Cost calculations for three different approaches of biofuel production using biomass, electricity and CO2

Kurzfassung

To achieve the emission mitigation and decarbonization goals, future aviation requires alternative sustainable fuels. Synthetic paraffinic kerosene, generated by Fischer-Tropsch synthesis, is certified as a drop-in jet fuel up to 50 %. Potential fuel production routes are via conversion of biomass (Biomass-to-Liquid, BtL), the combination of renewable power and biomass (Power-and-Biomass-to-Liquid, PBtL) and the conversion of carbon dioxide with hydrogen from renewable power (Power-to-Liquid, PtL). In order to compare the three different production routes, an Aspen Plus® model is designed for each production path and techno-economically assessed for an assumed capacity of 11 Mg·h-1 fuel production (equals 90 Gg·a-1 plant capacity). Even though the BtL route allows the lowest net production costs, it has some drawbacks compared to PBtL and PtL. Especially the low H to C ratio of biomass leads to limited fuel yields in the BtL process. These yields can be increased by a factor of about 3 when conducting the PBtL process with the same biomass input instead of BtL. The highest X-to-Liquid efficiency based on power input and energy in feedstock is found for PBtL (51.4 %) followed by PtL (50.6 %) and BtL (36.3 %). For BtL 73 % of the introduced carbon is lost as CO2. The total investment costs are highest for BtL, followed by PBtL and PtL. The net production costs are in the reverse order. The cost analysis reveals total PBtL investment costs of 742 M€ and net production costs of around 3 €·kg-1 with an electricity price of 105 €·MWh-1. The costs for electrolyzer and gasifier represent the largest shares of the total capital costs. As the net production costs are dominated for the electricity costs, low electricity prices and high capacities are advantageous for PBtL, while high electricity and low biomass costs favor BtL concept.