Rafael L Orozco, PhD thesis 2011 HYDROGEN PRODUCTION FROM BIOMASS BY INTEGRATING THERMO-CHEMICAL AND BIOLOGICAL PROCESSES Rafael Orozco-Pulido A thesis submitted to The University of Birmingham for the degree of DOCTOR OF PHILOSOPHY School of biosciences The University of Birmingham, UK I-1 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. Rafael L Orozco, PhD thesis Abstract The purpose of this research was to contribute to the development of H2 production technologies from biomass. The study integrated thermochemical processes to achieve biomass hydrolysis with biological methods to then obtain H2 by the fermentation of these hydrolysates using E. coli. Different strains of E. coli were tested under controlled conditions in 3 L scale fermentations with the aim to find the most useful strain for the fermentation process in terms of H2 produced and the subsequent hydrogen production potential of the organic acid co-products in a downstream photofermentation. Among the strains tested FTD89, FTD67 and RL009 gave the best results, however ethanol was successfully abolished by strain RL009 making this strain more suitable for long term fermentations. Model polysaccharide compounds such as starch and cellulose, and representative food and lignocellulosic wastes were hydrolysed in hot compressed water in the presence of CO2 under pressure and various temperatures to produce hydrolysates with high sugar content suitable for fermentation for H2 production. Optimum hydrolysis conditions for maximum sugar yields for each compound were determined. Fermentation of the obtained hydrolysates yielded acceptable amounts of H2 after their ‘detoxification’ with activated carbon (AC), comparable to H2 yielded by the glucose controls in all cases. The maximum yield of glucose after HCW treatment was obtained from starch at 200 °C yielding 548 g C.kg C initial starch-1; maximum glucose yield from cellulose was 225 g C.Kg C initial cellulose-1 obtained from cellulose hydrolysis at 250 °C, and the glucose yield from food waste was 45.5 g.g food waste-1. The main degradation product (DP) from these hydrolysates was 5 Hydroxymethylfurfural (5-HMF), whereas the main DP obtained from the lignocellulosic wastes was Furfural. Both were successfully removed by AC treatment. The best hydrolysate obtained from wastes was evaluated for H2 production at 3 L scale. Despite obtaining low H2 yields improvements would be possible and are discussed. Fermentations for H2 production at pilot plant scale were also trialled, indicating key areas for future development for successful scale up. i Rafael L Orozco, PhD thesis Dedicated to: God, To RocioϮ And, very specially to my wife Marycarmen and my children Rafael, Dulcemary and Fermin. ii Rafael L Orozco, PhD thesis Acknowledgements Very special thanks to my supervisor Professor Lynne E. Macaskie for all her invaluable support, patience, guidance and understanding throughout my PhD. To Professor Gary Leeke for all his help and collaboration and Professor Regina Santos. Also I appreciate and thank the invaluable help, collaboration and friendship of Dr. Mark D. Redwood at all times throughout my PhD. His support helped me to improve and add value to my PhD. Special thanks to all my lab mates who I owe a great debt: Dr. Kevin D. Planche, Dr. Claire Mennan, Dr. Ping Yong, Dr. Marion Petterson, Dr. Neil Crammer, Dr. Inina Mihkeenko, Miss Angela Murray for their collaboration, willingness and enthusiasm always available to help. All my colleagues from other departments and Universities who also provided help with valuable discussions and assistance: Dr. Ali Bahari, Mr. Ricardo Roque, Professor Xu-Zhang. Thanks to my parents for all their support at all times. Thanks to CONACYT for funding my throughout my study. Thanks to the University of Birmingham, staff and other institutions (BBSRC, EPSRC) for all their collaboration during my studies. And last but not least, to the Staff House and everyone who worked there during my PhD. This was the place where every Friday I met with friends to share great moments (and some pints) and to discuss important diverse topics, it became a meaningful part of my social life at the University. iii Rafael L Orozco, PhD thesis Statement I declare that this thesis contains no material which has been accepted for the award of any other degree or diploma in any University and that, to the best of my knowledge, this thesis contains no materials written by any person except where due reference is given in the text of this thesis. Rafael L Orozco iv Rafael L Orozco, PhD thesis Layout of the thesis Each chapter is presented in form of a scientific paper; beginning with an abstract/introduction which defines the focus of the chapter and present information relevant to the work, followed by a method and analysis section, a results and discussion section and conclusions. Additional methodology is described in the appendices. Participations in seminars, conferences and other relevant work is also in the appendix section. References were added at the end of the thesis. v Rafael L Orozco, PhD thesis TABLE OF CONTENTS I. INTRODUCTION ................................................................................................................................................... 1 I.1 CLIMATE CHANGE ......................................................................................................................................................... 1 I.2 WASTE DISPOSAL ......................................................................................................................................................... 4 I.3 ENERGY ..................................................................................................................................................................... 6 I.4 THE CHALLENGE, ACTIONS AND POLICIES. ....................................................................................................................... 11 I.5 TOWARDS THE HYDROGEN ECONOMY ............................................................................................................................. 14 II. HYDROGEN PRODUCTION TECHNOLOGIES......................................................................................................... 19 II.1 HYDROGEN FROM STEAM REFORMING OF METHANE ..................................................................................................... 19 II.2 HYDROGEN FROM WATER ELECTROLYSIS ..................................................................................................................... 21 II.3 HYDROGEN FROM BIOMASS UTILISATION .................................................................................................................... 23 II.3.1 Thermochemical processes........................................................................................................................... 28 II.4 BIOLOGICAL METHODS ............................................................................................................................................ 39 II.4.1 Biophotolysis of water .................................................................................................................................. 40 II.4.2 Photo fermentative processes. ..................................................................................................................... 41 II.4.3 Dark fermentation. ....................................................................................................................................... 43 II.4.4 Hybrid systems for H2 production ................................................................................................................. 50 III. BIOMASS HYDROLYSIS METHODS ...................................................................................................................... 56 IV. AIMS AND OBJECTIVES .................................................................................................................................. 62 V. LAYOUT OF THE THESIS ...................................................................................................................................... 64 VI. RESULTS AND DISCUSSIONS. .......................................................................................................................... 68 VI.1 E. COLI STRAIN EVALUATION FOR H2 PRODUCTION ........................................................................................................ 69 VI.1.1 E. coli strains evaluation for H2, OA and ethanol production ................................................................... 70 VI.1.2 Strains RL007 and RL009 in comparison to parent strain MC4100 .......................................................... 86 VI.1.3 Towards an integrated system for bio-energy ......................................................................................... 97 VI.2 HYDROGEN FROM STARCH ....................................................................................................................................