The conversion from fossil to renewable fuels is one of the most important challenges of the future. The “SUN-to-LIQUID” project, funded by the European Union and Switzerland, was the first to produce solar kerosene. The production of renewable kerosene from water and CO2 is made possible by concentrated sunlight.
“The SUN-to-LIQUID reactor technology and the integrated chemical plant were validated under the typical conditions for industrial fuel production,” says Prof. Aldo Steinfeld of ETH Zurich, who heads the development of the solar thermal chemical reactor. “The demonstration of this technology could have a major impact on the transport sector, especially for aviation and shipping, which continue to rely on liquid fuels over long distances,” adds project coordinator Dr. Andreas Sizmann of Bauhaus Luftfahrt.
From laboratory to sunlight
In the previous SOLAR-JET project, the researchers developed the technology and produced solar kerosene under laboratory conditions for the first time. SUN-to-LIQUID took this technology to the next development stage and tested it under real conditions on a solar tower. For this purpose, a unique solar plant was erected on the premises of the IMDEA Energy Institute in Móstoles, Spain, especially for the project. “A heliostat field following the sun concentrates the sunlight by a factor of 2500, which is three times the concentration of solar systems currently used for energy generation,” explains Dr. Manuel Romero of IMDEA Energy. The very high solar radiation intensity, confirmed by flux density measurements carried out by the German Aerospace Center (DLR), makes it possible to reach temperatures of over 1500 degrees Celsius in a solar reactor.
The reactor developed by the project partner ETH Zurich produces a so-called synthesis gas from water and CO2 – a mixture of hydrogen and carbon monoxide. A special Fischer-Tropsch plant developed by project partner HyGear converts this synthesis gas into kerosene on site.
Reduction of CO2 emissions by more than 90 percent
Compared to fossil fuel, SUN-to-LIQUID reduces CO2 emissions by more than 90 percent. Since solar fuel production is best suited for desert locations, there is no competition for agricultural land. The plant is intended to extract the raw material CO2 from the atmosphere in the long term. The future global demand for kerosene could be covered by regenerative solar fuels that are compatible with the existing fuel infrastructure.
About the project
SUN-to-LIQUID is a four-year project funded by Horizont 2020 – the European Commission’s research and innovation funding programme – and the Swiss State Secretariat for Education, Research and Innovation (SER). The project started in January 2016 and will end in December 2019. SUN-to-LIQUID brings together leading European research institutions and companies in the field of thermochemical solar research: ETH Zurich, IMDEA Energy, DLR, Abengoa Energía and HyGear Technology & Services B.V. The coordinator Bauhaus Luftfahrt e.V. is responsible for the technology and systems analysis. ARTTIC supports the research consortium with project management and communication.
Sources: DLR, Bauhaus Aviation