ADVANCING TOWARDS BIOMASS-DERIVED SYNGAS FERMENTATION EVALUATION OF PROCESS PARAMETERS AND GAS COMPOSITION EFFECTS Zur Erlangung des akademischen Grades einer DOKTORIN DER INGENIEURWISSENSCHAFTEN (DR.-ING.) von der KIT-Fakultät für Chemieingenieurwesen und Verfahrenstechnik des Karlsruher Instituts für Technologie (KIT) genehmigte DISSERTATION von M. Sc Alba Infantes-López aus Mataró (Barcelona), Spain Tag der mündlichen Prüfung: 14.08.2020 Erstgutachter: Prof. Dr. Christoph Syldatk Zweitgutachter: Prof. Dr. Nicolaus Dahmen Zweitgutachterin: Dr. Anke Neumann This document is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0): https://creativecommons.org/licenses/by-sa/4.0/deed.en “Le rêve c’est tout – la technique, ça s’apprend.” Dreams are everything, technique can be learned. Jean Tinguely PREAMBLE Parts of this thesis have been published as peer reviewed research articles. They describe the main findings of my work. At the end of any applicable paragraph a reference note states the publication in which the content has been previously published. The text of these paragraphs is partially identical to the content of the publications. Layout, citation style, figures and formatting have been modified and adjusted to the style of this dissertation. Chapters that contain contents of previously published work are as follows: Chapters with the heading “General procedures for STR experiments”, “Impact of medium components and process parameters”, the discussion and the conclusion include content of the publication Infantes, A., Kugel, M., and Neumann, A. (2020). Evaluation of media components and process parameters in a sensitive and robust fed-batch syngas fermentation system with Clostridium ljungdahlii. Fermentation. 6(2), 61. DOI: 10.3390/fermentation6020061. Chapters with the heading “Evaluation of beech wood and lignin derived syngas”, the discussion and the conclusion include content of the submitted work for publication Liakakou, E. T., Infantes, A., Neumann, A., and Vreugdenhil, B. J. (2020). Connecting lignin gasification with syngas fermentation. Chapters with the heading “Impact of syngas composition and impurities”, the discussion and the conclusion include content of the publication Infantes, A., Kugel, M., Raffelt, K. and Neumann, A. (2020). Side-by-side comparison of clean and biomass-derived, impurity-containing syngas as substrate for acetogenic fermentation with Clostridium ljungdahlii. Fermentation. 6(3), 84. DOI: 10.3390/fermentation6030084. Chapters with the heading “Sequential cultivation for acetogenic fermentation from oxygen- containing waste gas” include content of the publication Mohr, T., Infantes, A., Biebinger, L., de Maayer, P., and Neumann, A. (2019). Acetogenic Fermentation From Oxygen Containing Waste Gas. Front. Bioeng. Biotechnol. 7, 433. DOI:10.3389/fbioe.2019.00433. I ACKNOWLEDGMENTS I would like to thank all those who have contributed towards the realization of this doctoral thesis. I especially, and sincerely thank Prof. Dr. Christoph Syldatk for giving me the opportunity to work and pursue my research at his group. To my supervisor Dr. Anke Neumann, thanks for the incredible support you have given me through my years at TeBi. Thanks for the constructive critics and ideas, and for the uncountable times we discussed together – you always helped me look at my results with a better light. I want to thank all students who worked with my and supported my research. You have all played a very important part on my thesis, and from each of you, I learned something. They are: Phillip Lemke, Nahla Isso and Laura Merker: thanks for your positivism and involvement; Karoline Haack and Laura Herrmann, a huge thank you to both for your commitment, organization and extremely professional approach to the experiments. Jennifer Reichert, thanks so much for helping with the analytics! Lars Biebinger, I thank the half of you I supervised for your contribution towards our shared paper! It was a pleasure working with you. To Lorenzo Wormer, I will be forever grateful for the amount of effort you put towards your Bachelor thesis. Thanks for your commitment, even when not everything went smooth. Last, but not least, Ana B. Torres Martínez: Santificado sea el Infors! Millones de gracias por estar ahí. Thanks for infusing good mood! And for our Mexican Spanish – European Spanish discussions, I will always remember this! To all my PhD colleagues at TeBi, past and present: You are truly the best people one could wish to be surrounded while pursuing a PhD. Special mention must be made to the members of our beloved Mädchenbüro: Olga, thanks for always listening when I needed someone to talk to. Rebecca, thanks for your authenticity! You never failed to make me smile! Caro, thanks for your valuable comments and advice, and for being my thesis mentor! Fei, you are a fountain of positivism! Also: Marcus, sin ti hubiera olvidado mi español. Gracias por estar siempre ahí! Stefan, Olli and Sascha: thanks for making me feel so welcome, and thanks for introducing me to TeBi and PhD student life! To the technicians team, past and present: Laura, Pascal, Delphine, Sandra, Elke and Daniela: thanks for taking care of the equipment, thanks for your support, and for teaching me. To Michaela: I could not have done this thesis without you. Thanks for the invaluable support, for making sure the fermenters were always in shape, for all your pieces of advice, and for answering all my questions. II Acknowledgments To Habibu, Katrin, Jens and Ulrike: I hugely appreciate the discussions we have had, and all your contributions during these years. Thanks for challenging my assumptions, and questioning my theories, you made a better scientist of me! To Beate and Susanne: thanks for being there, for always being ready to help and give advice, and for the nice conversations we have had. Finalment, he d’agrair a tots els de Mataró (i rodalies) per creure en mi, per aguantar-me durant aquests anys de doctorat, i per fer-me sentir sempre a casa: gràcies per ser-hi! Lluc: gràcies per acompanyar-me, sempre i en tot. Ets el pilar que m’ha sostingut tantes vegades. A mi familia: os lo debo todo. III LIST OF PUBLICATIONS Peer reviewed original research papers Mohr, T.*, Infantes, A. *, Biebinger, L., de Maayer, P., and Neumann, A. (2019). Acetogenic Fermentation From Oxygen Containing Waste Gas. Front. Bioeng. Biotechnol. 7, 433. DOI:10.3389/fbioe.2019.00433 *Co-first authorship Infantes, A., Kugel, M., and Neumann, A. (2020). Evaluation of media components and process parameters in a sensitive and robust fed-batch syngas fermentation system with Clostridium ljungdahlii. Fermentation. 6(2), 61. DOI: 10.3390/fermentation6020061 Infantes, A., Kugel, M., Raffelt, K., and Neumann, A. (2020). Side-by-side comparison of clean and biomass-derived, impurity-containing syngas as substrate for acetogenic fermentation with Clostridium ljungdahlii. Fermentation. 6(3), 84. DOI: 10.3390/fermentation6030084 Liakakou, E. T.*, Infantes, A.*, Neumann, A., Vreugdenhil, B. J., and Liakakou, E. T. Connecting lignin gasification with syngas fermentation. PREPRINT DOI: 10.31224/osf.io/9f5pj Submitted for publication (2020) *Co-first authorship Conference Talk Infantes, A., Neumann, A. (2019). Syngas Fermentation. EUBCE Workshop, Advanced biofuel production with energy system integration. EUBCE 2019, 27th European Biomass Conference & Exhibition Conference Posters Infantes A., Merker L., Reichart, J., Syldatk C. and Neumann A. Combining ABE and syngas fermentations for biobased fuels and chemicals. Annual Conference 2018 of the Association for General and Applied Microbiology (VAAM Jahrestagung) Infantes, A., Zwick, M., Stoll, I. K., Boukis, N., Oswald, F. and Neumann, A. Syngas Fermentation at Elevated Pressure. ProcessNet-Jahrestagung und 33. DECHEMA-Jahrestagung der Biotechnologen 2018. DOI: 10.1002/cite.201855330 IV List of publications Infantes A., Zwick M., Herrmann L., Torres A., Syldatk C. and Neumann A. Evaluation of “Impure” Syngas from the Karlsruhe Bioliq® Plant and Other Sources as Substrate in Syngas Fermentation. C1net Conference 4, 2019 Infantes, A., Wormer, L. and Neumann, A. Effect of CO or syngas overpressure on growth and product formation of Clostridium ljungdahlii. Annual Conference 2019 of the Association for General and Applied Microbiology (VAAM Jahrestagung) Infantes A., Kugel M., Neumann, A. Evaluation of “Impure” Syngas derived from Biomass Gasification as Substrate for Syngas Fermentation. Annual Conference 2020 of the Association for General and Applied Microbiology (VAAM Jahrestagung) V ABSTRACT The need for renewed efforts to transition from a petroleum-based economy towards a more bio-based economy is becoming ever more evident. If fossil resources continue to be the main source of fuel and bulk chemicals, it will become increasingly difficult to tackle problems such as climate change. In order to achieve a long-term sustainable development, renewable energy and biomass sources need to be the focus of research efforts. Biomass from renewable or waste sources can be gasified to generate syngas, which is mainly composed of H2, CO2 and CO. Impurities can be present, and will depend on the gasification technology used and the source of the biomass. Syngas, as well as CO-rich gases, can also be a by-product of industrial processes, like steel-mills. A highly specialized group of anerobic, autotrophic bacteria, known as acetogens, can use these gases as fermentation substrate. The syngas is metabolized