Climate-neutral flying: German start-up develops solar fuels

"Kerosene is cheap, the production costs of alternative aviation fuels have so far been high. A process invented in Switzerland and further developed in Germany is now set to change that.

 

Despite the energy crisis, kerosene is still cheap. Airlines currently pay around one dollar for a liter of fuel. This is a problem for airlines that want to reduce their CO2 emissions, because the production costs of alternative energy sources have so far been far higher. A process invented in Switzerland and further developed in Germany is now set to change that. 

 

The start-up Synhelion uses solar heat to produce synthesis gas. This gas is the raw material for high-purity kerosene. In contrast to other processes currently being discussed, it is not necessary to first generate electricity in order to produce hydrogen. According to co-founder Philipp Furler, this reduces the energy requirement by around a third. Accordingly, the space required for energy production also decreases.

 

In the laboratories of the Swiss Federal Institute of Technology, a research group to which Furler belonged originally developed a solar reactor in which the synthesis gas – a mixture of hydrogen and carbon monoxide – was formed directly through solar radiation. As fascinating as this technology, which has been tested in a test facility on the roof of the university, is, it still has a serious disadvantage: Even in the sun-kissed parts of the world, it only shines for an average of twelve hours a day. Synhelion is modifying the process for the first plants that are now being built in Jülich and in Spain. Mirrors distributed on the ground catch the sun's rays and direct them to a receiver. It sits in a tower and heats a liquid to more than 1200 degrees Celsius. Two-thirds of the heat is initially stored in an artificial rock so that the fuel production plants can run around the clock.

 

“We will be the first adopters”

 

The heat of the sun heats a reactor into which the raw materials are fed. In theory, it would be enough to use only carbon dioxide and water, but in order to work in a climate-neutral manner, the carbon dioxide would first have to be separated from the air. That in turn is still very expensive, it costs between 600 and 1000 euros for a ton. For this reason, Synhelion is using a mixture of carbon dioxide and methane produced from organic waste for the first plants. 

 

Furler promises that it is possible to do without biogenic substances in the future.

 

Dieter Vranckx, head of the Lufthansa subsidiary Swiss, confirms that Synhelion is a serious undertaking: "We will be the first to use it." However, his aircraft will not get very far with it for the time being. The first commercial plant, which is scheduled to go into operation in Spain by the middle of the decade, will initially only produce 500,000 liters of climate-friendly aviation fuel per year. But Synhelion wants to grow quickly, to which not only a purchase guarantee from Lufthansa, but also the capital of the Italian oil company Eni should contribute. By the end of the decade, 875 million liters are to be produced annually at far lower costs.

 

Nevertheless, Lufthansa board member Christina Foerster calls for political support: "We need effective CO2 compensation mechanisms." Intra-European emissions trading alone cannot solve this, because London and Istanbul are two major hubs for international air traffic right behind the borders of the European Union. The regulation is effective in the United States, where the additional costs for climate-neutral fuels are reimbursed through tax credits.

 

With the help of synthesis gas, not only aviation fuels but also synthetic fuels for road traffic could be produced. Helmut Ruhl, head of the large Swiss car retail chain Amag, is therefore committed to Synhelion. He would love to supply Formula 1 with the solar fuel."