Evaluation of a Detailed Reaction Mechanism for Partial and Total Oxidation of C1 - C4 Alkanes

ACKNOWLEDGMENTS I would like to acknowledge to all the people who helped me directly or indirectly to accomplish this dissertation: First and foremost, I would like to express all my gratitude towards Prof. Dr. Dr. h. c. Jürgen Warnatz for giving the opportunity to share an unforgettable time in his group in Heidelberg. To Prof. Dr. Olaf Deutschmann and his family, for his support during my time in Heidelberg, for the useful comments and great support in the development of my work and for his friendship during difficult moments. To Farid Chejne, my former tutor in Colombia, for his tireless compromise with all of us, for being more than a tutor, a friend. I am also thankful to my colleagues at IWR: Ingrid for her collaboration with all the administrative details, to Barbara for her unvaluable help, to Jürgen Moldenhauer, Till Katzenmeier, Volker Karbach, Shaik and all my coworkers for their help and understanding. Finally, I would like to thank Sophia, for her boundless love, faith in me, and encouragement and for bring to my life the most beautiful thing that ever happen to me: Madeleine, without both of you this work would still not be completed. ii iii ABSTRACT In the present work a chemical kinetic mechanism was developed, suitable for modeling combustion and partial oxidation processes of C 1 – C 4 alkanes. The gas-phase kinetic mechanism describes intermediate and high temperature chemistry. Accordingly, the formation and evolution of important intermediate gas-phase species: Olefins and oxygenates were described in terms of different pathways typical at those temperature regimes. A previously developed mechanism suitable for high temperature conditions was extended by including reactions which described the chemistry of total and partial oxidation of methane, ethane, propane, butane, lower alkenes and formation and consumption of their characteristic organic hydro-peroxide radicals and cyclical compounds. The kinetic mechanism was validated by comparing calculated results of ignition delay times, against experimental data obtained in shock tubes, for various hydrocarbons and their mixtures, over a wide range of reaction conditions (temperature, pressure and mixture composition). Further, the kinetic mechanism was evaluated by comparing numerical simulations against experimentally obtained concentration profiles of the main gas-phase species, measured in jet stirred reactors for different hydrocarbons and their mixtures during partial oxidation. Next, the mechanism was applied to get a better understanding of the interactions between flow, mass transfer and homogeneous-heterogeneous chemistries during the catalytic partial oxidation …