From food waste to kerosene: combined bio- and thermochemical processing via the intermediate product 2,3-BDO – a technical analysis

In aviation, the most promising strategy for reducing greenhouse gas emissions is the use of sustainable aviation fuels (SAF). Biomass being a key feedstock poses specific challenges due to its limited availability and heterogeneous composition, highlighting the necessity for developing efficient and flexible conversion pathways for maximizing carbon and energy utilization. Given that integrated conversion pathways remain insufficiently explored, this study evaluates a novel, integrated process concept, utilizing food waste as the primary feedstock and combining biochemical conversion (consisting of dark fermentation, a microbial electrolysis cell and aerobic fermentation) with hydrothermal gasification to produce the intermediate 2,3-butanediol (2,3-BDO), followed by thermochemical conversion of 2,3-BDO to SAF. The overall process is modelled and simulated in Aspen Plus and evaluated in terms of overall carbon and energy efficiencies, supplemented by a sensitivity analysis of uncertain key parameters. The results show that the proposed pathway converts food waste into hydrocarbons with an overall carbon efficiency of 25.4% and an energy efficiency of 20.5%, of which 9.5% of the carbon and 7.6% of the energy are recovered as SAF. Additionally, the study identifies key parameters and strategies for potential process improvement, providing a quantitative basis for further process development.