Sustainable aviation fuel production via the methanol pathway: a technical review

Due to the compatibility towards today's aviation infrastructure, sustainable aviation fuels (SAF) are expected to contribute to a significant reduction of this sector's CO2 emissions. The methanol pathway represents a synthesis-based route for producing SAF that can utilize various feedstocks, including electrolytically produced H2 and atmospheric CO2 through a power-to-liquid (PtL) process, which can be implemented at large-scale. The process is considered advantageous compared to other routes, primarily in terms of yield and low levels of byproduct formation, and is projected to efficiently produce jet fuel (C8–C16). This review analyzes the state of science for the entire process chain consisting of methanol synthesis, methanol-to-olefin conversion, oligomerization, and hydrogenation. Here, special attention is drawn to the respective feedstocks, reaction systems, reactor design and process layouts to highlight technology-specific challenges to be considered. After individually reviewing the sub-processes, their interfaces are analyzed to derive research demands on the process side.