Alternative fuels for Swedish short sea shipping and inland waterways: Techno-economic study

Abstract: Climate change is raising huge challenges for all industries worldwide. It is mainly due to anthropogenic activity and energy consumption which is the cause for emissions of greenhouse gas (GHG) among other environmental impacts and is expected to have huge impact on our societies globally. Of those global GHG emissions, around a quarter is emitted by transportations of all kinds as transportation relies heavily on fossil fuels. If the past years have seen a rising share of electrification within the passenger car industry, the commercial transportation isn’t that prone to electrification and other pathway to decarbonization are studied. Shipping is responsible for around 90% of the world commercial transportation work and therefore is a keyplayer in the transition toward low carbon transportation. It relies exclusively on fossil fuels with different kinds of oil-based fuels being the historical fuel suppliers and has seen a quick increase of the share of liquefied natural gas (LNG) in the past decade. Yet the international maritime organization (IMO) has set ambitious emission reduction targets for shipping and alternative fuel technologies are considered to be a relevant pathway if not the most promising pathway to low carbon or even zero carbon shipping. This study aims at evaluating and comparing different alternative fuels pathways available to perform the shift toward low carbon fuel technologies within Swedish short sea shipping (SSS) and inland waterway transportation (IWT) based on a set of criteria designed to reflect all aspects of the implementation of an alternative fuel pathway implementation. Those criteria are divided into 5 different categories which are technological, technical, economic, environmental, and finally social. There are 2 main categories to consider for low carbon fuels, biofuels and electrofuels. Fossil fuels are also included within the study so that the alternative pathways get compared not only with one another but also with the current marine fuels. The first comparison between different alternative fuel pathways is relevant to choose the most promising and feasible one while the comparison between a chosen alternative fuelpathway and the main marine fossil fuels is what stakeholders will look at when considering an alternativefuel pathway implementation challenge. The electrofuels included within the comparison are ammonia and hydrogen within 2 similar pathways which include production using water electrolysis and renewableelectricity (the carbon intensity of the Swedish grid is considered) before consumption within fuel cells (FC)instead of internal combustion engines (ICE). Those electrofuels end up with the last ranks within the comparison due to low technological maturity, technical and economic challenges remaining and social issued to address despite being the most environmentally promising pathways. Biofuel’s pathways on the other hand include both fischer tropsch diesel (FTD) and bio-methanol production using as feedstock various mixes of black liquor (BL) andpyrolysis oil (PO). FTD ends up as the most promising alternative fuel pathway within the whole studywhile bio-methanol appears more challenging but also more promising toward environmental criteria.