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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.
101

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
102

Hydrodésoxygénation de composés phénoliques modèles. Évaluation de phases actives : sulfures, oxyde, métallique et phosphure / Hydrodeoxygenation of model phenolic compounds. Evaluation of active phases : sulfide, oxide, metallic and phosphide

Gonçalves, Vinicius Ottonio Oliveira 24 May 2017 (has links)
Dans une bioraffinerie, la biomasse peut être transformée par différents procédés (thermiques, chimiques et biochimiques) en carburants et en produits chimiques à haute valeur ajoutée. Plus spécifiquement, le procédé catalytique d'hydrodésoxygénation (HDO) devrait permettre de valoriser à la fois les bio-huiles obtenues par pyrolyse en biocarburants, ainsi que les composés aromatiques oxygénés issus de la dépolymérisation de la lignine en aromatiques simples.Afin de modéliser la désoxygénation de ces fractions, les isomères du crésol (ortho-, méta- et para-crésol) ont été choisis comme molécules oxygénés modèles. Les réactions ont été effectuées sous haute pression (2-4 MPa) et à des températures comprises entre 250 et 340° C. Plusieurs phases actives à base de molybdène (sulfures et oxyde) et de nickel (métallique et phosphure) ont été étudiées. L'influence du support des phases oxydes de molybdène (SiO2, SBA-15, Al2O3) et des phases à base de nickel (SiO2 et ZrO2) a également été examinée.Dans ces conditions expérimentales, les composés phénoliques sont désoxygénés selon deux voies de transformations parallèles. La voie de désoxygénation directe (DDO) conduit uniquement au toluène par hydrogénolyse de la liaison C-O. La voie hydrogénante (HYD), quant à elle, conduit à un mélange de produits obtenus après hydrogénation du cycle aromatique, impliquant des réactions d'hydrogénolyse, d'hydrogénation, de déshydratation et d'isomérisation. L'activité des catalyseurs ainsi que la contribution de chaque voie de désoxygénation sont dépendantes de la phase active étudiée, du support choisi ainsi que des conditions opératoires utilisées. / In a biorefinery, biomass can be converted by different process (thermal, chemical and biochemical) into fuels and valued-added chemicals. More specifically, the catalytic hydrodeoxygenation (HDO) process could upgrade both bio-oils obtained from pyrolysis into biofuels and oxygenated aromatic compounds from the depolymerization of lignin into aromatics.In order to model the deoxygenation of these fractions, the cresol isomers (ortho, meta and para-cresol) were chosen as model oxygenated molecules. The reactions were carried out under high pressure (2-4 MPa) and temperatures between 250 and 340° C. Several active phases based on molybdenum (sulphides and oxide) and nickel (metal and phosphide) have been studied. The influence of the support of the molybdenum oxide phases (SiO2, SBA-15, Al2O3) and of the nickel-based phases (SiO2 and ZrO2) was also examined.Under these experimental conditions, phenolic compounds are deoxygenated by two parallel pathways. The direct deoxygenation (DDO) route only leads to toluene by hydrogenolysis of the C-O bond. The hydrogenating route (HYD), on the other hand, leads to a mixture of products obtained through the hydrogenation of cresol aromatic ring, involving hydrogenolysis, hydrogenation, dehydration and isomerization reactions. The activity of the catalysts as well as the contribution of each deoxygenation pathway are dependent on the active phase studied, on the support chosen as well as on the operating conditions used.
103

Medição experimental e previsão de velocidade do som de componentes de biocombustíveis / Measureament and predict of speed of sound of biofuel compounds

Deivisson Lopes Cunha 15 March 2013 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / A velocidade do som é uma propriedade que vem sendo cada vez mais utilizada em diferentes áreas tecnológicas. Além disso, a velocidade do som é uma propriedade termodinâmica que está associada a outras propriedades do meio como a compressibilidade isentrópica e isotérmica, entre outras. Neste contexto, muitos estudos foram realizados a fim de obter modelos precisos que possam representar fielmente a velocidade do som, sendo observados desvios absolutos médios entre 0,13 e 24,8%. Neste trabalho, um banco de dados de velocidade do som e massa específica à pressão atmosférica de n-alcanos, alcanos ramificados, n-alcenos, aromáticos, alcoóis, éteres e ésteres, foram compilados da literatura aberta. Utilizando estes dados e baseando-se no modelo de Wada por contribuição de grupo recentemente proposto, foi desenvolvido um novo modelo por contribuição atômica para predizer a velocidade do som de todas as famílias dos compostos investigados neste trabalho. É mostrado que o modelo proposto é capaz de prever a velocidade do som para os compostos destas famílias com desvios próximos da incerteza experimental calculada a partir de diferentes dados da literatura. Este trabalho também discute o efeito da ramificação das cadeias na constante Wada, ressaltando a importância de novas medições para este tipo de compostos. Além disso, observou-se que a literatura necessita de mais dados experimentais de velocidade do som, à pressão atmosférica e diferentes temperaturas para substâncias puras presentes em biodiesel e bio-óleo de pirólise rápida. Neste contexto, o presente trabalho fornece novos dados experimentais de velocidade do som e massa específica de cinco ésteres metílicos de ácidos graxos, também conhecidos como FAMEs, (caprilato de metila, caprato de metila, palmitato de metila, estearato de metila e linoleato de metila), e sete componentes puros presentes em bio-óleo de pirólise à pressão atmosférica, de vários fenóis (fenol, o-, m- e p-cresol), dois éteres fenólicos (2-metoxifenol e eugenol) e um éster fenólico (salicilato de metila), a temperaturas de (288,15-343,15) K. O modelo preditivo de Wada atômico foi utilizado para calcular a velocidade do som dos FAMEs estudados neste trabalho, e os desvios foram comparados com o modelo de Wada por contribuição de grupo. O modelo atômico de Wada foi utilizado para prever a velocidade do som dos componentes puros presentes no bio-óleo de pirólise rápida experimentalmente estudados nesta dissertação. Além disso, os dados de massa específica e velocidade de som foram correlacionados com o modelo de Prigogine-Flory-Patterson (PFP). As propriedades foram bem representadas pelo modelo PFP, no entanto, para a velocidade do som o modelo apresenta desvios sistemáticos na dependência com a temperatura. O desempenho do modelo preditivo de Wada atômico foi considerado satisfatório, devido os desvios observados serem compatíveis ou até menores do que os desvios típicos obtidos na literatura com outros modelos correlativos para o cálculo da velocidade do som de outras substâncias / Speed of sound is a property that is being increasingly used in different technological areas. Furthermore, the speed of sound is a thermodynamic property which is associated with other properties of the medium, such as isentropic and isothermal compressibility, among others. In this context, many studies were carried out to obtain accurate models that can faithfully represent the speed of sound, with average absolute deviations between 0.13 and 24.8%. In this work a database of speed of sound and density at atmospheric pressure for n-alkanes, branched alkanes, n-alkenes, aromatics, alcohols, ethers and esters were collected from the open literature. Using these data a Wada group contribution model recently proposed was used as basis for the development of a new atomic contribution model to predict speed of sound for all families of compounds investigated in this work. It is shown that the proposed model is able to predict the speed of sound for compounds of these families with deviations close to the experimental reproducibility. This work also discusses the effect of branching on the Wadas constant, pointing out the importance of new measurements for this type of compounds. It was also observed that the literature needs more experimental data of speed of sound at atmospheric pressure and different temperature for pure compounds present in biodiesel and fast pyrolysis bio-oil. In this context, this work provides new experimental data of speed of sound and density for five Fatty Acid Methyl Esters, also know FAMEs, (Methyl Caprylate, Methyl Caprate, Methyl Palmitate, Methyl Stearate and Methyl Linoleate), and seven pure components of pyrolysis bio-oil at atmospheric pressure for several phenols (phenol, o-, m- and p-cresol), two phenolic ethers (2-methoxyphenol and eugenol) and one phenolic ester (methyl salicylate) at temperatures ranging from (288.15 to 343.15) K. The predictive atomic Wada model was used to calculate speed of sound of FAMEs studied in this work, and the deviations were compared with group contribution Wada model. An extension of atomic Wada model was used to predict the speed of sound of pure compounds of fast pyrolysis bio-oil experimentally studied in this thesis. Furthermore, data of densities and speed of sound are correlated with the Prigogine-Flory-Patterson (PFP) model. The properties are well described by the PFP model, however the model presents a systematical deviation on the temperature dependency of the speed of sound. The performance of the predictive atomic Wada model was very satisfactory because its deviations are comparable to, or better than, those obtained in the literature with other models
104

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%)
105

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%)
106

Medição experimental e previsão de velocidade do som de componentes de biocombustíveis / Measureament and predict of speed of sound of biofuel compounds

Deivisson Lopes Cunha 15 March 2013 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / A velocidade do som é uma propriedade que vem sendo cada vez mais utilizada em diferentes áreas tecnológicas. Além disso, a velocidade do som é uma propriedade termodinâmica que está associada a outras propriedades do meio como a compressibilidade isentrópica e isotérmica, entre outras. Neste contexto, muitos estudos foram realizados a fim de obter modelos precisos que possam representar fielmente a velocidade do som, sendo observados desvios absolutos médios entre 0,13 e 24,8%. Neste trabalho, um banco de dados de velocidade do som e massa específica à pressão atmosférica de n-alcanos, alcanos ramificados, n-alcenos, aromáticos, alcoóis, éteres e ésteres, foram compilados da literatura aberta. Utilizando estes dados e baseando-se no modelo de Wada por contribuição de grupo recentemente proposto, foi desenvolvido um novo modelo por contribuição atômica para predizer a velocidade do som de todas as famílias dos compostos investigados neste trabalho. É mostrado que o modelo proposto é capaz de prever a velocidade do som para os compostos destas famílias com desvios próximos da incerteza experimental calculada a partir de diferentes dados da literatura. Este trabalho também discute o efeito da ramificação das cadeias na constante Wada, ressaltando a importância de novas medições para este tipo de compostos. Além disso, observou-se que a literatura necessita de mais dados experimentais de velocidade do som, à pressão atmosférica e diferentes temperaturas para substâncias puras presentes em biodiesel e bio-óleo de pirólise rápida. Neste contexto, o presente trabalho fornece novos dados experimentais de velocidade do som e massa específica de cinco ésteres metílicos de ácidos graxos, também conhecidos como FAMEs, (caprilato de metila, caprato de metila, palmitato de metila, estearato de metila e linoleato de metila), e sete componentes puros presentes em bio-óleo de pirólise à pressão atmosférica, de vários fenóis (fenol, o-, m- e p-cresol), dois éteres fenólicos (2-metoxifenol e eugenol) e um éster fenólico (salicilato de metila), a temperaturas de (288,15-343,15) K. O modelo preditivo de Wada atômico foi utilizado para calcular a velocidade do som dos FAMEs estudados neste trabalho, e os desvios foram comparados com o modelo de Wada por contribuição de grupo. O modelo atômico de Wada foi utilizado para prever a velocidade do som dos componentes puros presentes no bio-óleo de pirólise rápida experimentalmente estudados nesta dissertação. Além disso, os dados de massa específica e velocidade de som foram correlacionados com o modelo de Prigogine-Flory-Patterson (PFP). As propriedades foram bem representadas pelo modelo PFP, no entanto, para a velocidade do som o modelo apresenta desvios sistemáticos na dependência com a temperatura. O desempenho do modelo preditivo de Wada atômico foi considerado satisfatório, devido os desvios observados serem compatíveis ou até menores do que os desvios típicos obtidos na literatura com outros modelos correlativos para o cálculo da velocidade do som de outras substâncias / Speed of sound is a property that is being increasingly used in different technological areas. Furthermore, the speed of sound is a thermodynamic property which is associated with other properties of the medium, such as isentropic and isothermal compressibility, among others. In this context, many studies were carried out to obtain accurate models that can faithfully represent the speed of sound, with average absolute deviations between 0.13 and 24.8%. In this work a database of speed of sound and density at atmospheric pressure for n-alkanes, branched alkanes, n-alkenes, aromatics, alcohols, ethers and esters were collected from the open literature. Using these data a Wada group contribution model recently proposed was used as basis for the development of a new atomic contribution model to predict speed of sound for all families of compounds investigated in this work. It is shown that the proposed model is able to predict the speed of sound for compounds of these families with deviations close to the experimental reproducibility. This work also discusses the effect of branching on the Wadas constant, pointing out the importance of new measurements for this type of compounds. It was also observed that the literature needs more experimental data of speed of sound at atmospheric pressure and different temperature for pure compounds present in biodiesel and fast pyrolysis bio-oil. In this context, this work provides new experimental data of speed of sound and density for five Fatty Acid Methyl Esters, also know FAMEs, (Methyl Caprylate, Methyl Caprate, Methyl Palmitate, Methyl Stearate and Methyl Linoleate), and seven pure components of pyrolysis bio-oil at atmospheric pressure for several phenols (phenol, o-, m- and p-cresol), two phenolic ethers (2-methoxyphenol and eugenol) and one phenolic ester (methyl salicylate) at temperatures ranging from (288.15 to 343.15) K. The predictive atomic Wada model was used to calculate speed of sound of FAMEs studied in this work, and the deviations were compared with group contribution Wada model. An extension of atomic Wada model was used to predict the speed of sound of pure compounds of fast pyrolysis bio-oil experimentally studied in this thesis. Furthermore, data of densities and speed of sound are correlated with the Prigogine-Flory-Patterson (PFP) model. The properties are well described by the PFP model, however the model presents a systematical deviation on the temperature dependency of the speed of sound. The performance of the predictive atomic Wada model was very satisfactory because its deviations are comparable to, or better than, those obtained in the literature with other models
107

Aplicação de micropirólise/catalítica no estudo da conversão térmica de plantas aquáticas para a obtenção de biocombustível de 2ª geração

Lima, Lidiane Correia dos Santos 04 July 2014 (has links)
The search for alternatives to the fossil oil and concern about environmental pollution has increasingly supported the importance of biofuels. The production of bio-oil from aquatic plants (water hyacinth) has become as interesting alternative due to its rapid growth rate, robust nature and unrelated to the food chain. The present work aimed to study the application of conventional and catalytic pyrolysis to convert aquatic plants like Eichhornia crassipes (EC) and Eichhornia azurea (EA) in bio-oil, employing Ferrierite and Y zeolite as catalysts. These plants were obtained in Aracaju-SE and Itabaiana-SE, respectively. The micropyrolys is were performed at three temperatures (400, 500 and 600 °C). The catalytic micropyrolysis using Ferrierite and Y zeolite was performed in the same condition applying 1 and 5% of catalysts w/w. The bio-oils solutions obtained were characterized by GC/MS and GC-FID. The micropyrolysis performed in the absence of catalyst showed similar chromatographic profiles to the biomasses tested, with the composition of bio-oils showing phenolic compounds, acids and alcohols. With Ferrierite as catalyst at 5% in the micropyrolysis and performing a study from the total area of the obtained chromatograms was observed the higher yield by GC-FID caused by the increased formation of small molecular mass compounds from biomasses. However, when used 1% of the same catalyst to EC was not observed a very significant difference in relation with no catalyst pyrolysis. To the EA in this condition was observed a significant yield reduction when performed at 500 °C. When used Y catalyst for EA pyrolysis a smaller yield was observed at all studied temperatures that shows a significantly inhibited formation of compounds derived from these lignocelullosic biomasses. However for the EC catalytic pyrolysis with 5% of Y catalyst at 500 °C we observed the largest decrease in the yield from the chromatograms area. The bio-oils characterization gave compounds identified belong to the following classes: alcohol, phenol, and sugar acids. The bio-oils from catalytic pyrolysis of EC and EA biomass showed a high content of phenolic compounds and acidic compounds. / A procura por soluções alternativas para a substituição total ou parcial do petróleo e a preocupação com a poluição ambiental tem reforçado cada vez mais a importância da produção de biocombustíveis. Neste sentido a produção de bio-óleo a partir de plantas aquáticas tornou-se uma alternativa interessante. Estas plantas são invasoras e possuem alta taxa de crescimento, natureza robusta e não tem relação com a cadeia alimentar. Neste trabalho, biomassas provenientes de plantas aquáticas, obtidas em Itabaiana-SE e Aracaju-SE, das espécies crassipes (EC) e azurea (EA), ambas do gênero Eichhornia, foram submetidas a micropirólise convencional a três temperaturas, 400, 500 e 600 ºC, e catalítica empregando catalisadores do tipo zeólita Ferrierita e Y nas proporções de 1 e 5%. As soluções de bio-óleos produzidas foram caracterizadas por CG/EM e CG-FID. Na micropirólise realizada na ausência de catalisador foi observado semelhança na composição química do bio-óleo para todas as condições testadas. Empregando 5% de catalisador Ferrierita na micropirólise, e realizando um estudo da área total dos cromatogramas obtidos foram observados aumentos significativos a 400 ºC para EC (+53,74%) e para a EA (+43,67%). A 1% deste mesmo catalisador para a EC houve diminuição da área total nas três temperaturas, enquanto que para EA houve diminuição na área total a 500 ºC (-48,09%). Quando empregado a zeólita Y nas duas proporções foi observado menor capacidade de produção de bio-óleo para EA em todas as temperaturas estudadas. A maior diminuição de área foi a 600 ºC (-25,70%) a 1% de catalisador e quando utilizado 5% foi a 500 ºC (-84,34%), ou seja, houve a inibição significativa na formação de bio-óleo. Para a EC foi observado a maior diminuição da capacidade de conversão térmica catalítica desta biomassa em bio-óleo na condição de 5% de zeólita Y, a 500 ºC (-33,23%) e na condição de 1% de zeólita Y, a 600 ºC (-46,77%). Os principais compostos identificados nos bio-óleos obtidos foram das classes do álcoois, fenóis, ácidos e açúcares. O bio-óleo obtido por pirólise catalítica das biomassas EC e EA apresentou um alto teor de compostos fenólicos e ácidos.
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Estudo em microescala da conversão térmica e catalítica da borra do óleo de algodão para obtenção de bioquerosene

Souza, Tarciane Greyci dos Santos 13 July 2015 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study aimed to apply the micropirólise and catalytic and non-catalytic microhidropirólise, in assessing the production of bio-kerosene from the cotton oil sludge. Samples of cotton oil sludge were provided by the Northeast Center for Strategic Technologies - CETENE (experimental Plant Caetés-PE) and makes up a major waste of the productive chain of biodiesel plant. The pyrolysis was performed using 50 mg of biomass. In hidropirólises and pyrolysis temperatures were used 500 ° C and 550 also being investigated the influence of dispersion of the catalyst in the sample. The catalysts PMZ, PWZ, MT and WT tested at 10% (m/m) in the study, were produced based on the application for the petrochemical industry and are as novel for this type of application. The obtained solutions were analyzed by GC-FID and GC / MS, and the gases produced were analyzed and quantified micro-GC. The use of hydrogen gas did not minimize the production of alkenes in pyrolysis. The presence of water in the biomass optimized thermal cracking process. This cracking when performed in the presence of catalysts at 550 °C showed a higher yield of liquid biofuel to hydrocarbons in the C9 to C16 range (approximately 37%) compared to the non-catalytic treatment. The semi-quantitative analysis of gases produced in the pyrolysis suggested routes decarboxylation (in the presence of CO2) and decarbonylation (the CO present) during the catalytic thermal cracking, and demonstrate the occurrence of the Fischer-Tropsch process produces hydrocarbons in the range kerosene. / O presente trabalho teve como objetivo aplicar a micropirólise e microhidropirólise catalítica e não catalítica, na avaliação da produção de bioquerosene a partir da borra de óleo de algodão. As amostras da borra de óleo de algodão foram cedidas pelo Centro de Tecnologias Estratégicas do Nordeste CETENE (Usina experimental de Caetés-PE) e compõe um dos principais resíduos da cadeia produtiva de biodiesel da usina. As pirólises foram realizadas utilizando 50 mg de biomassa. Nas pirólises e hidropirólises foram utilizadas as temperaturas de 500 e 550 °C sendo investigado também a influência da dispersão do catalisador na amostra. Os catalisadores PMZ, PWZ, MT e WT testados a 10% (m/m) neste trabalho, foram produzidos para a aplicação na indústria petroquímica com o intuito de promover a isomerização de n-parafinas lineares que estão presentes no petróleo, aos seus respectivos isômeros ramificados, tendo como produto final uma gasolina com alto índice de octanagem. Porém, no processo de pirólise estes catalisadores apresentam-se inéditos. Os pirolisatos obtidos foram caracterizados por GC-FID e GC/MS, e os gases produzidos foram quantificados e analisados por micro-GC. A utilização da atmosfera de gás hidrogênio não minimizou a produção de alcenos como produto da pirólise. A presença de água na biomassa otimizou o processo de craqueamento térmico. Este craqueamento quando realizado na presença dos catalisadores na temperatura de 550 °C mostrou um rendimento maior de biocombustível líquido com hidrocarbonetos na faixa de C9 a C16 (aproximadamente 37%) em relação ao tratamento não catalítico. A análise semi-quantitativa dos gases produzidos na pirólise sugere as rotas de descarboxilação (pela presença de CO2) e descarbonilação (pela presença de CO) durante o craqueamento térmico catalítico, além de evidenciar a ocorrência do processo Fischer-Tropsch produzindo hidrocarbonetos na faixa do querosene.
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Termovalorização da biomassa de aguapé (Eichhornia crassipes) através de pirólise em reator forno rotativo / Thermovalorisation of water hyacinth (Eicchornia crassipes) biomass through pyrolysis in rotary kiln reactor

Carregosa, Ingred Suellen Carvalho 27 July 2016 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Lignocellulosic biomass use for obtaining biofuels has been showing itself with much more evidence during these past years through cellulosic ethanol and biooils, biogases and biochars. Aquatic plants of lignocellulosic basis, Eichhornia crassipes species, commonly known by water hyacinth, represent a major environmental problem due to their invasive nature and their high proliferation rate. In this work we evaluated the possibility of use this biomass source from pyrolysis in a rotary kilns reactor in three different temperatures. The results evidence that the major yield of the liquid fraction (bio-oil + acid extract) was obtained at 500 ºC (42.11%). For 400 ºC and 600 ºC, the biochar and biogas had major production, 37.78% and 42.36%, respectively. Bio-oils characterization by GC/MS produced in microscale allowed an investigation upon the scale-up phenomenon under the bio-oils composition. The results show that, in qualitative terms, the chemical composition of bio-oils was not changed, however, at semiquantitative aspect, show they are produced in distinguish relative percentages. The mainly chemical classes identified in biooils were: acids, alcohols, phenols and sugar derivatives. Bio-oils showed in average, 68% of calorific power of the fuels derived from petroleum, glimpsing enforcement on the energetic area. In the produced biochars, with yields between 37% and 26%, the increase on pyrolysis temperature has provided an increase upon carbon concentration, and a decreasing upon the hydrogen and oxygen concentrations, reflecting in high aromaticity of the materials. These materials ware tested in some aspects about the soils management, nutritional function and water retention. In view of this, the water hyacinth pyrolysis has associated sustainability concepts and green chemistry, putting concepts of renewable energetic sources together and glimpsing an environmental problems inhibition, to offer an alternative to the 2nd generation of bio-fuels production. / O uso de biomassas lignocelulósicas para a obtenção de biocombustíveis apresenta-se com muito mais evidência nos últimos anos através do etanol celulósico e de bio-óleos, biogás e biocarvão. As plantas aquáticas de base lignocelulósica da espécie Eichhornia crassipes, popularmente conhecida por aguapé, representam um grande problema ambiental devido ao seu caráter invasor e sua alta taxa de proliferação. Neste trabalho avaliou-se a possibilidade de aproveitamento dessa fonte de biomassa a partir do processo de pirólise em um reator cilindro rotativo em três diferentes temperaturas. Os resultados demonstraram que o maior rendimento da fração líquida (bio-óleo + extrato ácido) foi obtido a 500 ºC (42,11%). Para as temperaturas de 400 e 600 ºC, o biocarvão e o biogás tiveram maior produção, 37,78% e 42,36%, respectivamente. A caracterização por CG/EM dos bio-óleos produzidos em microescala permitiram investigar o efeito de scale-up sob a composição dos bio-óleos. Os resultados mostraram que em termos qualitativos, a composição química dos bio-óleos não foi alterada, no entanto, no aspecto semiquantitativo mostraram que são produzidos em percentuais relativos distintos. As principais classes químicas identificadas nos bio-óleos foram: ácidos, álcoois, fenóis e derivados de açúcares. Os bio-óleos apresentaram em média 68% do poder calorífico do combustível derivado de petróleo, vislumbrando uma aplicação na área energética. Nos biocarvões produzidos, com rendimento variando de 37% a 26%, o aumento da temperatura de pirólise proporcionou um aumento na concentração de C, e uma diminuição nas concentrações de H e O, refletindo em maior aromaticidade dos materiais. Estes materiais foram testados sob alguns aspectos quanto ao manejo de solos, função nutricional e retenção de água. À vista disto, a pirólise de aguapé relacionou conceitos de sustentabilidade e química verde, unindo o conceito de fontes de energias renováveis com a inibição de problemas de cunho ambientais, ao oferecer uma biomassa alternativa para a produção de biocombustíveis de 2ª geração.
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Etude de la production de bio-huile par liquéfaction hydrothermale de résidus agroalimentaires et de leurs molécules modèles / Study of bio-oil production by hydrothermal liquefaction of food processing residues and their model compounds

Déniel, Maxime 07 November 2016 (has links)
Ce travail porte sur la production de bio-huile par liquéfaction hydrothermale de résidus agroalimentaires, réalisée en réacteur batch. L’objectif est d’étudier l’influence des paramètres opératoires sur la production de bio-huile, et de contribuer à la compréhension des mécanismes de conversion hydrothermale de la biomasse. La liquéfaction hydrothermale des résidus agroalimentaires a été étudiée à partir de l’exemple des drêches de cassis, résidus de pressage des baies. Une étude paramétrique a évalué l’influence de la température, du temps de réaction, de la concentration de biomasse et de l’ajout d’hydroxyde de sodium sur le rendement des produits. Cette étude a permis d’identifier des conditions opératoires favorables à la production de bio-huile, dont le rendement peut notamment bénéficier du recyclage de la phase aqueuse en tant que solvant réactionnel (rendement maximal de bio-huile : 31 %). La caractérisation physico-chimique de la bio-huile montre que celle-ci possède certaines propriétés proches du pétrole brut et de certains fiouls lourds, notamment grâce à sa faible teneur en oxygène en comparaison des huiles de pyrolyse. La bio-huile peut être considérée comme un bio-pétrole brut, mais nécessite toutefois un raffinage conséquent avant de potentielles applications. La conversion hydrothermale de molécules modèles, sélectionnées à partir de l’analyse de la composition des drêches de cassis, a été étudiée à une température de 300 °C et un temps de réaction de 60 min. Cinq monomères modèles (glucose, xylose, acide glutamique, guaiacol et acide linoléique) et deux polymères modèles (cellulose microcristalline et lignine alkali) ont été choisis pour cette étude. Une méthodologie basée sur les plans d’expérience de mélange a été mise en œuvre, afin d’aboutir à la construction de schémas réactionnels, et à l’élaboration de corrélations modélisant les rendements des produits en fonction de la composition initiale des mélanges. L’analyse des produits montre que la conversion hydrothermale des résidus agroalimentaires résulte principalement de dégradations primaires et d’interactions binaires entre les composants de la biomasse. Les corrélations obtenues à partir des composés modèles permettent de décrire avec un bon accord les rendements des produits de conversion hydrothermale de mélanges modèles et de plusieurs résidus agroalimentaires : drêches de brasserie, marc de raisin et akènes de framboise. / This work presents a study of hydrothermal liquefaction of food processing residues using a batch reactor, to produce bio-oil. The objective is to study the influence of operating conditions on bio-oil production, and to contribute to the understanding of the reaction mechanisms occurring during hydrothermal conversion of biomass. Hydrothermal liquefaction of food processing residues was studied using blackcurrant pomace, a berry pressing residue, as an example. A parametric study evaluated the influence of temperature, holding time, biomass concentration and the use of sodium hydroxide as additive on the yields of products. This study allowed the identification of favorable operating conditions to produce bio-oil. The bio-oil yield can in particular benefit from recycling the aqueous phase as reaction solvent (maximum bio-oil yield: 31%). Physicochemical characterization of the bio-oil showed that it has some similarities with heavy crude oil and heavy oils, especially thanks to a lower oxygen content than pyrolysis oils. The bio-oil can be considered as a bio-heavy crude oil, but it still requires significant upgrading before any potential applications. Hydrothermal conversion of model molecules, selected from the characterization of blackcurrant pomace, was studied at a temperature of 300 °C and a holding time of 60 min. Five model monomers (glucose, xylose, glutamic acid, guaiacol and linoleic acid) and two model polymers (microcrystalline cellulose and alkali lignin) were chosen for this study. A mixture design of experiments methodology was followed, to combine reactivity studies with the elaboration of correlations describing the mass yields of products as a function of the initial mixture composition. Analysis of the products shows that hydrothermal conversion of food processing residues is mainly due to degradations of individual compounds and binary interactions between components of biomass. The correlations obtained from the model compounds describe with good accuracy the mass yields of the products from hydrothermal conversion of a model mixture and several food processing residues: brewer’s spent grains, grape marc and raspberry achenes.

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