Global biorenewable development strategies for sustainable aviation fuel production

Over the coming years, the world is projected to witness an upsurge in “drop-in” aviation biofuel production as part of the renewable energy and bioeconomy developments. This paper presents a comprehensive review of the current status of biojet fuel development and uptake in global commercial aviation industry, including state-of-the-art certified technologies (i.e. Fischer-Tropsch (FT); hydroprocessed esters and fatty acids (HEFA); alcohol-to-jet (ATJ); and hydroprocessing of fermented sugars (HFS)); potential feedstock that can be deployed; a comparison of techno-economic and environmental performances of biojet fuel production routes; airlines’ commitment in promoting higher biofuel uptake; and global initiatives and policies. This review shows that the HEFA route using oil-based crops is best performing in terms of lowest production cost and greenhouse gas emissions, however it is in competition with the existing road transport biofuel market. Lignocellulosic biomass and waste feedstock should be promoted in view of replacing food/feed crops which have high indirect land use change emissions. Therefore, further improvement should be focused on FT, ATJ and HFS routes to enhance the cost effectiveness of biojet fuel production and promote commercialisation of these technologies. The selection of feedstock and technologies for SAF production should be justified based on production cost and environmental footprint, while avoiding competition with the existing road transport biofuel market. The shortcomings in the SAF policies such as blending mandate and multiplier in RED II should be addressed to reduce the negative impacts of feedstock competition between the road and aviation biofuel sectors and to meet the decarbonisation targets.