Energies 2021, 14, 6531. https://doi.org/10.3390/en14206531 www.mdpi.com/journal/energies Article Potential for the Integrated Production of Biojet Fuel in Swedish Plant Infrastructures Karin Ericsson Environmental and Energy Systems Studies, Lund University, Box 118, 221 00 Lund, Sweden; karin.ericsson@miljo.lth.se Abstract: Replacing fossil jet fuel with biojet fuel is an important step towards reducing greenhouse gas (GHG) emissions from aviation. To this end, Sweden has adopted a GHG mandate on jet fuel, complementing those on petrol and diesel. The GHG mandate on jet fuel requires a gradual reduc- tion in the fuel’s GHG emissions to up to 27% by 2030. This paper estimates the potential production of biojet fuel in Sweden for six integrated production pathways and analyzes what they entail with regard to net biomass input and the amount of hydrogen required for upgrading to fuel quality. Integrated production of biofuel intermediates from forestry residues and by-products at combined heat and power plants as well as at the forest industry, followed by upgrading to biojet fuel and other transportation fuels at a petroleum refinery, was assumed in all the pathways. The potential output of bio-based transportation fuels was estimated to 90 PJ/y, including 22 PJ/y of biojet fuel. The results indicate that it will be possible to meet the Swedish GHG mandate for jet fuel for 2030, although it will be difficult to simultaneously achieve the GHG mandates for road transportation fuels. This highlights the importance of pursuing complementary strategies for bio-based fuels. Keywords: biojet fuel; sustainable aviation fuel; drop-in biofuels; integration; plant infrastructure; Sweden 1. Introduction Carbon dioxide (CO2) emissions from aviation have grown steadily over the past decades and in 2019, they amounted to nearly 1 Gt CO2 globally [1]. This corresponds to about 2–3% of global CO2 emissions [1]. Although levels have been reduced in 2020–2021 due to the COVID-19 pandemic, they are expected to increase again. Replacing fossil jet fuels with sustainable aviation fuels (SAF) will be important in reducing CO2 emissions from the aviation industry [2,3]. In the short and medium-term perspectives, such a fuel shift is generally assumed to require a drop-in fuel, i.e., a biojet or electrofuel, that has the same chemical and physical properties as fossil jet fuel and thus is compatible with exist- ing aircraft engines and fuel distribution systems [4]. Liquid hydrogen may serve as fuel in the long term, while electric aircrafts powered by batteries are mainly seen as an option for short-haul flights [5,6]. So far, the consumption of SAF is marginal, accounting for less than 0.1% of the global consumption of jet fuel [1], most of which is synthetic paraffinic kerosene from hydroprocessed esters and fatty acids (HEFA-SPK) [1]. To increase the use of SAF, the European commission has proposed imposing a blend-in mandate that obliges fuel suppliers to supply a minimum share of SAF to the airports in the EU [7]. Such a regulation is already in place in Norway and was recently introduced in Sweden. In Sweden, the regulation is designed as a GHG reduction man- date on all jet fuel sold in the country, thus taking the climate impact of SAF into account. The required emission reduction starts at 0.8% for 2021 and will gradually increase to 27% in 2030 [8]. Emissions will be calculated based on the life-cycle perspective in accordance with the guidelines in the EU Renewable Energy Directive. These guidelines stipulate that Citation: Ericsson, K. Potential for Integrated Production of Biojet Fuel in Swedish Plant Infrastructures. Energies 2021, 14, 6531. https://doi.org/10.3390/en14206531 Academic Editor: Constantine D. Rakopoulos Received: 8 September 2021 Accepted: 8 October 2021 Published: 12 October 2021 Publisher’s Note: MDPI stays neu- tral with regard to jurisdictional claims in published maps and institu- tional affiliations. Copyright: © 2021 by the authors. Li- censee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and con- ditions of the Creative Commons At- tribution (CC BY) license (http://crea- tivecommons.org/licenses/by/4.0/).