Sanna Hellstén RECOVERY OF BIOMASS-DERIVED VALUABLE COMPOUNDS USING CHROMATOGRAPHIC AND MEMBRANE SEPARATIONS Thesis for the degree of Doctor of Science (Technology) to be presented with due permission for public examination and criticism in the Auditorium 1383 at Lappeenranta University of Technology, Lappeenranta, Finland on the 12th of December, 2013, at noon. Acta Universitatis Lappeenrantaensis 556 Supervisors Professor Tuomo Sainio Faculty of Technology Department of Chemical Technology Lappeenranta University of Technology Finland Professor Mika Mänttäri Faculty of Technology Department of Chemical Technology Lappeenranta University of Technology Finland Reviewers Professor Alois Jungbauer Institute of Applied Microbiology University of Natural Resources and Life Sciences, Vienna Austria Professor Susana Luque Department of Chemical and Environmental Engineering University of Oviedo Spain Opponent Professor Malte Kaspereit Institute of Separation Science and Technology Friedrich-Alexander-Universität Erlangen-Nürnberg Germany Custos Professor Tuomo Sainio Faculty of Technology Department of Chemical Technology Lappeenranta University of Technology Finland ISBN 978-952-265-528-8 ISBN 978-952-265-529-5 (PDF) ISSN-L 1456-4491 ISSN 1456-4491 Lappeenrannan teknillinen yliopisto Yliopistopaino 2013 ABSTRACT Sanna Hellstén Recovery of biomass-derived valuable compounds using chromatographic and membrane separations Lappeenranta 2013 114 p. Acta Universitatis Lappeenrantaensis 556 Diss. Lappeenranta University of Technology ISBN 978-952-265-528-8, ISBN 978-952-265-529-5 (PDF), ISSN 1456-4491 Utilization of biomass-based raw materials for the production of chemicals and materials is gaining an increasing interest. Due to the complex nature of biomass, a major challenge in its refining is the development of efficient fractionation and purification processes. Preparative chromatography and membrane filtration are selective, energy-efficient separation techniques which offer a great potential for biorefinery applications. Both of these techniques have been widely studied. On the other hand, only few process concepts that combine the two methods have been presented in the literature. The aim of this thesis was to find the possible synergetic effects provided by combining chromatographic and membrane separations, with a particular interest in biorefinery separation processes. Such knowledge could be used in the development of new, more efficient separation processes for isolating valuable compounds from complex feed solutions that are typical for the biorefinery environment. Separation techniques can be combined in various ways, from simple sequential coupling arrangements to fully-integrated hybrid processes. In this work, different types of combined separation processes as well as conventional chromatographic separation processes were studied for separating small molecules such as sugars and acids from biomass hydrolysates and spent pulping liquors. The combination of chromatographic and membrane separation was found capable of recovering high-purity products from complex solutions. For example, hydroxy acids of black liquor were successfully recovered using a novel multistep process based on ultrafiltration and size-exclusion chromatography. Unlike any other separation process earlier suggested for this challenging separation task, the new process concept does not require acidification pre- treatment, and thus it could be more readily integrated into a pulp-mill biorefinery. In addition to the combined separation processes, steady-state recycling chromatography, which has earlier been studied for small-scale separations of high-value compounds only, was found a promising process alternative for biorefinery applications. In comparison to conventional batch chromatography, recycling chromatography provided higher product purity, increased the production rate and reduced the chemical consumption in the separation of monosaccharides from biomass hydrolysates. In addition, a significant further improvement in the process performance was obtained when a membrane filtration unit was integrated with recycling chromatography. In the light of the results of this work, separation processes based on combining membrane and chromatographic separations could be effectively applied for different biorefinery applications. The main challenge remains in the development of inexpensive separation materials which are resistant towards harsh process conditions and fouling. Keywords: preparative chromatography, membrane filtration, biorefinery, recycling chromatography, hydroxy acids UDC: 543.544:547.47:66.081.3:66.081.6:66.067.1 ACKNOWLEDGEMENTS This work has been carried out at Lappeenranta University of Technology in the Laboratory of Separation Technology during 2011–2013. Graduate School in Chemical Engineering (GSCE), FuBio Joint Research 2 programme of Finnish Bioeconomy Cluster (FIBIC), and LUT Centre for Separation Technology (CST) are acknowledged for funding. I wish to express my deepest gratitude to my supervisors, Prof. Tuomo Sainio and Prof. Mika Mänttäri. I highly appreciate their scientific expertise and enthusiasm, and the support and guidance they have kindly provided has been crucial for the completion of this work. Doc. Mari Kallioinen deserves also warm thanks for all her helpful advice and for the encouragement. In addition, I wish to acknowledge Prof. Marjatta Louhi-Kultanen for giving me the opportunity to start my doctoral studies. I am indebted to the pre-examiners of this thesis, Prof. Susana Luque and Prof. Alois Jungbauer, for their valuable comments that greatly helped to improve the thesis. I am much obliged to many of my colleagues who kindly provided their help during this work. First of all, I wish to thank Jani Siitonen, Jari Heinonen and Jussi Lahti for all the precious guidance and for the inspiring discussions. In addition, I thank all the following people who have been involved in carrying out the experiments and analyses: Mikko Tyster, Ilkka Suppula, Teemu Puustinen, Marisa Mäntylä, Tuomas Nevalainen, Liisa Puro, Helvi Turkia, Anne Hyrkkänen, and Jarkko Kuivanen. I am also thankful to Klaus Niemelä and Stella Rovio of VTT for the good collaboration. I wish to thank all my co-workers in the Laboratory of Separation Technology for creating a very nice working atmosphere. Special thanks go to Daria for sharing the office and for always cheering me up. I am deeply grateful to my parents who have been supportive throughout my studies. I also want to thank all my friends for their understanding and encouragement. Finally, the most enormous thanks belong to my husband, Mikko, for his extreme patience and continuous support. Lappeenranta, December 2013 Sanna Hellstn LIST OF PUBLICATIONS This thesis is based on the following peer-reviewed scientific journal articles, which are referred to in the text by the Roman numerals I-IV. I Hellstn, S., Sainio, T., Steady state recycling chromatography in acid–sugar separation on an ion-exchange resin, Sep. Sci. Technol., 47 (2012) 2358–2365. II Hellstn, S., Siitonen, J., Mänttäri, M., Sainio, T., Steady state recycling chromatography with an integrated solvent removal unit – Separation of glucose and galactose, J. Chromatogr. A, 1251 (2012) 122–133. III Hellstn, S., Heinonen, J., Sainio, T., Size-exclusion chromatographic separation of hydroxy acids and sodium hydroxide in spent pulping liquor, Sep. Purif. Technol., 118 (2013) 234–241. IV Hellstn, S., Lahti, J. Heinonen, J., Kallioinen, M., Mänttäri, M., Sainio, T., Purification process for recovering hydroxy acids from soda black liquor, Chem. Eng. Res. Des., in press, http://dx.doi.org/10.1016/j.cherd.2013.06.001. The author’s contribution in the publications I The author analysed the experimental data and conducted the numerical simulation study. The manuscript was written together with the co-author. II The author made the numerical simulation study. The manuscript was written together with the co-authors. III The author planned the laboratory experiments together with the co-authors, carried out the experiments and analysed the data. The capillary electrophoresis (CE) analyses were done by collaborators. The manuscript was written together with the co-authors. IV The author planned and carried out the experiments with the help of an assistant (except the UF experiments which were carried out by a co-author), analysed the data and wrote the manuscript together with the co-authors. The CE analyses were done by collaborators. Table of contents 1 Introduction ....................................................................................................................... 15 2 Objectives and structure of the work .................................................................................. 18 2.1 Aims and scope of the study ........................................................................................ 18 2.2 Outline ........................................................................................................................ 19 3 Preparative chromatography .............................................................................................. 21 3.1 Separation materials and mechanisms.......................................................................... 21 3.1.1 Adsorption ............................................................................................................ 22 3.1.2 Ion-exclusion .......................................................................................................