A solar tower fuel plant for the thermochemical production of kerosene from H ₂O and CO ₂

Summary

Developing solar technologies for producing carbon-neutral aviation fuels has become a global energy challenge, but their readiness level has largely been limited to laboratory-scale studies. Here, we report on the experimental demonstration of a fully integrated thermochemical production chain from H ₂O and CO ₂ to kerosene using concentrated solar energy in a solar tower configuration. The co-splitting of H ₂O and CO ₂ was performed via a ceria-based thermochemical redox cycle to produce a tailored mixture of H ₂ and CO (syngas) with full selectivity, which was further processed to kerosene. The 50-kW solar reactor consisted of a cavity-receiver containing a reticulated porous structure directly exposed to a mean solar flux concentration of 2,500 suns. A solar-to-syngas energy conversion efficiency of 4.1% was achieved without applying heat recovery. This solar tower fuel plant was operated with a setup relevant to industrial implementation, setting a technological milestone toward the production of sustainable aviation fuels.

Graphical abstract

Highlights

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  Entire process chain from H ₂O and CO ₂ to solar kerosene realized in a solar tower

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  50-kW solar reactor demonstrated for ceria-based thermochemical redox splitting

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  Consecutive redox cycling produced syngas suitable for FT synthesis

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  4.1% solar-to-syngas energy efficiency achieved without implementing heat recovery

Context & scale

The aviation sector, which strongly relies on fossil-derived kerosene, is responsible for vast amounts of anthropogenic greenhouse gas emissions. To avoid these emissions, solar energy can be leveraged to efficiently produce sustainable drop-in fuels, e.g., solar--made synthetic kerosene, which is fully compatible with the existing global jet fuel infrastructures for its storage, distribution, and end-use in jet engines. This work advances the technological readiness level of solar fuels production by demonstrating the technical feasibility of the entire sun-to-liquid fuel process chain, from H ₂O and CO ₂ to kerosene, in a pilot-scale solar tower. We evaluate the performance of the solar reactor—the cornerstone technology—based on five primary metrics (namely, reaction selectivity, syngas quality, fuel purity, energy efficiency, and material stability) and experimentally validate its stable operation and full integration in the solar tower fuel plant.

Abstract

For the first time, the thermochemical production of kerosene using solar energy, water, and CO ₂ is demonstrated in a fully integrated solar tower fuel plant. Solar-made kerosene can replace fossil-derived kerosene and further make use of the existing global jet fuel infrastructures and engines, which are particularly critical for the long-haul aviation sector. This pioneer technological demonstration, performed at a pilot scale relevant to industrial implementation, represents a critical milestone on the path toward the production of sustainable aviation fuels.