Deoxygenation of fatty acids for production of fuels and chemicals

The decreasing fossil fuel resources combined with an increasing world energy demand has raised an interest in renewable energy sources. The alternatives can be solar, wind and geothermal energies, but only biomass can be a substitute for the carbon–based feedstock, which is suitable for the production of transportation fuels and chemicals. However, a high oxygen content of the biomass creates challenges for the future chemical industry, forcing the development of new processes which allow a complete or selective oxygen removal without any significant carbon loss. Therefore, understanding and optimization of biomass deoxygenation processes are crucial for the future bio–based chemical industry. In this work, deoxygenation of fatty acids and their derivatives was studied over Pd/C and TiO2 supported noble metal catalysts (Pt, Pt–Re, Re and Ru) to obtain future fuel components. The 5 % Pd/C catalyst was investigated in semibatch and fixed bed reactors at 300 °C and 1.7–2 MPa of inert and hydrogen–containing atmospheres. Based on extensive kinetic studies, plausible reaction mechanisms and pathways were proposed. The influence of the unsaturation in the deoxygenation of model compounds and industrial feedstock – tall oil fatty acids – over a Pd/C catalyst was demonstrated. The optimization of the reaction conditions suppressed the formation of by–products, hence high yields and selectivities towards linear hydrocarbons and catalyst stability were achieved. Experiments in a fixed bed reactor filled with a 2 % Pd/C catalyst were performed with stearic acid as a model compound at different hydrogen–containing gas atmospheres to understand the catalyst stability under various conditions. Moreover, prolonged experiments were carried out with concentrated model compounds to reveal the catalyst deactivation. New materials were proposed for the selective deoxygenation process at lower temperatures (~200 °C) with a tunable selectivity to hydrodeoxygenation by using 4 % Pt/TiO2 or decarboxylation/decarbonylation over 4 % Ru/TiO2 catalysts. A new method for selective hydrogenation of fatty acids to fatty alcohols was demonstrated with a 4 % Re/TiO2 catalyst. A reaction pathway and mechanism for TiO2 supported metal catalysts was proposed and an optimization of the process conditions led to an increase in the formation of the desired products.

Theses miscellaneae (1757-07-27)

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Theses philosophicae (1759-06-27)

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Meditationes sancti evangelii 27

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Meditationes sanctarum epistolarum 27

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Theses (1824-11-27)

Painovuosi nimekkeestä.

Chronicon episcoporum Finlandensium 27

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In titulos libri 23-27 Corporis juris civilis Romani

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Dissfrtatio [!] philologica ... fidem Jobi ex cap. XIX:25, 26, 27. Considerans, qvam ex decrete celeberrimi consistorii Acad. Aboens. adprobante ampliss. facult. phil. publico bonorum examini sistit mag. Matthias Hallenius, facult. theol. adjunctus & pastor in Lundå, respondente Gabriele Tålpo, Aboensi, ad diem Deo volente, XXVII Julii, anni MDCCXLI. In auditorio maximo, horis ante meridiem solitis

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De signatura Filii Hominis: Deus, Joh. VI. v. 27

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Cognatio artis atq[ue] naturae, qvam dissertatione graduali, adfulgente gratia divina et ex amplissimi philos. ordinis suffragio, in Regia Academia Aboënsi, praeside ... dn. m. Torstano Rudeen, poës. prof. reg. ord. fac. phil. h. t. dec. spect. Ad d. 27 Martii anni 1697 in audit. max. hor. matut. consvetis publice examinandam exhibet Clemens Thelaus Hernösandensis

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