Solar Reactor turns Sunlight, Water and Carbon Dioxide into Jet Fuel

The production of renewable kerosene from sunlight, water and carbon dioxide (CO2) has been demonstrated by the EU-funded SOLAR-JET project. This synthesized “solar” jet fuel has the potential for revolutionizing the future of aviation.

The process also may be able to produce any other type of fuel for transportation, including diesel, gasoline or pure hydrogen, more sustainably.

The exploration of thermochemical pathways driven by concentrated solar energy was participated in by notable research organizations from academia to industry, such as ETH Zürich, Bauhaus Luftfahrt, Deutsches Zentrum für Luft- und Raumfahrt, ARTTIC and Shell Global Solutions.

A breakthrough solar reactor technology has been created to produce liquid hydrocarbon fuels suitable for more sustainable transportation.

Unlimited Solar Kerosene

“Increasing environmental and supply security issues are leading the aviation sector to seek alternative fuels which can be used interchangeably with today’s jet fuel, so-called drop-in solutions”, said Dr. Andreas Sizmann, of Bauhaus Luftfahrt. “With this first-ever proof-of-concept for ‘solar’ kerosene, the SOLAR-JET project has made a major step towards truly sustainable fuels with virtually unlimited feedstocks in the future.”

The SOLAR-JET project proved out an innovative technology and process for using concentrated sunlight to convert carbon dioxide and water to a so-called synthesis gas, or Syngas. This is achieved through a redox (reduction-oxidation) cycle with metal-oxide based materials at high temperatures. The syngas, a mixture of hydrogen and carbon monoxide, is finally converted into kerosene by using commercially available Fischer-Tropsch technology.

The Fischer–Tropsch process is a combination of chemical reactions which converts a mixture of carbon monoxide and hydrogen into liquid hydrocarbons. It was first developed by Franz Fischer and Hans Tropsch at the Kaiser-Wilhelm-Institut für Kohlenforschung in Mülheim an der Ruhr, Germany in 1925.

“The solar reactor technology features enhanced radiative heat transfer and fast reaction kinetics, which are crucial for maximizing the solar-to-fuel energy conversion efficiency” said Professor Aldo Steinfeld, who lead the research and development of the solar reactor.

Syngas to Kerosine

Even though the solar-driven redox cycle for syngas production is still at an early stage of development, the processing of syngas to kerosene is already being deployed by companies, including Shell, on a global scale. This combined approach has the potential to provide a secure, sustainable and scalable supply of renewable aviation fuel and more generally for transport applications. Moreover, Fischer-Tropsch derived kerosene is already approved for commercial aviation.

“This is potentially a very interesting novel pathway to liquid hydrocarbon fuels using focussed solar power”, said Shell’s Professor Hans Geerlings. “Although the individual steps of the process have previously been demonstrated at various scales, no attempt had been made previously to integrate the end-to-end system. We look forward to working with the project partners to drive forward research and development in the next phase of the project on such an ambitious emerging technology.”

The Solar chemical reactor demonstration and Optimization for Long-term Availability of Renewable JET fuel project (SOLAR-JET) began in June 2011. In its first phase, the technical feasibility of producing solar kerosene was proven.

The next phase of the project, ending in 2015, will involve the optimisation of the solar reactor and assessing the techno-economic feasibility of industrial scale implementation.

Image Credit: SOLAR-JET