Reports indicate that the worldwide energy consumption and fossil fuel energy production level will have an opposite trend in the coming two decades. The former will continue to increase while the later will decrease. Therefore, additional sources of energy need to be developed. Field pennycress (Thlaspi, arvense L.) has been found to be an ideal source of energy because it has prolific yield and has no value as food. We demonstrated conventional and catalytic fast pyrolysis of whole pennycress biomass in a fluidized bed reactor. Characterization studies on field pennycress showed that the biomass had a potential to be converted to energy-rich bio-fuel. Thermogravimetric and kinetic study on field pennycress provided vital information on the degradation behavior of the feedstock. A parametric study was conducted on conventional rapid pyrolysis by using the effects model. The optimum experimental condition that gave maximum liquid yield was found to be at a temperature of 500 °C and a gas flow rate of 24 l/min. The catalysts used for catalytic fast pyrolysis were HZSM-5, a commercial catalyst, and red mud, an alumina industry waste material. The liquid products obtained from pennycress were found to have better qualities compared to a typical lignocellulosic feedstocks pyrolysis bio-oil. The bio-oil from the red mud catalyzed experiment had almost neutral pH of 6.5 and the pH in the case of HZSM-5 was 5.7. In comparison to bio-oil from conventional rapid pyrolysis, HZSM-5 and red mud reduced the viscosity of the bio-oil by 3 and 5 times, respectively. However, red mud was only found to be effective in improving the higher heating value (HHV) of the bio-oil from 33.18 MJ/kg (dry basis) in conventional pyrolysis to 35.7 MJ/Kg (dry basis). The HHV of HZSM-5 catalyzed bio-oil was 33.63 MJ/kg. The composition of non-condensable gases and the chemical makeup of the bio-oil from the two catalysts were different, suggesting that the reaction pathways could be different. HZSM-5 had higher selectivity for aromatics whereas red mud produced longer aliphatic chains. The bio-oil obtained from red mud catalytic pyrolysis of field pennycress is a promising alternative energy source that could replace petroleum fuels after some upgrading.

Biomassa innehåller oorganiska ämnen som bl.a. alkalimetaller och alkaliska jordartsmetaller, vilket bidrar till ett minskat utbyte av pyrolysolja och ökar istället utbytet av gaser och lågvärdiga produkter. Detta sker p.g.a. att oorganiska ämnen agerar som krackningkatalysatorer. [1] Pyrolysolja har även en hög syrehalt vilket t.ex. gör den oblandbar med fossil olja. Genom att använda lakning som förbehandlingsmetod kan biomassans innehåll av oorganiska ämnen minska och pyrolysoljans sammansättning ändras. Detta sker genom bl.a. jonbytesreaktioner som uppstår mellan joner i lakningsmedlet och biomassans oorganiska ämnen. [2]        En katalysator kan användas för att minska syrehalten i pyrolysoljan och erhålla högvärdiga produkter som aromater. Detta sker genom katalytiska reaktioner som bl.a. krackning, aromatisering, ketoniserings- och aldolkondensation samt avspjälkning av vatten. [3] [4] I detta arbete har kombinationen av att förbehandla biomassa samt att låta pyrolysångor reagera över en katalysator undersökts. Fyra olika experiment har utförts för att kunna jämföra produktfördelningen mellan vätska, gas och kolrest, vätskefördelningen mellan H2O och olja samt olje-sammansättningen i de olika fallen. Experimenten utfördes med förbehandlad/icke-förbehandlad biomassa med och utan katalysator. Som lakningsmedel vid förbehandlingen användes en blandning av ättiksyra och avjoniserat vatten som biomassan behandlades med och sedan separerades ifrån. Som katalysator användes zeoliten HZSM-5 och utvärderades ex-bed i pyrolysören.        Resultaten visar att halten oorganiska ämnen minskar efter behandling. Förbehandlad biomassa utan katalysator ger ett ökat utbyte av vätska där vätskefördelningen mellan H2O och olja visar en större mängd olja jämfört med icke-förbehandlad biomassa utan katalysator. I fallet förbehandlad biomassan med katalysator visar resultatet att en större mängd gas bildas jämfört med icke-förbehandlad biomassa med katalysator, vilket tyder på att katalysatorn reagerar starkare mot sammansättningen av pyrolysångor från förbehandlad biomassa i det fallet. Vätskefördelningen vid icke-förbehandlad biomassan med katalysator visar en större mängd olja jämfört med förbehandlad biomassa med katalysator.       Olje-sammansättningen visar att den största mängden högvärdiga produkter, i detta fall polyaromatiska kolväten, bildas vid närvaro av katalysator. / Biomass generally contains inorganic substances such as alkali metals and alkaline earth metals, which reduce the yield of pyrolysis oil and increases the yield of gases and low-value products due to inorganic substances acting as cracking catalysts. [1] Pyrolysis oil also has a high oxygen content, making it im-miscible with fossil oil. Using leaching as a pretreatment method, the content of inorganic substances in biomass can decrease which changes the composition of the pyrolysis oil. Among other things, this occurs through ion-exchange reactions that occur when ions between the leachant and the ionically bonded inorganic elements in biomass change site. [2] A catalyst can be used to reduce oxygen content in the pyrolysis oil and obtain high-quality products such as aromatics. This is done through reactions such as cracking, aromatization, ketonization and aldol condensation as well as hydro-deoxygenation that arise in the presence of a catalyst. [3] [4]            In this work, four different experiments have been conducted to compare the product distribution between liquid, gas and char, the liquid distribution between H2O and oil and the oil composition in the different cases. The experiments were performed with pre-treated/untreated biomass with and without catalyst. As leachant, a mixture of acetic acid and deionized water was used with which the biomass was boiled and then separated. As catalyst, The zeolite HZSM-5 was used. HZSM-5 was evaluated ex-bed in the process. The results show that the content of inorganic substances decreases after treatment. Pre-treated biomass without catalytic upgrading leads to increase in the liquid yield in which the liquid distribution between H2O and oil shows a greater amount of oil compares to untreated biomass with without catalytic upgrading, indicating a decrease of inorganic substances. In the case of pre-treated biomass with catalyst, the result shows that a larger amount of gas is formed compared to untreated biomass with catalyst, which indicates that the catalyst reacts more strongly to the composition of pyrolysis vapors from a pre-treated biomass in that case. The liquid distribution of the untreated biomass with catalyst shows a greater amount of oil compared to pre-treated biomass with catalyst.       The oil composition shows that the largest amount of high-value products, in this case polyaromatic hydrocarbons, is formed in the presence of the catalyst.

The fractional catalytic pyrolysis of pine was studied both experimentally and through models. A preliminary stage economic analysis was conducted for a wood chip pyrolysis facility operating at a feed rate of 2000 wet ton/day for producing bio-oil. In the experimental study, multiple grams of bio oil were produced in a single run to facilitate the more extensive characterization of the oil produced from pyrolysis of biomass impregnated with different catalysts. Two reactors configurations, a screw extruder and a tubular pyrolysis reactor, were explored to perform fractional catalytic pyrolysis of biomass. The main aim of performing a wood pyrolysis reaction in a modified screw extruder is to facilitate the simultaneous collection of bio-oil produced from staged temperature pyrolysis of three main components of wood, cellulose, hemicellulose and lignin, at a reasonable scale. Apart from complete characterization of bio-oil, this will enable us to study the effect of various selected catalysts on the quality of bio-oil and the percentage of char produced, and the influence of process parameters on chemical composition of the pyrolysis oils. These experiments were later performed in a tubular pyrolysis reactor due to the difficulty of making different parts of the extruder work well together. The goal of these experiments is to produce bio-oil in multiple grams from fractional catalytic pyrolysis of wood. This will enable us to study the effect of catalyst on the chemical composition of the oil and percentage of char produced. In the modeling studies, a model of an auger reactor comprised of three different zones run at different temperatures to facilitate the collection of oil from pyrolysis of three major components of wood, namely cellulose, hemicelluloses and lignin, was developed. The effect of residence time distribution (RTD), and zone temperatures based on kinetic models on the yield of products was studied. Sensitivity of the Arrhenius rate constants calculated from synthetic data with respect to small variations in process parameters was evaluated. In the economic analysis of a wood chip pyrolysis facility, mass and energy calculations were performed based on a feed rate of 2000 wet tons/day of wood chips to the dryer. The cost of bio-oil at 10% return on investment was proposed and the sensitivity of the selling price of bio-oil with respect to capital and operating costs was analyzed. The experimental study will serve as a benchmark in exploring the above mentioned reactor configurations further. Alkali metal carbonates were used to study the quality of oil produced from pine pyrolysis. It was established that these catalysts, when added in the same molar ratio basis, increase the percentage of char. However, complete characterization of these oils for different catalysts needs to be done. Systems modeling of pyrolysis in an auger reactor established that the kinetic parameters (depending on experimental set up) and the RTD (Residence Time Distribution) parameters play a crucial role in determining the yield of oil. Variations in temperature of zone 3 play a crucial role in varying the output of oil whereas variations in temperatures of zones 2 and 1 do not significantly impact the output of oil. For a given reaction kinetic scheme for the pyrolysis reactions, calculated values of the kinetic rate constants are not sensitive to errors in experimental conditions. It was also established that the experimental error in calculation of the RTD parameters can induce error in calculation of the Arrhenius constants but these values can still predict the yield of products accurately. In the economic analysis of wood chip pyrolysis, the selling price of the bio-oil according to the cost calculation is projected to be $1.49/gal. The production cost of bio-oil is $ 1.20/gal. The cost of bio-oil is extremely sensitive to variations in operating cost (for example, cost of feed stock and selling price of char) and is not significantly affected by the variations in capital cost.

The rising fuel prices, environmental concerns over the emission of greenhouse gases, and the limited availability of fossil fuels led to the current focus on developing alternative fuel sources that are sustainable and environmentally benign. Lignocellulosic biomass, due to its high carbon value, abundance and for being greenhouse gas neutral, is a promising alternative energy resource. Fast pyrolysis of lignocellulosic biomass produces high energy density liquid fuel, called bio-oil, which has the potential as transportation fuel. But, crude bio-oils are chemically complex liquids with high oxygen contents (40 % oxygen content), high viscosity, low pH, low thermal stability, and poor heating values (20 MJ/Kg). Therefore, bio-oils must be substantially upgraded (de-oxygenated) to highly stable, non-corrosive, and high calorific value liquid fuels prior to their use as transportation fuels. This research was conducted to investigate the efficiency of various acid catalysts in upgrading (cracking) the oxygenated pine wood pyrolysis vapors to high quality liquid fuel. Initial catalyst screening studies proved that zeolite acidity and pore structure is essential for effective cracking of pyrolysis vapors. Low space velocities and moderate temperatures were found to be favorable for the deoxygenation of pyrolysis vapors. Various zeolites were tested, of which HZSM-5 with low Si/Al ratio was found to be an effective cracking catalyst. But the use of zeolites resulted in poor liquid yields. Zeolites were promoted with transition metal ions in order to inhibit the secondary cracking reactions occurring on Brönsted acid sites. The metal-promoted biunctional catalysts were found to be the most effective catalysts, among all the catalysts employed in this research, in promoting hydrocarbon forming reactions without adversely affecting the liquid yields. Catalyst coking was unavoidable but the addition of metal ions to zeolites lowered the extent of coking. TG analysis of used catalysts indicated that the catalysts can be regenerated by calcining at 600-650 °C.

Made available in DSpace on 2014-12-17T14:07:15Z (GMT). No. of bitstreams: 1 MariaSBF_TESE.pdf: 2706042 bytes, checksum: e909d3cb5ee177d47cc6917725b38335 (MD5) Previous issue date: 2013-05-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In recent years, the area of advanced materials has been considerably, especially when it comes to materials for industrial use, such as is the case with structured porosity of catalysts suitable for catalytic processes. The use of catalysts combined with the fast pyrolysis process is an alternative to the oxygenate production of high added value, because, in addition to increasing the yield and quality of products, allows you to manipulate the selectivity to a product of interest, and therefore allows greater control over the characteristics of the final product. Based on these arguments, in this work were prepared titanium catalysts supported on MCM-41 for use in catalytic pyrolysis of biomass, called elephant grass. The reactions of pyrolysis of biomass were performed in a micro pyrolyzer, Py-5200, coupled to GC / MS, the company CDS Corporation, headquartered in the United States. The catalysts Ti-MCM-41 in different molar ratios were characterized by XRD, TG / DTG, FT-IR, SEM, XRF, UV-visible adsorption of nitrogen and the distribution of particle diameter and specific surface area measurement by the BET method. From the catalytic tests it was observed that the catalysts synthesized showed good results for the pyrolysis reaction.The main products were obtained a higher yield of aldehydes, ketones and furan. It was observed that the best reactivity is a direct function of the ratio Si/Ti, nature and concentration of the active species on mesoporous supports. Among the catalysts Ti-MCM-41 (molar ratio Si / Ti = 25 and 50), the ratio Si / Ti = 25 (400 ? C and 600 ? C) favored the cracking of oxygenates such as acids , aldehydes, ketones, furans and esters. Already the sample ratio Si / Ti = 50 had the highest yield of aromatic oxygenates / Nos ?ltimos anos, a ?rea de materiais tem avan?ado consideravelmente, principalmente, quando se trata de materiais para uso industrial, como ? o caso de catalisadores estruturados com porosidade adequada para os processos catal?ticos. O uso de catalisadores combinados ao processo de pir?lise r?pida ? uma alternativa para a produ??o de compostos oxigenados de alto valor agregado, pois, al?m de elevar o rendimento e qualidade dos produtos, permite manipular a seletividade para um produto de interesse e, portanto, permite um maior controle sobre as caracter?sticas do produto final. Com base nesses argumentos, neste trabalho foram preparados catalisadores de tit?nio suportados em MCM-41 para uso em pir?lise catal?tica da biomassa, denominada de capim elefante. As rea??es de pir?lise da biomassa foram realizadas em um micro pirolisador, Py-5200, acoplado ao GC/MS, da empresa CDS Corporation, sediada nos Estados Unidos. Os catalisadores Ti-MCM-41, em diferentes raz?es molares, foram caracterizados por DRX, TG/DTG, FT-IR, MEV, FRX, UV-Vis?vel, adsor??o de nitrog?nio, distribui??o de di?metro de part?culas e medidas de ?rea espec?fica pelo m?todo BET. A partir dos testes catal?ticos foi poss?vel observar que os catalisadores sintetizados apresentaram bons resultados para a rea??o de pir?lise. Entre os catalisadores Ti-MCM-41 (raz?es molares Si/Ti = 25 e 50), o de raz?o Si/Ti=25 (temperatura de 400?C e 600?C) favoreceu o craqueamento de compostos oxigenados, tais como, ?cidos, alde?dos, cetonas, furanos e ?steres. J? a amostra de raz?o Si/Ti = 50 apresentou maior rendimento de arom?ticos oxigenados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nowadays, one of the major challenges worldwide is the reduction of greenhouse gas emissions, whose contribution to climatic changes was comproved. The emissions of carbon dioxide from the burning of fossile fuels are the main factor that increases the global warming. Biodiesel is a biodegradable fuel derived from renewable sources that can be obtained by different processes such as pyrolysis, esterification or even transesterification. The pyrolysis reactions refer to the rupture of carbon-carbon binding in hydrocarbons molecules. This reaction is an endothermic process and, therefore, thermodynamically favored by high temperatures and low pressures. The present work has as objective to studiy the thermal and catalytic pyrolysis of soy oil, using acid mesoporosous heterogeneous catalysts (HAlMCM-41). The synthesis and characterization of AlMCM-41 and HAlMCM-41 was performed with different Si/Al ratios. The sample of AlMCM-41 was synthesized by hydrothermal method after that it was submitted to a process of ion exchange to generate the acidic form HAlMCM-41. The catalysts were characterized by X-ray diffraction (XRD) and infrared spectroscopy (IR). Based on the results obtained by infrared spectroscopy analysis, it was possible to indentify the main bands on the structure of AlMCM-41, demonstrating that the calcination method was promising in the elimination of the organic activating substituent. The results of X-ray diffraction showed that the AlMCM-41 was synthesized successfully and with high degree of hexagonal ordination to different Si/Al ratios. A comparative study between thermal pyrolysis and catalytic pyrolysis of refined soybean oil, over catalyst HAlMCM-41 synthesized with different Si/Al ratios, was carried out aiming to study the influence of this catalyst on the conversion rates and in the pyrolysis reaction s activation energy. The results show that mesoporosos catalysts were obtained and that the Si/Al rate of best catalytic activity was equal to 60. / Um dos principais desafios mundiais está relacionado à redução dos gases causadores do efeito estufa, cuja contribuição nas mudanças climáticas já foi comprovada. A emissão de dióxido de carbono proveniente da queima de combustíveis fósseis é o principal fator que contribui para o aumento do aquecimento global. O biodiesel é um combustível biodegradável derivado de fontes renováveis, que pode ser obtido por diferentes processos tais como a pirólise, a esterificação ou pela transesterificação. As reações de pirólise referem-se à ruptura da ligação carbono-carbono dos hidrocarbonetos mediante a ação de energia térmica. Essa reação constitui um processo endotérmico, sendo favorecida termodinamicamente por altas temperaturas e baixas pressões. O presente trabalho tem como objetivo estudar a pirólise convencional e catalítica de óleo de soja, utilizando catalisadores heterogêneos mesoporosos ácidos (HAlMCM-41). Foi realizada a síntese e caracterização do AlMCM-41 e HAlMCM-41 com diferentes razões de Si/Al. A amostra de AlMCM-41 foi sintetizada pelo método hidrotérmico, e em seguida, submetida a um processo de troca iônica para geração da forma ácida HAlMCM-41. Os catalisadores obtidos foram caracterizados por difração de raios-X (DRX) e espectroscopia na região do infravermelho (IV). Com base nos resultados obtidos na análise de espectroscopia na região do infravermelho, foi possível identificar as principais bandas relativas à estrutura do AlMCM-41, demonstrando que o método de calcinação foi promissor na eliminação do direcionador orgânico. Os resultados das análises de difração de raios-X mostraram que o AlMCM-41 foi sintetizado com sucesso e com alto grau de ordenação hexagonal nas diferentes razões Si/Al. Um estudo comparativo entre a pirólise convencional e a catalítica de óleo de soja refinado, sobre catalisador HAlMCM-41, foi realizado com o objetivo de estudar a influência desse catalisador nas taxas de conversão e na energia de ativação das reações de pirólise. Os resultados mostram que se obteve catalisadores mesoporosos e que a razão Si/Al de melhor atividade catalítica foi a de 60.

Catalytic pyrolysis technology is one of the thermochemical platforms used to produce high quality bio-oil and chemicals from biomass feedstocks. In the catalytic pyrolysis process, the biomass is rapidly heated under inert atmosphere in the presence of an acid catalyst or zeolite to promote deoxygenation and cracking of the primary vapors into hydrocarbons and small oxygenates. This dissertation examines the utilization of conventional fluid catalytic cracking (FCC) catalyst in the fractional catalytic pyrolysis of hybrid poplar wood. The influence of Y-zeolite content, steam treatment, addition of ZSM-5 additive, process conditions (temperature, weight hourly space velocity (WHSV) and vapor residence time) and recycling of the non-condensable gases (NCG) on the product distribution and the quality of the bio-oil were investigated. The first part of the study demonstrates the influence of catalytic property of FCC catalyst on the product distribution and quality of the bio-oil. It was found that FCC catalyst with higher Y-zeolite content produces higher coke yield and lower organic liquid fraction (OLF). Conversely, FCC catalyst with lower Y-zeolite content results in lower coke yield and higher OLF. The results showed that higher Y-zeolite content extensively cracks dehydrated products from cellulose decomposition and demethoxylates phenolic compounds from lignin degradation. The Y-zeolite promoted both deoxygenation and coke forming reactions due to its high catalytic activity and large pore size. Higher Y-zeolite content increased the quality of the bio-oil with respect to higher heating value (HHV), pH, density, and viscosity. The steam treatment at 732 oC and 788 oC decreased the total BET surface area of the FCC catalyst. The findings suggest that steam treatment reduces the coking tendency of the FCC catalyst and enhances the yield of the OLF. Analysis of the bio-oils showed that the steamed FCC catalyst produces bio-oil with lower viscosity and density. Gas chromatography and 13C-NMR spectrometry suggest that steam treatment affect the catalyst selectivity in the formation of CO, CO2, H2, CH4, C2-C5 hydrocarbons and aromatic hydrocarbons. The addition of ZSM-5 additive to the FCC catalyst was found to alter the characteristic/functionality of the catalytic medium. The product slate showed decrease in coke yield and increase in OLF with increase in ZSM-5 additive. The FCC/ZSM-5 additive hybrid catalysts produced bio-oils with relatively lower viscosity and higher pH value. The formation of CO2, CH4, and H2 decreased whilst C5 and aromatic hydrocarbons increased with increase in ZSM-5 additive level. The second part of the work assesses the effect of operating conditions on the catalytic pyrolysis process. The response surface methodology study showed reaction temperature to be the most influential statistically significant independent variable on char/coke yield, concentration of non-condensable gases, carbon content, oxygen content, pH and viscosity of the bio-oils. The WHSV was the most important statistically significant independent variable that affects the yield of organic liquid and water. Adequate and statistically significant models were generated for the prediction of the responses with the exception of viscosity. Recycling of the NCG in the process was found to potentially increase the liquid yield and decrease char/coke yield. The experiments with the model fluidizing gases showed that CO/N2, CO2/N2, CO/CO2/N2 and H2/N2 increase the liquid yield and CO2/N2 decrease char/coke yield. The results showed that recycling of NCG increases the higher heating value and the pH of the bio-oil as well as decreases the viscosity and density. The concept of recycling the NCG in the catalytic cracking of biomass vapors with FCC catalyst improved the overall process. The evaluation of the reactivity of conventional FCC catalyst towards bio-based molecules provide essential direction for FCC catalyst formulation and design for the production of high quality bio-oils from catalytic pyrolysis of biomass. / Ph. D.

Made available in DSpace on 2014-12-17T14:09:14Z (GMT). No. of bitstreams: 1 RenataMB_TESE.pdf: 1339744 bytes, checksum: 24902b1b3636b97bbd787863d62c1f99 (MD5) Previous issue date: 2012-08-09 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The fast pyrolysis of lignocellulosic biomass is a thermochemical conversion process for production energy which have been very atratactive due to energetic use of its products: gas (CO, CO2, H2, CH4, etc.), liquid (bio-oil) and charcoal. The bio-oil is the main product of fast pyrolysis, and its final composition and characteristics is intrinsically related to quality of biomass (ash disposal, moisture, content of cellulose, hemicellulose and lignin) and efficiency removal of oxygen compounds that cause undesirable features such as increased viscosity, instability, corrosiveness and low calorific value. The oxygenates are originated in the conventional process of biomass pyrolysis, where the use of solid catalysts allows minimization of these products by improving the bio-oil quality. The present study aims to evaluate the products of catalytic pyrolysis of elephant grass (Pennisetum purpureum Schum) using solid catalysts as tungsten oxides, supported or not in mesoporous materials like MCM-41, derived silica from rice husk ash, aimed to reduce oxygenates produced in pyrolysis. The biomasss treatment by washing with heated water (CEL) or washing with acid solution (CELix) and application of tungsten catalysts on vapors from the pyrolysis process was designed to improve the pyrolysis products quality. Conventional and catalytic pyrolysis of biomass was performed in a micro-pyrolyzer, Py-5200, coupled to GC/MS. The synthesized catalysts were characterized by X ray diffraction, infrared spectroscopy, X ray fluorescence, temperature programmed reduction and thermogravimetric analysis. Kinetic studies applying the Flynn and Wall model were performed in order to evaluate the apparent activation energy of holoceluloce thermal decomposition on samples elephant grass (CE, CEL and CELix). The results show the effectiveness of the treatment process, reducing the ash content, and were also observed decrease in the apparent activation energy of these samples. The catalytic pyrolysis process converted most of the oxygenate componds in aromatics such as benzene, toluene, ethylbenzene, etc / A pir?lise r?pida da biomassa lignocelul?sica ? um processo de convers?o termoqu?mica para produ??o de energia que vem se tornando muito atratativo devido ao aproveitamento energ?tico de seus produtos: g?s (CO, CO2, H2, CH4, etc), l?quido (bio-?leo) e carv?o vegetal. O bio-?leo ? o principal produto da pir?lise r?pida, sendo a sua composi??o e caracter?sticas finais intrinsecamente relacionadas ? qualidade da biomassa (elimina??o de cinzas, teor de umidade, teor de celulose, hemicelulose e lignina) bem como ? efici?ncia da remo??o dos compostos oxigenados que causam caracter?sticas indesej?veis como aumento da viscosidade, instabilidade, corrosividade e baixo poder calor?fico. Os compostos oxigenados s?o originados no processo de pir?lise convencional da biomassa onde o uso de catalisadores s?lidos, em geral, permite a minimiza??o destes produtos melhorando a qualidade do produto final, o bio-?leo. O presente trabalho teve como objetivo avaliar os produtos da pir?lise catal?tica do capim elefante (Pennisetum purpureum Schum) utilizando catalisadores s?lidos, ?xidos a base de tungst?nio, suportados ou n?o em materiais mesoporosos do tipo MCM-41, derivados da s?lica da casca do arroz, visando ? redu??o de compostos oxigenados produzidos na pir?lise. O tratamento da biomasssa atrav?s da lavagem com ?gua aquecida (CEL) ou lavagem com solu??o ?cida (CELix), bem como a aplica??o de catalisadores a base de tungst?nio nos vapores provenientes do processo de pir?lise, teve a finalidade de melhorar a qualidade dos produtos da pir?lise. A pir?lise convencional e catal?tica da biomassa foram realizadas em um micro pirolisador, Py-5200, acoplado ao GC/MS. Os catalisadores sintetizados foram caracterizados por Difra??o de raios X, Espectroscopia na regi?o do infravermelho, Fluoresc?ncia de Raios X, Redu??o por Temperatura Programada e An?lise termogravim?trica. Estudos cin?ticos aplicando o modelo de Flynn Wall foram realizados com a finalidade de avaliar a energia de ativa??o aparente da decomposi??o t?rmica da holoceluloce nas amostras de capim elefante (CE, CEL e CELix). Os resultados mostraram a efici?ncia do processo de tratamento, reduzindo o teor de cinzas, como tamb?m foi observada a diminui??o na energia de ativa??o aparente dessas amostras. O processo de pir?lise catal?tica converteu a maioria dos produtos oxigenados do CE em arom?ticos como benzeno, tolueno, etilbenzeno, etc

La consommation continue de matières plastiques a conduit, jusqu’à 2015, à l'accumulation de 6,3 milliards de tonnes de déchets plastiques. En Europe, le recyclage des plastiques ramassés ne dépasse pas les 30% pour des raisons logistiques et économiques liées à cette filière. La valorisation énergétique de ces déchets, non valables pour le recyclage, est alors préférée aux autres modes de gestion. L’incinération étant controversée pour son bilan énergétique et environnemental, d’autres moyens de valorisation tels que la pyrolyse sont privilégiés. Les travaux de recherche menés dans cette thèse ont été focalisés sur la pyrolyse des polyoléfines, le polyéthylène (PE) et le polypropylène (PP), en raison de leur forte présence dans les déchets plastiques municipaux. L’influence de la zéolithe Ultrastable Y (USY) sur la pyrolyse du PP et du PE, récupérés d’une déchèterie, a été étudiée par une analyse thermogravimétrique (ATG) puis sur un réacteur en batch à lit fixe et un réacteur continu. L’étude cinétique dedécomposition thermique des mélanges de PP et de PE a été réalisée, les paramètres cinétiques ont été déterminés et les interactions entre les différents composants du mélange ont été analysées. La quantité de zéolithe a été optimisée et le rapport catalyseur/plastique de 1:10 a été adopté durant les essais expérimentaux. L’utilisation de l’USY comme catalyseur a conduit à une distribution plus ciblée de composés et des temps de réaction plus courts. Les liquides de pyrolyse obtenus ont été séparés en différentes fractions de carburants compatibles avec les normes Européennes EN 590 et EN 228. Afin de réduire le coût de production de ces carburants, une étude de régénération du catalyseur a été menée et a montré que son niveau d’activité a diminué au bout de 14 cycles de régénération. A la fin de la thèse, un bilan d’énergie et de masse du procédé a été effectué puis les perspectives d’amélioration sont présentées afin de transposer l’étude à l’échelle industrielle. / Continuous consumption of plastics led, until 2015, to the accumulation of 6.3 billion tons of plastic waste. In Europe, the recycling of collected plastics does not exceed 30% for logistical and economic reasons related to this sector. The energy recoveryof this waste, which is not valid for recycling, is then preferred to other management methods. Incineration is controversial for its energy and environmental balance; other means of recovery such as pyrolysis are preferred. The research carried out in this thesis focused on the pyrolysis of polyolefins, polyethylene (PE) and polypropylene (PP), because of their strong presence in municipal plastic waste. The influence of the ultrastable Y zeolite (USY) on the pyrolysis of PP and PE, recovered from a waste collection center, was studied by thermogravimetric analysis (TGA) and then on a fixed bed batch reactor and a continuous reactor. The kinetic study of thermal decomposition of the PP and PE mixtures was carried out, the kinetic parameters were determined and the interactions between the various components of the mixture were analyzed. The amount of zeolite was optimized and the catalyst/plastic ratio of 1:10 was adopted during the experimental tests. The use of USY as a catalyst has led to a more targeted distribution of compounds and shorter reaction times. The pyrolysis liquids obtained were separated into different fuel fractions compatible with the European standards EN 590 and EN 228. In order to reduce the production cost of these fuels, a catalystregeneration study was conducted and showed that its activity level decreased after 14 cycles of regeneration. At the end of the thesis, an energy and mass balance of the process was carried out and the prospects for improvement are presented in order to transpose the study on an industrial scale.

Made available in DSpace on 2014-12-17T15:42:27Z (GMT). No. of bitstreams: 1 KesiaKVC_TESE.pdf: 1888403 bytes, checksum: 628d99fa0e77dc19c5054fa5d201217e (MD5) Previous issue date: 2013-04-17 / In this work were synthesized and characterized the materials mesoporous SBA-15 and Al- SBA-15, Si / Al = 25, 50 and 75, discovered by researchers at the University of California- Santa Barbara, USA, with pore diameters ranging from 2 to 30 nm and wall thickness from 3.1 to 6.4 nm, making these promising materials in the field of catalysis, particularly for petroleum refining (catalytic cracking), as their mesopores facilitate access of the molecules constituting the oil to active sites, thereby increasing the production of hydrocarbons in the range of light and medium. To verify that the materials used as catalysts were successfully synthesized, they were characterized using techniques of X-ray diffraction (XRD), absorption spectroscopy in the infrared Fourier transform (FT-IR) and adsorption nitrogen (BET). Aiming to check the catalytic activity thereof, a sample of atmospheric residue oil (ATR) from the pole Guamar?-RN was performed the process by means of thermogravimetry and thermal degradation of catalytic residue. Upon the curves, it was observed a reduction in the onset temperature of the decomposition process of catalytic ATR. For the kinetic model proposed by Flynn-Wall yielded some parameters to determine the apparent activation energy of decomposition, being shown the efficiency of mesoporous materials, since there was a decrease in the activation energy for the reactions using catalysts. The ATR was also subjected to pyrolysis process using a pyrolyzer with gas chromatography coupled to a mass spectrometer. Through the chromatograms obtained, there was an increase in the yield of the compounds in the range of gasoline and diesel from the catalytic pyrolysis, with emphasis on Al-SBA-15 (Si / Al = 25), which showed a percentage higher than the other catalysts. These results are due to the fact that the synthesized materials exhibit specific properties for application in the process of pyrolysis of complex molecules and high molecular weight as constituents of the ATR / No presente trabalho foram sintetizados e caracterizados os materiais mesoporosos SBA-15 e Al-SBA-15, Si/Al= 25, 50 e 75, descobertos por pesquisadores da Universidade da Calif?rnia- Santa B?rbara- EUA, tendo di?metro de poros variando entre 2 a 30 nm e espessura das paredes de 3,1 - 6,4 nm, tornando estes materiais promissores na ?rea da cat?lise, especificamente para o refino do petr?leo (craqueamento catal?tico), j? que seus mesoporos facilitam o acesso das mol?culas constituintes do petr?leo aos s?tios ativos, aumentando assim a produ??o de produtos na faixa dos hidrocarbonetos leves e m?dios. Para verificar se os materiais utilizados como catalisadores haviam sido sintetizados com sucesso, os mesmos foram caracterizados atrav?s das t?cnicas de difra??o de raios-X (DRX), espectroscopia de absor??o na regi?o do infravermelho com transformada de Fourier (FTIR) e adsor??o de nitrog?nio (BET). Com o intuito de verificar a atividade catal?tica dos mesmos, utilizou-se uma amostra de Res?duo Atmosf?rico de petr?leo (RAT), proveniente do P?lo de Guamar?- RN, realizando-se atrav?s da termogravimetria o processo de degrada??o t?rmica e catal?tica do res?duo. Mediante as curvas obtidas, observou-se uma redu??o na temperatura de in?cio do processo de decomposi??o catal?tica do RAT. Pelo modelo cin?tico proposto por Flynn- Wall obtiveram-se alguns par?metros para determina??o da energia de ativa??o aparente das decomposi??es, ficando evidenciada a efici?ncia dos materiais mesoporosos, j? que houve uma diminui??o da energia de ativa??o para as rea??es utilizando os catalisadores. O RAT tamb?m foi submetido ao processo de pir?lise utilizando-se um pirolisador com cromatografia gasosa, acoplado a um espectr?metro de massa. Mediante os cromatogramas obtidos, observou-se um aumento no rendimento dos compostos na faixa da gasolina e diesel oriundos da pir?lise catal?tica, com ?nfase para o Al-SBA-15 (Si/Al= 25), que apresentou um percentual superior aos demais catalisadores. Esses resultados se devem ao fato dos materiais sintetizados exibirem propriedades espec?ficas, para aplica??o no processo de pir?lise de mol?culas complexas e com alto peso molecular, como os constituintes do RAT