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Orientador: Luiz Roberto Carrocci / Coorientador: Edgard Paz Perez / Banca: Celso Eduardo Tuna / Banca: Eliana Vieira Canettieri / Banca: Daniele Camargo Vernilli / Banca: Valesca Alves Corrêa / Resumo: A crescente demanda por energia aumenta a busca por fontes energéticas alternativas a fim de se desvencilhar daquelas não renováveis. Todavia, a decisão por uma fonte energética leva em conta fatores técnicos, econômicos, sociais, políticos e ambientais. O termo biodiesel aplica-se ao combustível substituto do óleo diesel, constituído de ésteres obtidos a partir de óleos vegetais, por processo de transesterificação com álcoois em meio ácido ou básico. A utilização de óleos vegetais como combustível apresenta vantagens, principalmente, quanto às emissões de gases nocivos. Contudo, apresenta desvantagens como elevada viscosidade e falta de volatilidade, e seu processo de obtenção gera resíduo não totalmente aproveitável. Sistemas microemulsionados aparecem como um tipo de combustível alternativo, pois se ampliam os limites advindos das propriedades de cada componente da mistura. Pode-se intervir na redução das emissões de poluentes e também em suas características. Permite a utilização de substâncias com menor valor econômico e reaproveitamento de resíduos, constituindo-se como substitutos para os derivados de petróleo, propiciando autossuficiência energética, fortalecimento do agronegócio, desenvolvimento regional sustentável, geração de emprego/renda e melhoria da qualidade do ar / Abstract: The growing demand for energy increases the search for alternatives to replace fossil sources by renewable energy sources. Nevertheless, the decision for an energy source shall consider technical factors, economic, social and environmental aspects as well. The term biodiesel refers to the substitute fuel for the original diesel, obtained from vegetable oil esters, by means of chemical transesterification with alcohols in acid or basic media. The use of vegetable oils as fuel presents many advantages, mainly concerning lower harmful gas emission. Although, they present disadvantages as high viscosity and lack of volatility, and their production process generates residues not completely usable. Micro-emulsion systems appear as alternatives because it is possible to take better advantage of the properties of each component of the system. It is possible to manipulate the system in order to reduce gas emissions and also their characteristics. It allows the use of components with lower economical value and recovery of residual products, becoming valuable substitutes for petrol derivatives, reducing external energy dependence, strengthen the agro-business, providing sustainable regional development, job and revenue generation and air quality improvement / Doutor

Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017. / One of the very promising synthetic fuel production strategies is the Fischer-Tropsch process, founded on the Fischer-Tropsch Synthesis, which owes its discovery to the namesake researchers Franz Fischer and Hans Tropsch. The Fischer-Tropsch Synthesis (FTS) converts via complex polymerisation reaction a mixture of CO and H2 over transition metal catalysts to a complex mixture of hydrocarbons and oxygen containing compounds with water as major by-product. The mixture of CO and H2 (termed syngas) may be obtained by partial oxidation of carbon containing base feedstocks such as coal, biomass or natural gas via gasification or reforming. The Fischer-Tropsch (FT) process thus presents the opportunity to convert carbon containing feedstocks to liquid fuels, chemicals or hydrocarbon waxes, which makes, for instance, the monetisation of stranded gas or associated gas a possibility. The FT-process is typically carried out in two modes of operation: low temperature Fischer-Tropsch (LTFT) and high temperature Fischer-Tropsch (HTFT). LTFT is normally operated at temperatures of 200 – 250 °C and pressures of 10 – 45 bar to target production of high molecular weight hydrocarbons, while HTFT is operated at 300 – 350 °C and 25 bar to target gasoline production. The catalytically active metals currently used commercially are iron and cobalt, since product selectivity over nickel is almost exclusively to methane and ruthenium is highly expensive in addition to requiring very high pressures to perform optimally. Fe is much cheaper, but tends to deactivate more rapidly than Co due to oxidation in the presence of high H2O partial pressures. One of the major drawbacks to using Fe as FT catalyst is the requirement of lower per pass conversion which necessitates tail gas recycle to extend catalyst life and attain acceptable overall conversions. A more active or similarly active but more stable Fe-catalyst would thus be advantageous. For this reason promotion of a self-prepared typical LTFT Fe-catalyst with Ru was investigated. A precipitated K-promoted Fe-catalyst was prepared by combination of co-precipitation and incipient wetness impregnation and a ruthenium containing catalyst prepared from this by impregnation with Ru3(CO)12. The catalysts, which had a target composition of 100 Fe/30 Al2O3/5 K and 100 Fe/30 Al2O3/5 K/3 Ru, were characterised using XRD, SEMEDX, ICP-OES, TPR and BET N2-physisorption, before testing at LTFT conditions of 250 °C and 20 bar in a continuously stirred slurry phase reactor.

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Antes de transportar os derivados de petróleo por dutos, a sua corrosividade é verificada por meio do ensaio NACE TM-0172 ?Determining Corrosive Properties of Cargoes in Petroleum Product Pipelines? (NACE, 2001). O referido ensaio, por basear-se na avaliação visual, não tem por objetivo a determinação da taxa de corrosão e nem a verificação do tipo de corrosão e, normalmente, os profissionais que o executam não têm conhecimento da influência das variáveis que interferem nos resultados do ensaio. Desta forma, o presente estudo teve como objetivos: verificar a influência de algumas variáveis (velocidade de agitação, geometria do corpo-deprova, temperatura, teor de água, tempo de ensaio e pH) nos resultados obtidos com o ensaio NACE TM-0172 (NACE, 2001), fazer avaliação quantitativa da taxa de corrosão por meio da determinação da perda de massa dos corpos-de-prova expostos ao meio, correlacionar os resultados da avaliação visual com a perda de massa, verificar se o ensaio, que é realizado em condições aeradas, simula adequadamente as condições internas dos dutos. Para condução do estudo, além do próprio ensaio NACE TM-0172 (NACE, 2001), foram realizados outros ensaios simples utilizando o aço-carbono COPANT 1020 na confecção dos corpos-de-prova metálicos. Com base em todos os ensaios realizados, foi possível fazer uma análise crítica do ensaio NACE TM-0172 (NACE, 2001) e justificar a adoção das diferentes condições de ensaio além de apresentar uma explicação para o mecanismo de corrosão do açocarbono na mistura derivado/água. / Before transporting distillate fuels by pipelines, their corrosive properties are verified by the NACE TM-0172 test ?Determining Corrosive Properties of Cargoes in Petroleum Product Pipelines? (NACE, 2001). This test, being based on a visual evaluation, has as its goal, neither the determination of the corrosion rate nor the verification of the corrosion type; the technicians usually do not know the influence of the variables that interfere in the test results. Thus, this study had as its goals: to verify the influence of some variables (stirring speed, coupon geometry, temperature, water content, test duration and pH of the water phase) in the results obtained with the NACE TM-0172 test (NACE, 2001), to make the quantitative evaluation of the corrosion rate by determination of the coupon mass loss exposed to this condition, to correlate the results of the visual evaluation with the mass loss, to verify if the test, which is made in aerated conditions, simulate properly the internal conditions of pipelines. To conduct the study, besides the NACE TM-0172 (NACE, 2001) test itself, other simple tests were made using the carbon steel COPANT 1020 to prepare the metallic coupons. Based on all the tests, it was possible to make a critical analysis of the NACE TM-0172 (NACE, 2001) test and (to) justify the adoption of different test conditions as well as there being the possibility of presenting an explanation for the mechanism of the carbon steel corrosion in the mixture distillate/water.

M.Phil. (Energy Studies) / South Africa has no commercially proven indigenous crude oil deposits. The country therefore follows a well formulated longterm energy policy to ensure a continuous and uninterrupted supply of transport fuels. The development of a very successful synfuel industry contributes to the national desire of maintaining a minimum level of self sufficiency in transport fuels. The Government also plays a supportive role in financing synthetic fuel projects from the Central Energy Fund. South Africa has abundant coal resources at a reasonable cost, as well as the offshore gas field near the coast of Mosselbay. The objective of this study is therefore to evaluate and compare the re1athe economics of certain direct and indirect coal liquefaction process routes, as well as the conversion of natural gas to transport fuels. The methanol option as a transport fuel is also addressed. Information for this study was collected mainly from the literature on this subject as well as Government institutions and private companies that are actively involved in the production of synthetic transport fuels. The primary conclusions of this study are: Synthetic fuel projects are capital intensive. The number of commercially proven options for the production of synfuels are limited to the well proven technology of the Sasol process, conventional methanol synthesis technology and to a lessor extent the Mobil methanol-to-gasoline technology. Accurate costs comparisons will therefore only be possible when more of the direct liquefaction options have been commercially demonstrated. Commercial realisat ion of the unproven technologies also involve enormous financial resources and a high risk. The Sasol synfuel option with the lowest thermal efficiency of approximately 42% requires the highest capital investment per ton or barrel of final product. The high severity direct processes (H-coal, Exxon-Donor-Solvent or EDS and the German Technology) as well as the Mobil-MTG capital investment follows, with the low severity and high thermal efficiency SRC-1 and SRC-2 process capital requirements the lowest, except for the very low,capital investment for a methanol synthesis plant...