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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.
161

Valorisation de chars issus de pyrogazéification de biomasse pour la purification de syngas : lien entre propriétés physico-chimiques, procédé de fonctionnalisation et efficacité du traitement / Valorization of chars from biomass pyrogasification for syngas purification : relationship between physico-chemical properties, functionalization process and purification efficiency

Hervy, Maxime 22 November 2016 (has links)
La pyrogazéification est un procédé de conversion thermochimique prometteur pour la valorisation énergétique des biomasses et des déchets. Ce procédé conduit à la production d’un vecteur énergétique gazeux appelé « syngas » composé principalement de CO et d’H2 mais contenant également de nombreux polluants issus des déchets entrants et/ou générés au cours de la conversion. En fonction de sa pureté, le syngas peut être valorisé dans de nombreuses applications. Cependant, la formation simultanée de résidus solides (chars) sans voie de valorisation, ainsi que le coût élevé de l'étape de purification du syngas freinent le développement industriel de cette filière. Cette thèse s'intéresse à ces deux problématiques en étudiant la valorisation des chars de pyrolyse, avec ou sans adjonction de fonctions chimiques, comme adsorbants et catalyseurs pour la purification du syngas. Dans cette étude, les chars ont été produits par pyrolyse de déchets générés sur des navires de croisière et générés en quantités importantes par les sociétés modernes : Bois de Palettes Usagées, Boues de Coagulation-Floculation et Déchets Alimentaires. Une séquence de caractérisations multi-échelle a été mise en place afin de relier les caractéristiques physico-chimiques des chars aux conditions de production ainsi qu’à la nature des déchets entrants. Les chars résultants du mélange BF/DA montrent une composition chimique riche en espèces minérales tandis que les chars produits à partir de BPU sont des matériaux très majoritairement composés de carbone. L’activation à la vapeur ne modifie pas significativement la composition des chars, mais permet de développer efficacement leur porosité. L’étude s’est ensuite intéressée aux relations existant entre les propriétés physico-chimiques des chars et leur efficacité épuratoire. La capacité d’épuration d’H2S des matériaux s’est trouvée significativement améliorée par des surfaces spécifiques élevées, de hautes teneurs en espèces minérales et un pH de surface basique. Les propriétés les plus influentes pour l’activité catalytique des chars pour le craquage des goudrons (l’éthylbenzène et le benzène sont pris comme références) en gaz légers sont : la présence d’espèces minérales, la porosité et la présence de structures carbonées désordonnées dans la matrice du char. / The pyrogasification is a thermochemical process that consists in converting biomass and/or waste into a gaseous energy carrier named syngas. This syngas is mainly composed of H2 and CO but also contains many pollutants (such as tars, H2S, HCl, particles…) that must be removed before further utilization of the syngas (electricity and heat production, synthesis of biofuel or chemicals…). The production of solid residues (chars) and the cost of the syngas purification process jeopardize the industrial development of this process. This thesis aims at studying the in-situ valorisation of the pyrolysis chars, functionalized or not, as sorbent or catalyst for the syngas cleaning. In this study, pyrolysis chars have been produced by the pyrolysis of wastes generated on cruise-ships: Used Wood Pallets (UWP), Coagulation-Flocculation Sludge (CFS) and Food Waste (FW). A set of multi-scale characterizations has been performed in order to identify relationships between the physico-chemical properties of the chars, the production conditions and the nature of the initial biomass. Chars from the mixture of FW/CFS have high mineral contents while chars from UWP are mainly carbonaceous materials. The steam activation only slightly modifies the chemical composition of the chars but significantly increases their porosity. Then, the study focused on the relationships between the physico-chemical properties of the chars and their purification efficiency. The H2S sorption capacity was strongly improved by high surface areas, large mineral contents and alkaline pH surfaces. The most important properties for the catalytic activity of the chars for tar cracking reactions were: high mineral contents, large surface areas and the presence of disorganized carbon structures in the char.
162

Mogućnosti korišćenja energije pirolizom poljoprivredne biomase / The possibilities for application of energy from agricultural biomass pyrolysis

Brankov Saša 10 April 2017 (has links)
<p>U doktorskoj disertaciji realizovano je istraživanje mogućnosti konverzije energije različitih vrsta poljoprivredne biomase procesom pirolize. Ispitivanu poljoprivrednu biomasu predstavljale su p&scaron;enična, ovsena, sojina slama, slama od kukuruzovine kao i me&scaron;avina navedenih slama. Dobijeni eksperimentalni rezultati ukazuju da prinos gasa, tečne i čvrste faze tokom odvijanja procesa pirolize zavise od vi&scaron;e parametara vođenja procesa među kojima dominantan uticaj imaju reakciono vreme, temperatura i brzina<br />zagrevanja.</p> / <p>Doctoral dissertation investigates possibilities for energy conversion of different agricultural biomass types through pyrolysis process. Investigated agricultural biomass included wheat, corn, oat, soy straw and the mixture of mentioned straws. Obtained experimental results imply that gas, liquid and solid phase yields during pyrolysis process depend on various process parameters, where the reaction time, temperature and heating rate have dominant influence.</p>
163

TECHNO-ECONOMIC ANALYSIS OF WOOD PYROLYSIS IN SWEDEN

Salman, Chaudhary Awais January 2014 (has links)
The significance of bio fuels production is increasing as fossil fuels are being depleted and energy security is gaining importance in the final energy mix. Moreover, bio fuel production offers the potential to alleviate concerns regarding global warming and air pollution. The process scheme design and parameter value choices used in this analysis are exclusively based on research domain literature by considering the state of the art of pyrolysis technology. Henceforth, the results should not be interpreted as optimal performance of mature technology, but as the most likely performance given the current state of scientific knowledge. The purpose of this thesis is to study and assess the technical and economic models for the conversion of woody biomass to valuable biofuel products via fast pyrolysis. The mass rate of wood is considered as 100,000 t/y. Bio fuel production from pyrolysis is energy intensive process. Therefore, heat and energy requirement calculation for the process and optimum heat integration is necessary to improve the overall thermodynamic efficiencies for wood biomass pyrolysis. Three different cases are discussed in this thesis: 1. fast pyrolysis at 500 oC, 2. fast pyrolysis at 1000 oC   and 3. Slow pyrolysis at 500 oC.    Literature study was conducted for different pyrolysis processes and based on their findings and results a model was developed on excel for the calculation of mass and energy balance. Mass balance results shows that the process can be selected on the basis of final product required. It was found that fast pyrolysis at 500 oC is used when bio oil is the priority product, for maximizing the syngas yield fast pyrolysis at high temperature 800-1000 oC is preferred. Similarly slow pyrolysis is used for maximizing bio char yield. It was also found that raw material type and its pretreatment also has strong influence on the pyrolysis process and final composition of bio fuels. Heat flux and energy streams for the pyrolysis scheme are also designed and syngas was selected to fulfil the heat requirements for different processes alongside with pyrolysis such as drying and grinding. It was found out that syngas combustion and heat recovery from the condenser will be able to fulfill the heat demand for pyrolysis process. However the specific heat requirement for fast and slow pyrolysis process varies. According to the calculations heat flux requirement for slow pyrolysis is higher than the fast pyrolysis. An explanation for this variability of the heat for wood pyrolysis is exothermic primary char formation process competing with an endothermic volatile formation process which makes it as overall endothermic process. But pretreatment of wood or biomass in fast pyrolysis is extra burden on the total heat demand for fast pyrolysis. Economic assessment for the pyrolysis plants is also conducted through literature survey of already installed plants and it was found out that pyrolysis is more feasible for large production facilities. The trends shows that capital costs increase with the increase of plant size but the capital cost curve moves towards a straight line after reaching the certain value the production cost per gallon of bio fuel decreases with the increase of plant capacity. The cost of biofuel is extremely sensitive to variations in operating cost (for example, cost of feed stock such as wood and selling price of products) but is not significantly affected by the variations in capital cost.
164

Evolution of particle morphology during char conversion processes applied for the CFD modeling of an entrained-flow gasifier

Nguyen, Cong Bang 06 July 2021 (has links)
The change in morphology of a char particle affects both its trajectory and carbon consumption rate, hence the performance and efficiency of an entrained-flow gasifier. Among key processes taking place in the gasifier, the char conversion process is a limiting step for the overall carbon conversion. For that reason, the Ph.D. thesis presents the evolution of morphology of char particles during the carbon conversion process using particle-resolved transient CFD calculations. Analyses of numerical data obtained from the transient CFD calculations were carried out. As a result, new sub models related to the drag coefficient and the fundamental parameters of char conversion model were emerged. The new sub models were applied for modeling a pressured entrained-flow gasifier at laboratory scale. The numerical results of the gasifier show a good agreement with experimental data and an improvement of the sub models applied.
165

Influence of wood on the pyrolysis of poultry litter

Mante, Nii Ofei Daku 21 October 2008 (has links)
Pyrolytic oils produced from poultry litter differ in physico-chemical properties and the chemical composition. The litter is composed of manure and bedding material with traces of spilled feed and feathers. The type and amount of bedding material was varied to investigate its influence on the pyrolysis of layer manure. 400g of each feedstock: manure, wood (pine and oak), and mixtures of manure and wood in proportions (75:25 50:50, and 25:75 w/w %) respectively were subjected to fast pyrolysis at 450oC in a fluidized bed reactor. The total pyrolytic oil yield ranged from 43.3% to 64.5 wt%. The highest bio oil yield and the lowest char yield were obtained from oak wood. The manure oil had the highest HHV of 29.7 MJ/kg, the highest pH (5.89), the lowest density (1.14 g/cm3) and a relatively low viscosity of 130cSt. The oils had relatively high nitrogen content ranging from 5.88wt% to 1.36 wt%; low ash content (approximately <0.07wt %) and low sulfur content (<0.28wt %). FT-IR, 13CNMR, and 1HNMR analysis showed that manure oil was rich in aliphatic hydrocarbon and primary and secondary amides and the addition of wood introduced oxygenated compounds like aliphatic alcohols, phenols, aromatic ethers, and carbonyl/carboxylic groups into the oil. TG/DTG analysis also showed that the thermal decomposition of the oils were different depending on the amount and the type of wood in the manure/wood mixture. The parametric variables used for the mixture of 50% manure and 50% pine wood shavings study were; temperature (400-550°C), nitrogen gas flow rate (12-24 L/min), and feed rate (160-480 g/h). The results showed that the pyrolysis product yields, physical properties and the chemical composition of the oil were influenced by all parameters. Temperature was the most influential factor and its effect on the liquid, char and gas yields were significant. It was evident that depending on the gas flow rate and the feed rate, a maximum oil yield (51.1wt.%) can be achieved between 400-500 oC. Also an increase in temperature significantly increased the oil viscosity and decreased the carbonyl/carboxylic and the primary aliphatic alcohol functional groups in the oil. The study on the influence of wood on the stability of the oils when stored at ambient conditions for 8 months in a 30ml glass bottle showed that the viscosity of the oils increases when stored, however the manure oil was relatively more stable and the oil from the 50/50 mixture for both pine and oak was the least stable. It was found that the stability of the oils from the manure and wood mixtures were dependent on the amount and the type of wood (pine or oak) added to the manure. Also the addition of 10% solvent (methanol/ethanol) to the oil from 50% manure and 50% pine reduced the initial viscosity of the oil and was also beneficial in slowing down the increase in viscosity during storage. / Master of Science
166

Análise numérica e experimental de vigas de madeira laminada colada em situação de incêndio / Numerical and experimental analysis of glued laminated timber in fire situation

Martins, Gisele Cristina Antunes 29 July 2016 (has links)
Elementos estruturais de Madeira Laminada Colada (MLC) têm sido muito utilizados na América do Norte e na Europa. Entretanto no Brasil há restrições quanto ao uso, principalmente, em razão da insegurança diante de potenciais riscos relacionados a incêndios. Este trabalho investigou o comportamento térmico e mecânico de elementos estruturais de MLC expostos à curva de incêndio-padrão ISO 834, preparados com duas espécies de madeira (Eucalyptus e Pinus) sem adição de tratamentos preservantes. Adicionalmente, elementos tratados com preservante ignífugo a base Borato de Cobre Cromatado (MOQ® OX 50CCBO) ou tratamento retardantes ao fogo (OSMOGUARD® FR100) também foram utilizados para analisar a influência na carbonização. O objetivo principal da pesquisa foi analisar a resistência ao fogo de elementos de MLC, avaliando a influência da espécie de madeira, a influência da densidade, bem como os efeitos dos tratamentos preservantes. O programa experimental foi realizado no forno horizontal a gás instalado no Departamento de Engenhara das Estruturas - EESC/USP, com dimensões internas de 3m x 4m x 1,5m, e as análises numéricas foram implementadas no pacote computacional ABAQUS. O modelo numérico, com vistas ao monitoramento a deflexão no meio do vão e a avaliação da distribuição da temperatura ao longo da profundidade dos elementos, foram desenvolvidos e os resultados obtidos foram comparados com os dados obtidos por meio das análises experimentais. Métodos de cálculo propostos por diferentes autores e regulamentações internacionais foram aplicados para verificação das propostas de dimensionamento em situação de incêndio. A comparação dos resultados mostrou que a utilização dos métodos de dimensionamento (simplificado ou avançado) representa risco à segurança contra incêndio caso utilize valores para a taxa de carbonização das espécies nacionais determinados a partir dos métodos de cálculo ou normas internacionais. / Structural elements of Glued Laminated Timber (glulam) have long been used in North America and Europe, but their use is still restricted in Brazil for safety reasons, especially related to potential risks in face of fire. The present work investigated the thermal and mechanical behavior of structural elements of glulam exposed to fire standard ISO 834. The glued laminated timber was produced from two wood species (Eucalyptus and Pinus) without any treatments. However, elements treated with wood treatments like Copper Chrome Boron (MOQ® OX 50 -CCB-O) or fire retardant treatment (OSMOGUARD® FR100) were also used to investigate their influence on charring. The main objective of this study was to assess the fire resistance of the glulam elements, evaluating the influence of wood species and, consequently, the influence of density, as well as the effects of preservative treatment. The experimental program was carried out in a gas oven, with internal dimensions of 3m x 4m x 1.5m, and the numerical analyses were performed by ABAQUS. The numerical analyses aimed to monitor the deflection in the middle of the span as well as the temperature distribution along the depth of the elements. The results obtained from both the experimental and numerical analyses were compared. Calculation methods proposed by different authors and international regulations have been applied for verification of the proposed design in fire. A comparison of the results show that the use of calculation methods (simplified and advanced) represents a risk to fire safety in case of using the values of char rate for Brazilian wood species determined from the calculation methods.
167

Re-examining Ceratomyxa shasta in the Pacific Northwest

Stinson, Matthew Everett Tsuneo, 1982- 17 February 2012 (has links)
Ceratomyxa shasta infects salmonids in the Pacific Northwest (PNW) of North America, occasionally causing losses in wild and captive populations. Host-specific parasite genotypes (O, I, II, III) were previously characterized molecularly using markers in the ribosomal DNA and phenotypically by type host in the Klamath River, CA/OR. This thesis sough to re-examine the composition of the parasite population elsewhere in the PNW and to further evaluate the host specificity of each genotype. I surveyed salmonids native to the PNW primarily from the Fraser, the Columbia and the Sacramento River basins. I also conducted sentinel studies on the Willamette and Deschutes Rivers that exposed native and non-native salmonids to parasite populations above and below migration barriers. These studies expanded upon the known host range of each genotype: O was specific to rainbow/steelhead (Oncorhynchus mykiss) and coastal cutthroat trout (O. clarkii); I was specific with Chinook salmon (O. tshawytscha); II was non-specific, being detected in six species, but predominating in coho (O. kitsuch), chum (O. keta), and pink (O. gorbuscha) salmon; and III was also non-specific infecting many native and non-native salmonids. Hosts infected with genotype III were considered “adequate” if myxospore development occurred, and included brook char (Salvelinus fontinalis), brown (Salmo trutta), rainbow, cutthroat, and steelhead trout; but Chinook, kokanee/sockeye (O. nerka) and Atlantic salmon (Salmon salar) were less suitable. The distribution, life history, and phylogenetic traits of each salmonid host are factors that potentially explain the host specificity and the spatial and temporal patterns of each genotype. Data collected in this thesis provide evidence that host-specific C. shasta coevolved with Pacific salmonids, adapting unique host-parasite relationships over time. / Graduation date: 2012
168

Le langage théologique du Mal et du Salut dans la trilogie de Hans Urs von Balthasar. Une base pour la réflexion sur le langage de la théologie

Planchon, Félicien 08 April 2003 (has links)
Le mystère du mal – faute et/ou malheur – est la limite la plus compacte à laquelle se heurte la réflexion humaine en général et la réflexion théologique en particulier. J'ai entrepris de lire sous cet angle la trilogie de Balthasar, qui est son œuvre centrale : il s'agit de voir comment un théologien contemporain du calibre de Balthasar affronte ce mystère, et en quels termes se présentent pour lui le désir humain et l'espoir chrétien de salut. L'approche de Balthasar est phénoménologique ; mais à ce propos deux précisions s'imposent. D'une part, cette phénoménologie est théologique : l'événement de Révélation est sans analogie ; on ne peut le ranger parmi les autres phénomènes. D'autre part, une telle phénoménologie se situe au pôle positif d'un « choix fondamental ». Ce choix, qui est un leitmotiv qu'on peut suivre à la trace dans toute la trilogie, décide de l'orientation de toute vie spirituelle : ou bien l'être humain, en présence de ce qui s'offre à sa conscience connaissante, tend à se développer, s'affirmer, s'approfondir, ou bien au contraire, il se laisse saisir et emporter par le mystère de ce qu'il lui est donné de percevoir. La réflexion théologique de Balthasar a comme axe principal la kénose divine : kénose intra-trinitaire (le dépouillement mutuel des personnes divines l'une envers l'autre) ; kénose de création (Dieu posant hors de lui des créatures capables de s'opposer à lui) ; kénose d'alliance (Dieu s'impliquant dans les aléas d'une alliance avec son peuple) ; kénose révélatrice (l'Incarnation, la Passion et la mort en Croix du Verbe divin). Le thème récurrent est celui de la « non-puissance » de Dieu, de la « non-figure » du Fils ensanglanté et mourant sur la Croix. La kénose du Fils incarné s'inscrit dans une logique visionnaire, répondant à un souci obsessif de Balthasar : le souci du « salut-pour-tous ». En effet, le Fils incarné subit l'abandon du Père, jusqu'à partager l'enfermement sans issue des réprouvés éventuels: la « Descente aux Enfers », c'est l'épreuve de la « non-puissance » extrême, seule capable de délivrer l'éventuel réprouvé sans faire violence au Libre Arbitre qui, selon la doctrine, définit la dignité de la personne humaine. La théologie négative, selon Balthasar, n'est pas l'arrêt de la raison humaine devant l'infini divin qui dépasse les limites de la conscience connaissante : pour Balthasar, c'est la contemplation du mystère inconcevable de la kénose divine, de l'inimaginable dépouillement divin dans la Passion du Fils et la Descente aux Enfers. La kénose du Fils incarné, ce n'est pas un acte distinct du Dieu tout-puissant, qui se séparerait de sa toute-puissance pour rejoindre le niveau de la condition humaine : le dépouillement, la non-puissance, c'est la définition même de Dieu dans la vie trinitaire. Selon Balthasar, la Passion, la mort, l'abandon du Christ jusque dans les ténèbres de la perdition révèlent Dieu tel qu'il est de toute éternité. Percevoir le divin dans la « non-figure » du Christ en croix, c'est recevoir le don du regard simple, c'est se tenir au pôle positif du « choix fondamental » : être emporté, ravi par le mystère qui se révèle. Ainsi se définit ce que Balthasar rappelle avec insistance : l'humilité de la théologie et de son langage: l'ouverture contemplative au mystère et le respect des failles de toute construction « théo-logique », failles par lesquelles se manifeste le mystère de l'indicible, qui bouscule nos habitudes et nos représentations.
169

Estudo da influ?ncia da temperatura na degrada??o termoqu?mica da biomassa de avel?s

Avelar, Karen Pereira Batista de 18 October 2013 (has links)
Made available in DSpace on 2014-12-17T15:01:32Z (GMT). No. of bitstreams: 1 KarenPBA_DISSERT.pdf: 3887883 bytes, checksum: 3ebc4a634530a0a4a6493a962284d14f (MD5) Previous issue date: 2013-10-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The bio-oil obtained from the pyrolysis of biomass has appeared as inter-esting alternative to replace fossil fuels. The aim of this work is to evaluate the influence of temperature on the yield of products originating from the pyrolysis process of the powder obtained from the dried twigs of avel?s (Euphorbia tirucalli), using a rotating cylinder reactor in laboratory scale. The biomass was treated and characterized by: CHNS, moisture, volatiles, fixed carbon and ashes, as well as evaluation of lignin, cellulose and hemicellulose, besides other instrumental techniques such as: FTIR, TG/DTG, DRX, FRX and MEV. The activation energy was evaluated in non-isothemichal mode with heating rates of 5 and 10 oC/min. The obtained results showed biomass as feedstock with potential for biofuel production, because presents a high organic matter content (78,3%) and fixed-carbon (7,11%). The activation energy required for the degradation of biomass ranged between 232,92 392,84 kJ/mol, in the temperature range studied and heating rate of 5 and 10?C/min. In the pyrolysis process, the influence of the reaction temperature was studied (350-520 ? C), keeping constant the other variables, such as, the flow rate of carrier gas, the centrifugal speed for the bio-oil condensationa, the biomass flow and the rotation of the reactor. The maximum yield of bio-oil was obtained in the temperature of 450?C. In this temperature, the results achieved where: content of bio-oil 8,12%; char 32,7%; non-condensed gas 35,4%; losts 23,8%; gross calorific value 3,43MJ/kg; pH 4,93 and viscosity 1,5cP. The chromatographic analysis of the bio-oil produced under these conditions shows mainly the presence of phenol (17,71%), methylciclopentenone (10,56%) and dimethylciclopentenone (7,76%) / O bio-?leo obtido da pir?lise da biomassa tem aparecido como alternativa interessante para substitui??o dos combust?veis f?sseis. O objetivo deste trabalho ? avaliar a influ?ncia da temperatura no rendimento dos produtos originados do processo de pir?lise do p? obtido dos galhos secos do avel?s (Euphorbia tirucalli), utilizando um reator de cilindro rotativo em escala de laborat?rio. A biomassa foi tratada e caracterizada por: CHNS, umidade, materiais vol?teis, cinzas e carbono fixo, bem como, avalia??o dos teores de lignina, celulose e hemicelulose, al?m de outras t?cnicas instrumentais, tais como: FTIR, TG/DTG, DRX, FRX e MEV. A energia de ativa??o foi avaliada no regime n?o isot?rmico com taxas de aquecimento de 5 e 10 oC/min. Os resultados obtidos mostraram a biomassa como mat?ria prima com potencial para produ??o de biocombust?veis, pois apresenta alto teor de mat?ria org?nica (78,3%) e carbono fixo (7,11%). A energia de ativa??o exigida para degrada??o da biomassa variou entre 232,92 392,84 kJ/mol, no intervalo de temperatura da rea??o estudado e taxa de aquecimento de 5 e 10oC/min. No processo de pir?lise, estudou-se a influ?ncia da temperatura da rea??o (350-520 ?C), mantendo-se constantes as demais vari?veis, ou seja, a vaz?o do g?s de arraste , a velocidade de centrifuga??o para condensa??o do bio-?leo, a vaz?o de biomassa e a rota??o do reator. O rendimento m?ximo em bio-?leo foi obtido na temperatura de 450?C. Nessa temperatura, os resultados alcan?ados foram: teor de bio?leo de 8,12%; carv?o 32,7%; fase gasosa n?o condensada 35,4%; perdas 23,8%; poder calor?fico superior 3,43MJ/kg; pH 4,93; viscosidade 1,5cP. A an?lise cromatogr?fica do bio-?leo produzido nessas condi??es mostra a presen?a, principalmente, de fenol (17,71%), metilciclopentenona (10,56%) e dimetilciclopentenona (7,76%)
170

Estudo da influ?ncia da temperatura na degrada??o termoqu?mica da biomassa de avel?s (euphorbia tirucalli Linn) / Study of the influence of the temperature in the thermochemical degradation of the biomass of avel?s (euphorbia tirucalli Linn)

Avelar, Karen Pereira Batista de 18 October 2013 (has links)
Made available in DSpace on 2014-12-17T15:01:35Z (GMT). No. of bitstreams: 1 KarenPBA_DISSERT.pdf: 3887883 bytes, checksum: 3ebc4a634530a0a4a6493a962284d14f (MD5) Previous issue date: 2013-10-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The bio-oil obtained from the pyrolysis of biomass has appeared as inter-esting alternative to replace fossil fuels. The aim of this work is to evaluate the influence of temperature on the yield of products originating from the pyrolysis process of the powder obtained from the dried twigs of avel?s (Euphorbia tirucalli), using a rotating cylinder reactor in laboratory scale. The biomass was treated and characterized by: CHNS, moisture, volatiles, fixed carbon and ashes, as well as evaluation of lignin, cellulose and hemicellulose, besides other instrumental techniques such as: FTIR, TG/DTG, DRX, FRX and MEV. The activation energy was evaluated in non-isothemichal mode with heating rates of 5 and 10 oC/min. The obtained results showed biomass as feedstock with potential for biofuel production, because presents a high organic matter content (78,3%) and fixed-carbon (7,11%). The activation energy required for the degradation of biomass ranged between 232,92 392,84 kJ/mol, in the temperature range studied and heating rate of 5 and 10?C/min. In the pyrolysis process, the influence of the reaction temperature was studied (350-520 ? C), keeping constant the other variables, such as, the flow rate of carrier gas, the centrifugal speed for the bio-oil condensationa, the biomass flow and the rotation of the reactor. The maximum yield of bio-oil was obtained in the temperature of 450?C. In this temperature, the results achieved where: content of bio-oil 8,12%; char 32,7%; non-condensed gas 35,4%; losts 23,8%; gross calorific value 3,43MJ/kg; pH 4,93 and viscosity 1,5cP. The chromatographic analysis of the bio-oil produced under these conditions shows mainly the presence of phenol (17,71%), methylciclopentenone (10,56%) and dimethylciclopentenone (7,76%) / O bio-?leo obtido da pir?lise da biomassa tem aparecido como alternativa interessante para substitui??o dos combust?veis f?sseis. O objetivo deste trabalho ? avaliar a influ?ncia da temperatura no rendimento dos produtos originados do processo de pir?lise do p? obtido dos galhos secos do avel?s (Euphorbia tirucalli), utilizando um reator de cilindro rotativo em escala de laborat?rio. A biomassa foi tratada e caracterizada por: CHNS, umidade, materiais vol?teis, cinzas e carbono fixo, bem como, avalia??o dos teores de lignina, celulose e hemicelulose, al?m de outras t?cnicas instrumentais, tais como: FTIR, TG/DTG, DRX, FRX e MEV. A energia de ativa??o foi avaliada no regime n?o isot?rmico com taxas de aquecimento de 5 e 10 oC/min. Os resultados obtidos mostraram a biomassa como mat?ria prima com potencial para produ??o de biocombust?veis, pois apresenta alto teor de mat?ria org?nica (78,3%) e carbono fixo (7,11%). A energia de ativa??o exigida para degrada??o da biomassa variou entre 232,92 392,84 kJ/mol, no intervalo de temperatura da rea??o estudado e taxa de aquecimento de 5 e 10oC/min. No processo de pir?lise, estudou-se a influ?ncia da temperatura da rea??o (350-520 ?C), mantendo-se constantes as demais vari?veis, ou seja, a vaz?o do g?s de arraste , a velocidade de centrifuga??o para condensa??o do bio-?leo, a vaz?o de biomassa e a rota??o do reator. O rendimento m?ximo em bio-?leo foi obtido na temperatura de 450?C. Nessa temperatura, os resultados alcan?ados foram: teor de bio?leo de 8,12%; carv?o 32,7%; fase gasosa n?o condensada 35,4%; perdas 23,8%; poder calor?fico superior 3,43MJ/kg; pH 4,93; viscosidade 1,5cP. A an?lise cromatogr?fica do bio-?leo produzido nessas condi??es mostra a presen?a, principalmente, de fenol (17,71%), metilciclopentenona (10,56%) e dimetilciclopentenona (7,76%)

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