The EU-funded SOLAR-JET project launched in June 2011 has successfully produced ‘solar’ kerosene directly from synthesis of sunlight, water and carbon dioxide. This is a key step towards large-scale manufacturing of ‘clean’, sustainable fuels, which potentially could have far-reaching consequences for the future aviation industry.
The scientists involved in the project have created a novel process technology using concentrated sunlight to convert carbon dioxide and water to a so-called synthesis gas (syngas). This is achieved through a redox cycle with metal-oxide based materials at high temperatures. Lastly, the syngas, a mixture of hydrogen and carbon monoxide, is converted into kerosene by using commercial Fischer-Tropsch technology.
This new solar reactor technology could be also utilised to produce liquid hydrocarbon fuels suitable for more sustainable transportation.
"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, the leader of fundamental research and development of the solar reactor at ETH Zürich.
Dr. Andreas Sizmann, the project coordinator at Bauhaus Luftfahrt commented on the announcement: "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.
Dr. Sizmann believes that the real challenge will be to demonstrate that the production chain is cost-efficient, which would require efficiencies of about 15%. Improvements in materials, reactor geometry, heat management, gas management and reactor size could help to achieve higher efficiencies in the fuel production process.
“Sunlight, carbon dioxide and water are basically an unlimited feedstock. When the long term goal of 15% overall energy efficiency is reached, 20,000 litres of kerosene per day could be produced in a solar tower system of one square kilometre,” adds Dr. Sizmann.
Despite the fact that the syngas production is still in the development stage, the processing of syngas to kerosene is already being adopted by companies such as Shell on a global scale.
"This is potentially a very interesting novel pathway to liquid hydrocarbon fuels using focussed solar power," said Professor Hans Geerlings at Shell. "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."
Photo Source: Royal Society of Chemistry