Hybrid Biomass- and Electricity-Based Kerosene Production-A Techno-Economic Analysis

Substitution of fossil kerosene with sustainable aviation fuels (SAFs) is a key instrument for reducing greenhouse gas (GHG) emissions in the aviation industry and achieving the sector's climate targets. Today, purely biomass- or electricity-based SAF production pathways are discussed. However, combining both approaches offers potential advantages, especially in terms of carbon utilization and product maximization. Thus, the goal of this paper is to carry out a techno-economic analysis of two hybrid processes that combine both biomass- and electricity-based production processes and can thus directly utilize the CO2 off-gas that inevitably occurs in the biomass-based process. The investigated process pathways are characterized by the biogenic intermediates being ethanol and biogas. The respective pathways are analyzed and compared in terms of technical (carbon and energy efficiency) and economic (kerosene production costs) indicators based on steady-state process simulation. These investigations show that although the process using ethanol is more efficient in terms of carbon utilization, it has a higher specific energy requirement for the target product kerosene than the biogas-based process. In both processes, the carbon and energy efficiency are below 30%, partly due to the unused carbon and energy of the solid residue, which cannot be biochemically converted. Despite the differences in process technology, both processes can achieve approximately the same kerosene production costs of 2775 euro(2022)/t(Kero). The addition of the electricity-based process results in significantly increasing production costs resulting from the investments in electrolyzers and the cost of renewable electricity. However, carbon efficiency and product generation can be increased by 13% points in terms of total hydrocarbon production compared to those of a purely biomass-based production.