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Alternative fuels play a critical role in strategies aiming at the decarbonization of civil aviation. In this context, Power-to-Liquid fuels produced from renewable electricity, water and carbon dioxide represent a scalable and sustainable option [1]. An in-depth understanding of the entire process chain is key to identify the levers in future scale-up scenarios for PtL capacity deployment. This is not only true for the conversion and upgrading steps, but also extends to the green hydrogen and carbon dioxide feedstocks required. Direct capture from air (DAC) is a potential solution for sustainable CO2 provision at scale. It effectively closes the carbon cycle and enables decoupling the carbon source from fossil infrastructures and biomass. On the other hand, data availability is comparatively low, as DAC is a novel technology and only a small number of operational plants with a total annual output of around 10 t have been realized [2] orders of magnitude lower than what would be required in a net-zero emission scenario. Consequently, DAC, while representing a corner stone in the Power-to-Liquids process chain, is associated with considerable uncertainties when it comes to its potential for future widespread application. Several technology options based on solid or liquid sorbents exist, employing different temperature ranges and typically demanding both thermal and electrical energy. To deepen the understanding and illustrate the associated trade-offs, we employ future technology analysis and consolidate the results in a comparative multi-criteria assessment, taking into account energy demand, scalability, integrability, land requirements and future cost estimations, among other metrics. Further, we apply the learnings as an input to a thorough sensitivity study of the Power-to-Liquids production and supply chain, shedding light onto possible levers and bottlenecks. Finally, we draw a brief comparison to other fuel choices. References [1] Batteiger, V.; Ebner, K.; Habersetzer, A.; Moser, L.; Schmidt, P.; Weindorf, W.; Rakscha, T., Power-to-Liquids - A scalable and sustainable fuel supply perspective for aviation., German Environment Agency. (2022), available at: https://www.umweltbundesamt.de/en/publications [2] IEA, Direct Air Capture (2021), available at: https://www.iea.org/reports/direct-air-capture |
