compensação, dimensão de poros e acidez foi verificada para o processo de adsorção. Devido à falta de informações referente à estabilidade do rincoforol, foi realizado um estudo termogravimétrico sobre seu comportamento térmico. Estudos de recuperação demonstraram que houve interação entre o rincoforol e os zeólitos ZSM-5 e MCM-22 nas diferentes razões Si/Al, resultando na degradação do feromônio, inviabilizando seu uso como suporte para liberação prolongada. Os materiais silicalita-1, zeólito Y e zeólito L apresentaram bons resultados de recuperação e a liberação do rincoforol a partir desses materiais foi medida em uma termobalança em condição isotérmica. Resultados promissores foram observados quando a velocidade de liberação obtida a partir dos zeólitos foi comparada com o rincoforol comercial. Assim, os estudos realizados nesse trabalho permitiu selecionar zeólitos com grande potencial comercial como dispositivo liberador do rincoforol por um período prolongado. / Salvador
18

Síntese, caracterização e estudo do comportamento térmico dos 2-metoxicinamalpiruvatos de lantanídeos (III), exceto promécio, e ítrio (III) no estado sólido

Carvalho, Cláudio Teodoro de [UNESP] 22 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-22Bitstream added on 2014-06-13T19:24:24Z : No. of bitstreams: 1 carvalho_ct_dr_araiq.pdf: 783523 bytes, checksum: 845f90e2b52f8926bba04e0f2219f870 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Sintetizou-se o ácido 2-metoxicinamalpirúvico (2-MeO-HCP), através da reação de condensação aldólica do 2-metoxicinamaldeído (CH3O-C6H4-(CH)2-CHO), 96 % de pureza com o piruvato de sódio, (Na-2-MeO-CP), 99% puro, ambos da Aldrich. A pureza do ácido 2-metoxicinamalpirúvico sintetizado foi determinada por DSC através do pico de fusão em 125 ºC. O ácido 2-metoxicinamalpirúvico foi convertido a uma solução de aproximadamente 0,15 mol L-1 de 2-metoxicinamalpiruvato de sódio (pH~7,5). Com esse sal foram sintetizados os compostos no estado sólido (Ln-2-MeO-CP.nH2O), sendo que Ln representa os lantanídeos trivalentes e Y(III), 2-MeO-CP o ligante 2-metoxicinamalpiruvato e n o número de moléculas de água com n = 1,5 para o composto de túlio e itérbio e para os demais compostos n = 1. Os Ln-2-MeO-CP.nH2O foram obtidos no estado sólido por adição lenta do ligante aos respectivos cloretos metálicos ou nitratos sob agitação contínua até a total precipitação dos íons metálicos. Os precipitados foram filtrados em papel de filtro Whatman n 42 lavando-se os mesmos com água destilada até a obtenção de teste negativo para cloretos com AgNO3 em meio nítrico e difenilamina para nitratos. Posteriormente os precipitados foram secos em temperatura ambiente e armazenados em dessecador contendo cloreto de cálcio. Técnicas instrumentais utilizadas no estudo dos compostos: Termogravimetria e Análise Térmica Diferencial Simultânea (TG-DTA) e Calorimetria Exploratória Diferencial (DSC) e Complexometria com EDTA (padrão de 1,000 x 10-2 mol L-1 ) forneceu informações sobre grau de hidratação, comportamento térmico e estequiometria; Difratometria de Raios X pelo método do pó, informações da cristalinidade e Espectroscopia de Absorção na Região do Infravermelho sugeriu a forma de coordenação dos compostos sintetizados. Na caracterização do ácido... / The 2-methoxycinnamylidenepyruvic acid (2-MeO-HCP) was synthesized through the reaction of aldolic condensation of 2-methoxycinnamaldehyde (CH3O-C6H4-(CH) 2-CHO), 96% purity, with sodium pyruvate, (Na-2 - MeO-CP) 99% pure, both from Aldrich. The purity of 2-methoxycinnamylidenepyruvic synthesized was determined by DSC through the melting peak at 125 ºC. The 2-methoxycinnamylidenepyruvic acid was converted to a solution of about 0.15 mol L-1 of the sodium 2-methoxycinnamylidenepyruvate (pH ~ 7.5). With this salt were synthesized the solid compounds (Ln-2-MeO-CP.nH2O), where Ln represents trivalent lanthanides and Y (III), 2-MeO-CP is the methoxycinnamylidenepyruvate ligand and n the number of water molecules with n = 1.5 for the compound thulium, ytterbium and for the other compounds, n = 1. The Ln-2-MeO-CP.nH2O were obtained in the solid state by slow addition of the ligand to the respective metal chlorides or nitrates on continuous stirring until total precipitation of metal ions. The precipitates were filtered through filter paper Whatman number 42, washing them with distilled water to obtain a negative test for chloride with AgNO3 in nitric acid and diphenylamine to nitrates. Subsequently the precipitates were dried at room temperature and stored in a desiccator containing calcium chloride. Instrumental techniques used in the study of compounds: Thermogravimetry and differential thermal analysis (TG-DTA), Differential Scanning Calorimetry (DSC) and Complexometry with EDTA (standard padrão de 1,000 x 10-2 mol L-1 ) provided information on degree of hydration, thermal behavior and stoichiometry; X-ray Diffractometry by the method of powder provided information about crystallinity, and Absorption Spectroscopy in the Infrared Region suggested the form of coordination of the compounds synthesized. In the characterization of 2-methoxycinnamylidenepyruvic, apart from the DSC... (Complete abstract click electronic access below)
19

Estudo t?rmico dos res?duos gerados da destila??o atmosf?rica das misturas diesel/biodiesel de dend? / Thermal study of generated waste from atmospheric distillation of diesel / biodiesel from palm oil mixtures

Aires, Jussyara Dalianne Martins 14 December 2012 (has links)
Made available in DSpace on 2014-12-17T14:08:53Z (GMT). No. of bitstreams: 1 JussyaraDMA_DISSERT_PARCIAL.pdf: 4692370 bytes, checksum: 475e965cf0951180f8df9ac44768b423 (MD5) Previous issue date: 2012-12-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The growing world demand for energy supplied by fossil fuels, a major contributor to the emission of pollutants into the atmosphere and causing environmental problems, has been encouraging governments and international organizations to reflect and encourage the use of alternative renewable sources. Among these new possibilities deserves attention biodiesel, fuel cleaner and easy to reproduce. The study of new technologies involving that source is necessary. From this context, the paper aims at analyzing the thermal stability by thermogravimetric analysis, of the waste generated from atmospheric distillation of mixtures with ratios of 5, 10, 15 and 20% palm biodiesel in diesel with and without addition of BHT antioxidant. It was synthesized biodiesel through palm oil, via homogeneous catalysis in the presence of KOH, with and without the use of BHT and subsequently added to the diesel common indoor type (S1800) from a gas station BR. The diesel was already added with 5% biodiesel, and thus the proportions used for these blends were subtracted from the existing ratio in diesel fuel, resulting in the following proportions palm oil biodiesel: 0% (B5), 5% (B10), 10 % (B15) and 15% (B20). From atmospheric distillation analysis, performed in mixtures with and without BHT were collected residue generated by each sample and performed a thermal study from the thermogravimetric analysis at a heating rate of 10 ?C.min-1, nitrogen atmosphere and heating to 600 ? C. According to the specifications of Resolution No. 7/2008 for biodiesel, it was found that the material was synthesized in accordance with the specifications. For mixtures, it was noted that the samples were in accordance with the ANP Resolution No. 42/2009. Given the TG / DTG curves of the samples of waste mixtures with and without BHT antioxidant was able to observe that they showed a single stage of thermal decomposition attributed to decomposition of heavy hydrocarbons and esters and other heavier constituents of the waste sample weighed. The thermal behavior of residues from atmospheric distillation of mixtures of diesel / biodiesel is very important to understand how this affects the proper functioning of the engine. A large amount of waste can generate a high content of particulate material, coke formation and carbonaceous deposits in engine valves, compromising their performance / A crescente demanda mundial por energia fornecida pelos combust?veis f?sseis, um dos principais respons?veis pela emiss?o de poluentes ? atmosfera e causadores de problemas ambientais, vem estimulando governos e Organismos internacionais a refletir e incentivar o uso de fontes alternativas renov?veis. Dentre essas novas possibilidades merece destaque o biodiesel, combust?vel menos poluente e de f?cil reprodutibilidade. O estudo de novas tecnologias envolvendo essa fonte faz-se necess?rio. Partindo desse contexto, o trabalho tem como objetivo principal analisar a estabilidade t?rmica, por meio da An?lise Termogravim?trica, dos res?duos gerados da destila??o atmosf?rica das misturas com propor??es de 5, 10, 15 e 20 % de biodiesel de dend? no diesel com e sem a adi??o de antioxidante BHT. Sintetizou-se o biodiesel atrav?s do ?leo de dend?, via cat?lise homog?nea na presen?a de KOH, com e sem o uso de BHT, e posteriormente, adicionou-se ao diesel comum do tipo interior (S1800) proveniente de um posto de gasolina BR. Este diesel j? estava aditivado com 5 % de biodiesel, sendo assim, as propor??es utilizadas para estas misturas foram subtra?das da propor??o existente no diesel, resultando nas seguintes propor??es de biodiesel de dend?: 0% (B5), 5% (B10), 10% (B15) e 15% (B20). Da an?lise de Destila??o Atmosf?rica, realizada nas misturas com e sem BHT, foram coletados o res?duo gerado por cada amostra e efetuado um estudo t?rmico, a partir da An?lise Termogravim?trica, na raz?o de aquecimento de 10 ?C.min-1, atmosfera de nitrog?nio e aquecimento at? 600 ?C. De acordo com as especifica??es da Resolu??o N? 7/2008 para o biodiesel, foi constatado que o material sintetizado estava em conformidade com as especifica??es. No tocante ?s misturas, notou-se que as amostras estavam de acordo com a Resolu??o da ANP N? 42/2009. Diante das curvas TG/DTG das amostras de res?duos das misturas com e sem antioxidante BHT, p?de observar que estas apresentaram uma ?nica etapa de decomposi??o t?rmica atribu?da ? decomposi??o dos hidrocarbonetos pesados e dos ?steres met?licos pesados e outros constituintes pesados da amostra de res?duo. O estudo do comportamento t?rmico do res?duo gerado da destila??o atmosf?rica das misturas de ?leo diesel/biodiesel ? de grande relev?ncia para entendermos o qu?o este interfere no bom funcionamento do motor. Uma grande quantidade de res?duos pode gerar um alto teor de material particulado, forma??o de coque e dep?sitos carbon?ceos nas v?lvulas do motor, comprometendo seu desempenho
20

Estudo da pirolise de composito de poliester insaturado com fibra de vidro em balança termogravimetrica e leito fluidizado / Kinetic study of the pyrolysis of unsatured polyester with fiberglass using thermogravimetric analysis and bubbling fluidized bed.

Silva, Giovanilton Ferreira da 22 February 2006 (has links)
Orientador: Caio Glauco Sanchez / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-10T13:46:01Z (GMT). No. of bitstreams: 1 Silva_GiovaniltonFerreirada_D.pdf: 2151460 bytes, checksum: b4f7aed8eddbf42f0d871e6e526ef9b0 (MD5) Previous issue date: 2006 / Resumo: Objetivo deste trabalho foi obter os parâmetros cinéticos do poliéster insaturado com fibra de vidro em balança termogravimétrica e a aplicação do leito fluidizado como reator de pirólise. Primeiramente foi feito um estudo para escolher o modelo cinético a partir dos dados obtidos na balança termogravimétrica. O resultado apontou o modelo de primeira ordem como o mais adequado. Foi feito um planejamento fatorial 22 a fim de avaliar a influência que as variáveis, taxa de aquecimento e diâmetro da partícula, tiveram nos parâmetros cinéticos. Os resultados do planejamento fatorial mostraram que a taxa de aquecimento foi o fator mais importante seguido do diâmetro da partícula, e não houve interação entre os fatores. A energia de ativação foi inversamente proporcional com a taxa de aquecimento e diretamente proporcional com o diâmetro da partícula. A taxa de 10°C/min foi a taxa que forneceu os melhores parâmetros cinéticos. Para leito fluidizado foi proposto um planejamento fatorial 23 para avaliar a influência das variáveis, temperatura, velocidade de fluidização e altura do leito fluidizado, tiveram no rendimento da fração liquida, gasosa e sólida. Os resultados mostraram que a temperatura foi a variável que mais influenciou o processo de pirólise em leito / Abstract: The aim of this work was to find out the kinetic parameters of unsatured polyester with fiberglass using thermogravimetric analysis, and to apply a fluidized bed like pyrolysis reactor. Firstly, it was selected a kinetic model most suitable to use with obtained data from thermogravimetric analysis. The results pointed the first order model like most suitable. It was performed a factorial analysis 22 in order to analyze the system. The experimental variables have varied simultaneously and systematically (heating rate and particle diameter). The responsevariables were used to evaluate the kinetic parameters. The experimental results of the factorial design showed that heating rate was the effect more significant and there were not interactions between the studied variables. The results showed that activity energy decreased when the heating rate increased and, it increased with increasing particle diameter. The heating rate of 10°C/min achieved the best kinetic parameters. Statistical method was applied to fluidized bed followed a 23 factorial design to evaluate the influence of variables: temperature, fluidized rate and height of fluidized bed. Response variables were yield of oil, yield of gas and, yield of solid. The results showed that temperature was the variable most significant for the pirolysis process at fluidized bed. / Doutorado / Termica e Fluidos / Doutor em Engenharia Mecânica

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