Kerosene production from power-based syngas – A technical comparison of the Fischer-Tropsch and methanol pathway
lStefan Bube, Nils Bullerdiek, Steffen Voß, Martin Kaltschmitt
Highlights
•Fischer-Tropsch pathway surpasses methanol pathway in total product efficiency.
•Methanol pathway yields highest kerosene-related carbon and energy efficiency.
•Methanol pathway shows thermodynamic advantages due to direct CO2 conversion.
•Chain growth probabilities above 90% favor Fischer-Tropsch pathway efficiencies.
•MTO olefin selectivity mainly determines efficiencies of the methanol pathway.
Abstract
To achieve long-term greenhouse gas (GHG) neutrality within the aviation sector, substituting fossil aviation fuels with Sustainable Aviation Fuels (SAF) derived from renewable energy sources is essential. Among the synthetic SAF options produced through Power-to-Liquid (PtL) processes, the Fischer-Tropsch (FT) and methanol pathway are of significant interest. However, to assess and compare these pathways, detailed technical process analyses are required to provide a sound basis for economic and environmental assessments. Thus, this research paper investigates and compares both SAF production pathways starting from power-derived syngas within an in-depth technical analysis, providing novel insights into overall process characteristics and efficiencies. Carbon and energy flows are derived from steady-state flowsheet simulations. A variation of technical parameters (FT pathway: FT chain growth probability and hydrocracking behavior, Methanol pathway: Dehydration olefin-selectivity and oligomerization product distribution) is carried out to assess impacts on carbon and energy efficiency, indicating uncertainties and parameter ranges for optimized kerosene production. The results show a very high carbon efficiency of the FT pathway (98 to 99%) regarding the total liquid products, while the carbon efficiency regarding kerosene lies between 60 and 77%. For the methanol pathway, a higher kerosene carbon efficiency can be achieved (60 to 90%); however, the total product efficiency (74 to 92%) is notably lower. The energy efficiencies of both pathways behave similarly to carbon efficiency, with the methanol pathway benefiting from thermodynamic advantages, leading to higher energy efficiency at equal carbon efficiency. Within the FT pathway, kerosene efficiency increases at high chain growth probabilities, while a high olefin-selectivity is crucial for efficient kerosene production within the methanol pathway. The analysis results provide comprehensive insights into the technical behavior of the overall processes which contributes to an improved understanding of the production pathways.
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https://www.sciencedirect.com/scienc...16236124004162