A velocidade de queima laminar adiabática é um importante parâmetro da combustão que dita o comportamento de chamas pré-misturadas. Dos métodos disponíveis para a medição desse parâmetro, o método do fluxo de calor destaca-se pela simplicidade e precisão. No presente trabalho, esse método é utilizado para medir a velocidade de queima de biogás (modelado como CH4 com diferentes níveis de diluição com CO2) e de gás de síntese (modelado como uma mistura de CH4, H2, CO, CO2 e N2) em ar a 298 K e 1 atm. Tais gases são de crescente interesse para a sociedade em função de aspectos ambientais, porém, suas velocidades de queima não foram amplamente estudadas ainda. Os resultados obtidos são comparados com as previsões de cinco mecanismos cinéticos (GRI-Mech 3.0, Davis et al., Konnov, San Diego e USC Mech II) a fim de avaliar a sua capacidade preditiva. Os resultados experimentais e numéricos das velocidades de queima de biogás e ar apresentam uma boa concordância e as incertezas encontradas foram condizentes com as relatadas na literatura. Os resultados experimentais desse gás foram parametrizados em uma correlação empírica de fácil utilização em modelos numéricos. As medições da velocidade de queima de gás de síntese e ar, por outro lado, apresentaram valores inferiores às previsões numéricas de todos os mecanismos estudados. Os dados experimentais da literatura, para a mesma mistura, diferem tanto em valores quanto em comportamento dos resultados do presente trabalho. Tal comportamento está provavelmente relacionado a alguma contaminação no CO utilizado, já que quando esse gás está presente observa-se uma chemi-luminescência não relatada na literatura. / The adiabatic laminar burning velocity is an important combustion parameter that dictates premixed flames characteristics. Among the measuring methods available in literature, the heat flux method stands out for its simplicity and accuracy. In the present work, this method is used to measure the adiabatic laminar burning velocity of biogas (modeled as CH4 with different dilution levels with CO2) and syngas (modeled as a CH4, H2, CO, CO2 and N2 mixture) in air at 298 K and 1 atm. Such gases are of growing society interest due to environmental aspects, however, their adiabatic laminar burning velocity have not been widely studied yet. The experimental results are compared to predictions of five kinetic mechanisms (GRI-Mech 3.0, Davis et al., Konnov, San Diego e USC Mech II) to evaluate their predictive capacity. Experimental and numerical results of biogas/air mixtures adiabatic laminar burning velocity show good agreement and the found uncertainties are in agreement with literature. Experimental results of this gas were fitted in an empiric correlation of simple numerical application. Experimental results of the laminar burning velocity of syngas/air, on the other hand, show lower values than the numerical predictions of all studied kinetic mechanisms. Literature available data for the same mixture differ both in values and behavior of the present work results. Such behavior is probably related to some contamination on the CO used since a chemi-luminescence not reported in literature can be noted when this gas is present.

Made available in DSpace on 2016-06-02T19:57:00Z (GMT). No. of bitstreams: 1 6808.pdf: 4907992 bytes, checksum: 8dda1b97e1ed03238369951b622517f4 (MD5) Previous issue date: 2015-03-18 / In this work, catalysts derived from hydrotalcites were employed in Direct Reforming of Biogas, once they feature the necessary basicity to allow and improve carbon removal during reforming. As a differential study, the effect of the step ageing elimination during hydrotalcites syntheses, which were prepared by means of coprecipitation technique, was also evaluated. The results obtained from temperature effect evaluation tests ranging from 800 to 500oC suggested there was no need of precursors ageing, which represents an energy saving during catalysts syntheses, once this step represents the most energy expensive. To improve the process and reduce carbon deposition, oxygen was added as synthetic air into the gaseous reactants feed, in a reaction known as Oxidative Reforming of Biogas. In this case, the ratio H2/CO was close to 1, along the temperature range from 800 to 500oC considered during the catalytic tests, which was assigned to the occurrence of methane partial oxidation, specially in lower temperatures. As an attempt to improve carbon gasification during reforming reactions, element cerium was also added during the syntheses of hydrotalcites, also by coprecipitation, fixing the amount of this element and ranging nickel amount, eliminating the step ageing. At this point, cerium promoted and unpromoted catalysts were compared through biogas direct reforming 6 hours stability tests at 650oC. The spent catalysts were characterized by thermogravimetric analysis in order to evaluate the amount of carbon deposited over the catalyst surface. It was found for the catalysts derived from oxides corresponding to 5 and 15% of nickel (% nominal, in weight) a higher carbon deposition at the presence of cerium promoted catalysts, although for the first one, the carbon temperature peak removal was lower than unpromoted catalyst. On the contrary, for the catalysts corresponding to 10 and 25% of nickel (% nominal, in weight), similar and lower carbon deposition was found in presence of cerium. It was also possible to confirm the reduction of carbon deposition after stability tests for oxidative reforming of biogas, compared to the direct reforming. / Neste trabalho, catalisadores derivados de hidrotalcitas foram empregados na reforma do biogás, uma vez que apresentam a basicidade que permite aprimoramento na remoção deste carbono durante a reação. O efeito da eliminação da etapa de envelhecimento das hidrotalcitas durante a síntese das mesmas, as quais foram preparadas pela técnica da coprecipitação, foi avaliado como um estudo diferencial. Os resultados obtidos a partir dos ensaios a patamares de temperatura na faixa de 800 a 500oC sugeriram que não há necessidade de envelhecimento da hidrotalcita, o que representa uma economia de energia durante as sínteses dos catalisadores, uma vez que esta etapa é a mais dispendiosa, em termos energéticos. Para melhorar o processo e reduzir a formação de coque, oxigênio foi adicionado como ar sintético à corrente dos reagentes, numa reação conhecida como Reforma Oxidativa do Biogás. Aqui, a proporção H2/CO foi próxima a 1, ao longo da faixa de temperatura considerada durante os testes catalíticos, associada à ocorrência da reação de oxidação parcial do metano, especialmente a temperaturas mais baixas. Como tentativa de aprimorar a gasificação do coque durante as reações de reforma, o elemento cério também foi adicionado durante a síntese das hidrotalcitas, também por coprecipitação, fixando a quantidade de cério e variando o teor de níquel, eliminando a etapa de envelhecimento. Neste ponto, os catalisadores não promovidos e promovidos com cério foram comparados através da reforma direta do biogás, em testes de estabilidade com duração de 6 horas, a 650oC. Após o uso, os catalisadores foram caracterizados por análise termogravimétrica a fim de avaliar a quantidade de carbono formado. Para os catalisadores derivados dos óxidos correspondentes a 5 e 15% de níquel (% nominal, em massa), foi encontrada maior deposição de carbono na presença dos catalisadores promovidos, embora para o primeiro, o pico de temperatura referente à remoção de carbono tenha sido menor comparado ao do catalisador não promovido. Ao contrário, para os catalisadores correspondentes a 10 e 25% de níquel (% nominal, em massa), similar e menor formação de carbono foram encontrados na presença de cério, respectivamente. Durante os ensaios de estabilidade de reforma oxidativa, foi possível constatar a redução da quantidade de carbono formado após os ensaios catalíticos.

The use of carbon from fossil-based resources result in changes in the earth’s climate due to emissions of greenhouse gases. Biomass is the only renewable source of carbon that may be converted to transportation fuels and chemicals, markets now fully dominated by traditional oil supply. The biorefinery concept for upgrading and refinement of biomass feedstocks to value-added end-products has the potential to mitigate greenhouse gas emissions and replace fossil products. Most biorefineries use biochemical conversion processes and may have by-product streams suitable as feedstocks for thermal conversion and production of syngas. Further synthesis to value-added products from the syngas could increase the product output from the biorefinery. The application of thermal conversion processes integrated into an existing biorefinery concept has been evaluated in this licentiate thesis work. Two by-product streams; hydrolysis (lignin) residue from an ethanol plant and biogas from wastewater treatment, have been investigated as gasification/reforming feedstocks. Also, the pre-treatment method torrefaction has been evaluated for improved gasification fuel characteristics and integration aspects. A new process and system concept (Bio2Fuels) with potential carbon negative benefits has been suggested and evaluated as an alternative route for syngas production by separating biomass into a hydrogen rich gas and a carbon rich char product. The evaluation demonstrated that hydrolysis residue proved a suitable feedstock for gasification with respect to syngas composition. Biogas can be further reformed to syngas by combined biomass gasification and methane reforming, with promising results on CH4 conversion rate and increased H2/CO ratio at temperatures ≥1000°C. The pre-treatment method torrefaction was demonstrated to improve fuel qualities and may thus significantly facilitate entrained flow gasification of biomass residue streams. Also, integration of a torrefaction plant at a biorefinery site could make use of excess heat for drying the raw material before torrefaction. The Bio2Fuels concept was evaluated and found feasible for further studies. The application of thermal conversion processes into an existing biorefinery, making use of by-products and biomass residues as feedstocks, has significant potential for energy integration, increased product output as well as for climate change mitigation.

A velocidade de queima laminar adiabática é um importante parâmetro da combustão que dita o comportamento de chamas pré-misturadas. Dos métodos disponíveis para a medição desse parâmetro, o método do fluxo de calor destaca-se pela simplicidade e precisão. No presente trabalho, esse método é utilizado para medir a velocidade de queima de biogás (modelado como CH4 com diferentes níveis de diluição com CO2) e de gás de síntese (modelado como uma mistura de CH4, H2, CO, CO2 e N2) em ar a 298 K e 1 atm. Tais gases são de crescente interesse para a sociedade em função de aspectos ambientais, porém, suas velocidades de queima não foram amplamente estudadas ainda. Os resultados obtidos são comparados com as previsões de cinco mecanismos cinéticos (GRI-Mech 3.0, Davis et al., Konnov, San Diego e USC Mech II) a fim de avaliar a sua capacidade preditiva. Os resultados experimentais e numéricos das velocidades de queima de biogás e ar apresentam uma boa concordância e as incertezas encontradas foram condizentes com as relatadas na literatura. Os resultados experimentais desse gás foram parametrizados em uma correlação empírica de fácil utilização em modelos numéricos. As medições da velocidade de queima de gás de síntese e ar, por outro lado, apresentaram valores inferiores às previsões numéricas de todos os mecanismos estudados. Os dados experimentais da literatura, para a mesma mistura, diferem tanto em valores quanto em comportamento dos resultados do presente trabalho. Tal comportamento está provavelmente relacionado a alguma contaminação no CO utilizado, já que quando esse gás está presente observa-se uma chemi-luminescência não relatada na literatura. / The adiabatic laminar burning velocity is an important combustion parameter that dictates premixed flames characteristics. Among the measuring methods available in literature, the heat flux method stands out for its simplicity and accuracy. In the present work, this method is used to measure the adiabatic laminar burning velocity of biogas (modeled as CH4 with different dilution levels with CO2) and syngas (modeled as a CH4, H2, CO, CO2 and N2 mixture) in air at 298 K and 1 atm. Such gases are of growing society interest due to environmental aspects, however, their adiabatic laminar burning velocity have not been widely studied yet. The experimental results are compared to predictions of five kinetic mechanisms (GRI-Mech 3.0, Davis et al., Konnov, San Diego e USC Mech II) to evaluate their predictive capacity. Experimental and numerical results of biogas/air mixtures adiabatic laminar burning velocity show good agreement and the found uncertainties are in agreement with literature. Experimental results of this gas were fitted in an empiric correlation of simple numerical application. Experimental results of the laminar burning velocity of syngas/air, on the other hand, show lower values than the numerical predictions of all studied kinetic mechanisms. Literature available data for the same mixture differ both in values and behavior of the present work results. Such behavior is probably related to some contamination on the CO used since a chemi-luminescence not reported in literature can be noted when this gas is present.

A velocidade de queima laminar adiabática é um importante parâmetro da combustão que dita o comportamento de chamas pré-misturadas. Dos métodos disponíveis para a medição desse parâmetro, o método do fluxo de calor destaca-se pela simplicidade e precisão. No presente trabalho, esse método é utilizado para medir a velocidade de queima de biogás (modelado como CH4 com diferentes níveis de diluição com CO2) e de gás de síntese (modelado como uma mistura de CH4, H2, CO, CO2 e N2) em ar a 298 K e 1 atm. Tais gases são de crescente interesse para a sociedade em função de aspectos ambientais, porém, suas velocidades de queima não foram amplamente estudadas ainda. Os resultados obtidos são comparados com as previsões de cinco mecanismos cinéticos (GRI-Mech 3.0, Davis et al., Konnov, San Diego e USC Mech II) a fim de avaliar a sua capacidade preditiva. Os resultados experimentais e numéricos das velocidades de queima de biogás e ar apresentam uma boa concordância e as incertezas encontradas foram condizentes com as relatadas na literatura. Os resultados experimentais desse gás foram parametrizados em uma correlação empírica de fácil utilização em modelos numéricos. As medições da velocidade de queima de gás de síntese e ar, por outro lado, apresentaram valores inferiores às previsões numéricas de todos os mecanismos estudados. Os dados experimentais da literatura, para a mesma mistura, diferem tanto em valores quanto em comportamento dos resultados do presente trabalho. Tal comportamento está provavelmente relacionado a alguma contaminação no CO utilizado, já que quando esse gás está presente observa-se uma chemi-luminescência não relatada na literatura. / The adiabatic laminar burning velocity is an important combustion parameter that dictates premixed flames characteristics. Among the measuring methods available in literature, the heat flux method stands out for its simplicity and accuracy. In the present work, this method is used to measure the adiabatic laminar burning velocity of biogas (modeled as CH4 with different dilution levels with CO2) and syngas (modeled as a CH4, H2, CO, CO2 and N2 mixture) in air at 298 K and 1 atm. Such gases are of growing society interest due to environmental aspects, however, their adiabatic laminar burning velocity have not been widely studied yet. The experimental results are compared to predictions of five kinetic mechanisms (GRI-Mech 3.0, Davis et al., Konnov, San Diego e USC Mech II) to evaluate their predictive capacity. Experimental and numerical results of biogas/air mixtures adiabatic laminar burning velocity show good agreement and the found uncertainties are in agreement with literature. Experimental results of this gas were fitted in an empiric correlation of simple numerical application. Experimental results of the laminar burning velocity of syngas/air, on the other hand, show lower values than the numerical predictions of all studied kinetic mechanisms. Literature available data for the same mixture differ both in values and behavior of the present work results. Such behavior is probably related to some contamination on the CO used since a chemi-luminescence not reported in literature can be noted when this gas is present.

Catalisadores ativos e estáveis, preparados a partir dos hidróxidos duplos lamelares (HDLs) contendo os cátions Ni2+, Zn2+, Al3+ e Zr4+(NiZn-Al, NiZn-AlZr e NiZn-Zr), foram avaliados na reação de reforma seca do metano. Os precursores foram caracterizados por difração de raios X, confirmando a formação das fases para as amostras de NiZn-Al e NiZn-AlZr. As espectroscopias no infravermelho/Raman elucidaram a ocorrência dos ânions (CO32-) e das moléculas de água na intercamada. A Fisissorção de nitrogênio ( método de BET) determinou a presença de poros e a área superficial específica. As formas das isotermas foram do tipo IV, de acordo com a IUPAC, e representa uma estrutura mesoporosa. A análise termogravimétrica foi utilizada para determinar a temperatura de calcinação dos precursores para obtenção dos catalisadores e as temperaturas utilizadas foram 550 °C, 650 °C e 750 °C. Os resultados de difração de raios X dos catalisadores apresentaram uma mistura de óxidos binários (NiO, ZnO, ZrO2 e Al2O3) e óxidos ternários (NiAl2O4 e ZnAl2O4). As fases de espinélios foram observadas nos catalisadores obtidos a 650°C (Ni/ZnAl-6 e Ni/ZnAlZr-6) e 750°C (Ni/ZnAl-7 e Ni/ZnAlZr-7). A redução a temperatura programada de hidrogênio (TPR-H2) forneceu informações sobre a redução do catalisador. Os resultados exibiram interações entre a fase ativa com as outras fases presentes no intervalo entre 350 - 800 °C, enquanto que a dessorção àtemperatura programada de CO2 (DTP-CO2) mostrou que os catalisadores possuem sítios básicos fracos. Ademais, os catalisadores foram caracterizados por fisissorção de nitrogênio, microscopia eletrônica de varredura (MEV), espectroscopia Raman e basicidade usando um indicador de Hammett. O desempenho dos catalisadores foi avaliado na reação de reforma seca do metano utilizando uma razão molar de alimentação de CH4: CO2 = 1,5:1,0; a fim de simular a composição do biogás. Os resultados mostraram uma maior conversão para o CO2 em todos os catalisadores investigados, o que pode ser atribuído ao maior teor de CH4 alimentado. Além disso, é importante ressaltar a contribuição dos sítios básicos presentes nas amostras, o que pode também contribuir para a conversão do CO2. A maior conversão de CH4 foi observada para os catalisadores tratados a 750 °C. Após as reações, foi observada a formação de carbono grafite sobre todos os catalisadores, com menor percentual para a amostra Ni/ZnAl, calcinadas a 550 °C e 650 °C, e Ni/ZnZr-7, calcinada a 750 °C. Finalmente, os catalisadores calcinados a 650 °C e 750 °C também foram ativados na temperatura de 750°C e os resultados reacionais mostraram que essa temperatura favoreceu o processo de aglomeração e, portanto, promoveu baixas conversões para o CH4 e CO2. / Active and stable catalysts, prepared from the lamellar double hydroxides (HDLs) containing the cations Ni2 +, Zn2 +, Al3 + and Zr4 + (NiZn-Al, NiZn-AlZr and NiZn-Zr) were evaluated in the dry reforming reaction of methane. The precursors were characterized by X-ray diffraction method, confirming the formation of phases for NiZn-Al and NiZn-AlZr samples. Infrared / Raman spectroscopies elucidated the occurrence of anions (CO32-) and water molecules in the interlayer. Nitrogen physisorption (BET method) determined the presence of pores and the specific surface area. The shape of the isotherms were type IV, according to the IUPAC, representing a mesoporous structure. The thermogravimetric analysis was used to determine the calcination temperature of the precursors to obtain the catalysts and the temperatures used were 550 ° C, 650 ° C and 750 ° C. The X-ray diffraction results of the catalysts showed a mixture of binary oxides (NiO, ZnO, ZrO2 and Al2O3) and ternary oxides (NiAl2O4 and ZnAl2O4). The spinel phases were observed in the catalysts obtained at 650 °C (Ni/ZnAl-6 and Ni/ZnAlZr-6) and 750°C (Ni/ZnAl-7 and Ni/ZnAlZr-7) Temperature- programmed reduction with hydrogen (H2-TPR) provided information on catalyst reduction. The results showed interactions between the active phase and the other phases present in the range of 350 - 800 ° C, while temperature- programmed desorption of CO2 (CO2-TPD) showed that the catalysts have weak basic sites. In addition, the catalysts were characterized by Nitrogen physisorption, scanning electron microscopy (SEM), Raman spectroscopy and basicity using a Hammett indicator. The performance of the catalysts was evaluated in the dry reforming reaction of the methane using a CH4: CO2 molar feed ratio = 1.5: 1.0; In order to simulate the biogas composition. The results showed a higher conversion to CO2 in all the catalysts investigated, which can be attributed to the higher content of CH4 fed. In addition, it is important to restate the contribution of the basic sites present in the samples, which may also contribute to the conversion of CO2.The higher conversion of CH4 was observed for the catalysts treated at 750 ° C. After the reactions, the formation of graphite carbon was observed on all the catalysts, with a lower percentage for Ni / ZnAl samples, calcined at 550 ° C and 650 ° C, and Ni / ZnZr-7, calcined at 750 ° C. Finally, the catalysts calcined at 650 ° C and 750 ° C were also activated at the temperature of 750 ° C. and the reaction results showed that this temperature favored the agglomeration process and, therefore, promoted low conversions for CH4 and CO2.

Les procédés XTL de production de carburants de synthèse basés sur la réactionFischer-Tropsch ainsi que les centrales IGCC représentent des alternatives attractives à la productiond'énergie future. Ces deux technologies mettent en oeuvre des gaz de synthèse contenant des impuretésdont H2S. Afin de protéger les unités de la corrosion et les catalyseurs Fischer-Tropsch del'empoisonnement, il est nécessaire de désulfurer ce gaz à l'aide d'oxydes métalliques, tel que ZnO, qui sesulfurent de façon quasi irréversible. Cette étape peut engendrer de larges quantités de déchets solides.La régénération in-situ par voie oxydante des matériaux sulfurés a pour but de permettre le retour à laphase oxyde puis à sa réutilisation. C’est une voie prometteuse vers un procédé plus efficient. Cependantla formation de sulfates réfractaires durant la régénération impose une importante élévation de latempérature afin de pouvoir les décomposer. La recherche de solution conduisant à un abaissement de latempérature de régénération est donc nécessaire. Dans ce travail, nous nous sommes proposés d'étudierles phénomènes physico-chimiques mis en jeu lors de la sulfuration et de la régénération d'oxydessimples et composés. Les oxydes simples étudiés ont été sélectionnés à la suite d’une étudethermodynamique puis expérimentale. L’identification des réactivités singulières de ZnO et MoO3 aconduit à la formulation d’oxydes composés. En particulier, l’oxyde mixte ZnMoO4 est régénérable dès500°C. Des caractérisations in-situ ont mis en évidence les rôles de la texture du solide sulfuré et desphases contenant du molybdène dans le processus de régénération. Enfin, une étude réalisée avec unsolide mis et forme et sur banc de perçage a permis d’aboutir à l’élaboration de règles de design dusolide. / Metal oxide based materials are commonly used for the final desulphurization of syngas in IGCC andFisher-Tropsch based XTL processes. The formation of large amount of solid waste is a major issue forthis process. The in-situ oxidative regeneration is a promising way to avoid the waste formation and toenhance process efficiency. However, the formation of refractory metal sulphates during the regenerationprocess requires an increase of the regeneration temperature, in order to decompose the species and toallow the sorbent regeneration. In this work, we have studied the use of composed metal oxides todecrease the regeneration temperature, and the related physic-chemical phenomena involved.Thermochemical and experimental studies on various single oxides outlined the specific reactivity ofZnO and MoO3 phases. Consequently a more thorough study on ZnO and MoO3 composed metal oxideswas performed. In particular, it was shown that ZnMoO4, zinc molybdate phase can be regenerated attemperature as low as 500°C. This low regeneration temperature was explained by the sulphided solidtexture and the oxidation of the molybdenum species. Finally a shaped ZnMoO4 was synthesized andtexted on a lab-scale breakthrough experimental device to validate the concept and give guideline for thedesign of industrial regenerable sorbent.

A low-emissions power generator comprising a solid oxide fuel cell coupled to a gas turbine has been developed by Rolls-Royce Fuel Cell Systems. As part of the cycle, a fraction of the unreacted fuel (the off-gas) and oxidizer streams is reacted in a burner, which is the main source of pollutant formation. In this thesis a computational model of the burner has been developed which captures the formation of NOx and the oxidation of CO. This model gives accurate predictions at low computational cost, making it suitable for use as a design tool in future burner design optimization through parametric studies. A key factor in increasing computational efficiency was the development of a reduced H2/CO/N2 kinetic mechanism; from a starting mechanism of 30 species to 10 and 116 reactions to 6. The results of laminar opposed-flow diffusion flames have been used to validate the reduced mechanism. Several different turbulent combustion models have been evaluated by creating an interface between the reduced kinetic mechanism and the commercial CFD solver FLUENT. Comparison of model predictions with well-characterized turbulent syngas flames, which share a similar fuel composition to the experimental work conducted on the off-gas burner, shows acceptable agreement. These studies have demonstrated the sensitivity of modelling constants. Improved predictions were achieved by calibrating these constants and including radiative heat losses. Following suitable modification to reflect the predominantly laminar flow present in the current burner design, the relevant modelling approaches were applied to the off-gas burner. Comparison was made to previous detailed measurements, showing that the important trends of NOx and CO are captured in general. The model was extended to high pressure conditions, similar to those in the actual off-gas burner, with the emissions predictions within design limits. The outcome of this work is a fast, accurate design tool for CFD which has capabilities to simulate beyond the laminar burner studied here. It may be applied to more general types of off-gas/syngas burners where turbulence-chemistry interaction is expected to be more significant.

Orientador: Reginaldo Guirardello / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-18T13:21:06Z (GMT). No. of bitstreams: 1 Yamada_ShinobuTomas_D.pdf: 3876142 bytes, checksum: 951723c2abec9e70853595542ea18fe3 (MD5) Previous issue date: 2011 / Resumo: Esta tese apresenta a cinética e a fluidodinâmica do processo Fischer Tropsch realizado nos softwares científicos Fortran (Formula Translation) e CFX (Fluidodinâmica Computacional) da AEA Technology plc. O presente trabalho é uma simulação computacional de um sistema catalítico, multifásico, multicomponente e não isotérmico com topologia tridimensional, baseado em catalisador de cobalto suportado, recheio de esferas de aço e meio reacional formado por pseudocomponentes, gás combustível - GLP, nafta - gasolina - diesel, ceras de baixo - médio - alto peso molecular e vapor de água, além do gás de síntese (CO + H2) não convertido. As modelagens da cinética de reação e do balanço de massa estão estruturadas na linguagem de programação Fortran com modelos matemáticos da tecnologia Fischer Tropsch e as modelagens dos balanços de energia, momento e turbulência pelo software computacional CFX, com geometria baseada no Reator Arge Sasol em Leito Fixo composto por cinco domínios (recheio - meio reacional - entrada - saída - parede) e um subdomínio (catalisador), configuradas numa malha com mais de cinco milhões de elementos e um milhão de nós. A cinética é o modelo esquematizado por Sarup-Wojciechowski (1989) com a constante cinética definida pela expressão modificada da lei de Arrhenius. A modelagem da fluidodinâmica é tratada pelas equações de Navier Stokes e turbulência através do modelo k-? e "disperse phase zero equation", complementados pela biblioteca de propriedades fisico-químicas Diadem DIPPR, artigos científicos e experimentos em planta piloto realizados na Unidade de Industrialização do Xisto - Petrobras, São Mateus do Sul - (PR) / Abstract: This thesis presents the fluid dynamics and the kinetics of Fischer Tropsch Process in a fixed bed reactor accomplished in the scientific software Fortran (Formula Translation) and CFX (Computational Fluid Dynamics) of AEA Technology plc. The current work is a computational simulation of the catalytic system, multiphase, multicomponent and non isothermal with 3D topology, that is based on the cobalt supported catalyst, column random packing and the reaction mean treated on pseudo components concept, fuel gas - PLG, naphtha - gasoline - diesel oil, low - medium - high molecular weight waxes and water steam, besides non converted syngas (CO + H2). The kinetics reaction modelling and mass balance are structured in Fortran programming language with mathematic models of Fischer Tropsch technology. Also the energy balance, momentum and turbulence phenomena are structured by CFX, with geometry based on the Arge Sasol Fixed Bed Reactor consisted for five domains (packing - reaction media - in- out - wall) and one subdomain (catalyst), configured in a mesh with more than five million of elements and one million of nodes. The kinetic models are schematized by Sarup-Wojciechowski (1989) equation and the kinetic constant defined according to a modified expression of the Arrhenius law. The modelling of the fluid dinamics are considered on the Navier Stokes fundamental equations and turbulence phenomena through k-? and "disperse phase zero equation", complemented by the physical-chemicals library property Diadem DIPPR, scientifc articles and data referred to pilot plant experiments performed in the Unidade de Industrialização do Xisto - Petrobras, located in São Mateus do Sul - (PR) / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

As the largest source of iron in North America, and as the largest energy consumer in the modern integrated steel mill, the blast furnace is a critical part of modern ironmaking. Any improvements that can be made to the efficiency or emissions of the blast furnace can have far reaching environmental impacts as the production of one ton of steel results in 1.85 tons of carbon dioxide emissions. Given the concerted push to reduce greenhouse emissions, novel technologies are needed to improve efficiency. In this study the injection of preheated natural gas, precombusted syngas from a variety of feedstocks, and hydrogen injection were all modeled using computational fluid dynamics, from the tuyere through the shaft of the furnace. The impacts of these various operational changes were evaluated using CFD calculated analogs for Raceway adiabatic flame temperature (RAFT), top gas temperature (TGT), and coke rate (CR). Results indicate that a reduction of 3% to 12% in CO2 emissions is possible through the implementation of these technologies, with each possessing distinct benefits and drawbacks for industrial implementation.