Overview
Secure, sustainable and scalable supply of renewable aviation fuel.
The aim of the SOLAR-JET project is to demonstrate a carbon-neutral path for producing aviation fuel, compatible with current infrastructure, in an economically viable way. The SOLAR-JET project will demonstrate on a laboratory-scale a process that combines concentrated sunlight with CO2 captured from air and H2O to produce kerosene by coupling a two-step solar thermochemical cycle based on non-stoichiometric ceria redox reactions with the Fischer-Tropsch process. This process provides a secure, sustainable and scalable supply of renewable aviation fuel, and early adoption will provide European aviation industries with a competitive advantage in the global market.
The partners within the SOLAR-JET project combine all necessary competencies for the realisation of project objectives, including: a unique high-flux solar simulator, a state-of-the-art computer simulation facility and software to significantly reduce the required number of experiments, and a Fischer-Tropsch unit for producing the first ever solar kerosene. These efforts are further complemented by assessments of the chemical suitability of the solar kerosene, identification of technological gaps, and determination of the technological and economical potentials.
The outcomes of SOLAR-JET would propel Europe to the forefront in efforts to produce renewable, aviation fuels with a first-ever demonstration of kerosene produced directly from concentrated solar energy. The fuel is expected to overcome known sustainability and/or scalability limitations of coal/gas-to-liquid, bio-to-liquid and other drop-in bio-fuels while avoiding the inherent restrictions associated with other alternative fuels, such as hydrogen, that require major changes in aircraft design and infrastructure. The process demonstrated in SOLAR-JET eliminates logistical requirements associated with the biomass processing chain and results in much cleaner kerosene and represents a significant step forward in the production of renewable aviation fuels.
Funding
Results
1. Technology assessment framework and state-of-the-art review:
An assessment framework has been established for the quantitative and traceable comparison of different technology options and of very different fuel paths, such as solar-thermochemical versus biological pathways. The assessment method is based on the principle of a weighted decision matrix. Firstly, a set of criteria is defined for the comparison: the fuel readiness level, technical compatibility, substitution potential, well-to-wake greenhouse gas emissions, total reserves left, production costs, water footprint, air quality emissions and cycle efficiency.
Then quantitative measures (metrics) were defined, which assign scores for each of the mentioned criteria for all investigated fuel paths. The scores are obtained from the primary performance metrics of the fuel path with respect to each criterion by pre-defined transfer functions which provide traceability in the process. Weighting factors, which adjust the relative importance of the single criteria, reflect different scenarios and priorities for the fuel path being evaluated. It is possible to turn criteria into prerequisites that have to be fulfilled, while a weight of zero omits a criterion in the further analysis. The assessment framework thus allows the quantitative evaluation of different fuel paths within different scenarios. A review of the state-of-the-art of technology shows that most process steps are already implemented in an industrial environment, and that these process steps have been proven to be applicable with respect to efficiency and cost. However, the thermochemical reaction and the CO2 capture from the atmosphere are in relatively early stages of their development and require further research. These are possible bottlenecks but the largest progress is expected to occur for these two processes.
An expected result is that the final assessment will show the key advantages and disadvantages of the thermochemical fuel path in direct comparison with other renewable fuel path options. Also it will show the potential impact that key developments can have in the relative performances of fuel paths.
2. Synthesis gas production in the prototype reactor:
Syngas, short for synthesis gas, is the generic term for a mixture of carbon monoxide (CO) and hydrogen (H2). The name comes from the fact that syngas can be used for chemical syntheses of a large variety of products. Syngas production by simultaneous splitting of H<su
Technical Implications
It is expected that the experience gained with the existing reactor and with computational fluid dynamic modelling will serve to create an enhanced solar reactor design and to evaluate the potential of the process for scaled-up operations to an industrial level. The synthesis of the theoretical and experimental results, combined with an overall fuel production path analysis, will provide information on the technological and economic potential of the ceria cycle and the solar fuel production chain that need to be addressed to make full use of this technology potential. The evaluation in the comprehensive assessment framework will show the inherent advantages and disadvantages of the thermochemical ceria cycle as compared to other renewable alternative fuel paths.
Policy implications
The project has the potential to contribute to future carbon-neutral aviation, either through the process demonstrated by SOLAR-JET or through the scientific and technological advancements generated that may open new and better perspectives. Countries in Southern Europe with large amounts of annual direct solar irradiation might then benefit from an influx of investment and revival of their economies.
Strategy targets
Innovating for the future: technology and behaviour:
- A European Transport Research and Innovation Policy
- Promoting more sustainable development