The potential of lignin as a maritime biofuel Patrick Häggblom Master’s Thesis Supervisor: Docent Frank Pettersson Laboratory of Process and Systems Engineering Faculty of Science and Engineering Åbo Akademi University May 2021 Patrick Häggblom Master’s Thesis ___________________________________________________________________________ ACKNOWLEDGEMENTS First and foremost, I would like to thank the companies Elomatic Oy and Auramarine Oy for choosing to invest their time and effort into this environmentally important project which has given me a chance to work towards a greener future. It is a highly valuable topic that could lead to a decrease in the use of fossil fuels and the emissions they generate at some point in the near future. A special thanks to Ted Bergman and Veikko Tuominen, my designated contact persons at Elomatic and Auramarine, respectively. I would also like to thank my supervisor at Åbo Akademi University, Docent Frank Pettersson, for supporting and guiding me through the process of writing this thesis. Everyone else who has contributed to this project in some way, with either their expertise, time, or raw materials for the experiments carried out as a part of it, also deserve a big acknowledgement and my utmost gratitude. Finally, I would like to thank my family and friends, especially my fiancée Christina, who have been understanding and supportive during these challenging times in the middle of the COVID-19 pandemic in which this project was carried out. II Patrick Häggblom Master’s Thesis ___________________________________________________________________________ ABSTRACT In the 1940s, efforts towards lignin valorisation were triggered by high oil prices, but today, the motives are much more varied. The movement towards a greener future to combat climate change and the expected introduction of an emission-based fee have all surged interest towards renewable fuels – a topic that has been at the core of this entire study. This research project delves into different pathways that currently exist of utilising lignin as a maritime biofuel. In particular, lignin extracted from the Kraft pulping process, with a gross heating value measured at 27 MJ kg-1 and a potential worldwide production capacity estimated at 78 million tonnes per year, is considered to be the source that could make the biggest difference on the fuel market as of now. The challenge lies in both the isolation of the lignin from its feedstock and producing a viable fuel from it – one that can be cost-competitive with the marine fossil fuels currently in use. Several experiments (e.g., bomb calorimetry and elemental analysis) were carried out at a laboratory of Åbo Akademi University, and various approaches to create a lignin fuel were trialed in accordance with the equipment available. The results provided a ground for parameters used in a sensitivity analysis, where variables such as production costs and raw material prices were evaluated against a possible introduction of the EU emissions trading system, or an equivalent, also in the marine sector. While the production methods found need to be further assessed to provide a deeper understanding of the chemistry and the techno-economics behind them, the results obtained indicate that the cost of an emissions allowance unit would have to be 160 to 190 euros per CO2 equivalent for a lignin-methanol fuel produced to be directly competitive with the widely used marine fuel IFO 380. Keywords: lignin, biofuels, Kraft process, marine diesel engine III Patrick Häggblom Master’s Thesis ___________________________________________________________________________ ABBREVATIONS admt Air-dried metric ton ECA Emissions Control Area EJ Exajoule, 1018 Joule, unit of energy ETS Emissions Trading System EUA EU Allowance, emission credits used in the EU Emissions Trading System FAME Fatty acid methyl esters HFO Heavy fuel oil HHV Higher heating value HLB Hydrophilic-lipophilic balance HWE Hot water extraction IFO Intermediate fuel oil IMO International Maritime Organization ISO International Organization of Standardization kDa Kilodalton, unit of mass LHV Lower heating value LNG Liquified natural gas LSMGO Low-sulphur marine gas oil MDO Marine diesel oil MGO Marine gas oil MSDS Material safety data sheet Mw Molecular weight PDI Polydispersity index RED Relative energy difference ULSFO Ultra-low-sulphur fuel oil VLSFO Very-low-sulphur fuel oil IV Patrick Häggblom Master’s Thesis ___________________________________________________________________________ Types of technical lignins AFEX Ammonia fibre expansion lignin HL Hydrolysis lignin KL Kraft lignin LS Lignosulphonates OL Organosolv lignin SEL Steam-explosion lignin SL Soda lignin V Patrick Häggblom Master’s Thesis ___________________________________________________________________________ TABLE OF CONTENTS ACKNOWLEDGEMENTS .................................................................................................... II ABSTRACT ........................................................................................................................... III ABBREVATIONS .................................................................................................................. IV TABLE OF CONTENTS ...................................................................................................... VI 1 INTRODUCTION ........................................................................................................... 1 2 BACKGROUND ............................................................................................................. 3 2.1 Pulping processes ................................................................................................. 3 2.1.1 Kraft process .................................................................................................. 4 2.1.2 Sulphite process ............................................................................................ 8 2.1.3 Mechanical pulping...................................................................................... 13 2.1.4 Soda process ............................................................................................... 13 2.1.5 Organosolv process .................................................................................... 14 2.1.6 Other processes .......................................................................................... 15 2.2 Lignin types and their recovery ......................................................................... 16 2.2.1 Kraft lignin ..................................................................................................... 18 2.2.2 Lignosulphonates ........................................................................................ 23 2.2.3 Soda lignin .................................................................................................... 24 2.2.4 Organosolv lignin ......................................................................................... 24 2.2.5 Other lignin types ......................................................................................... 25 2.2.6 Summary and market outlook .................................................................... 26 2.3 Marine fuel industry ............................................................................................. 28 2.3.1 Regulations and guidelines ........................................................................ 28 2.3.2 Current fuel alternatives ............................................................................. 29 2.3.3 Future of marine fuels ................................................................................. 32 3 LIGNIN FUEL PRODUCTION PROCESSES ......................................................... 34 VI Patrick Häggblom Master’s Thesis ___________________________________________________________________________ 3.1 Solvolysis .............................................................................................................. 35 3.2 Pyrolysis ................................................................................................................ 38 3.3 Gasification ........................................................................................................... 41 3.4 Dispersion of ground lignin ................................................................................ 42 3.5 Lignin separation-hydrotreatment ..................................................................... 43 4 MATERIALS AND METHODS .................................................................................. 45 4.1 Materials ............................................................................................................... 45 4.1.1 Technical lignins .......................................................................................... 45 4.1.2 Marine fuels .................................................................................................. 49 4.1.3 Solvents ........................................................................................................ 51 4.1.4 Surfactants ................................................................................................... 51 4.2 Methods ................................................................................................................ 51 4.2.1 Elemental analysis ...................................................................................... 51 4.2.2 Bomb calorimetry ........................................................................................