The new "solar" kerosene to fly zero-emission aircraft

For the next holidays will we choose the low-cost flight that will emit 300 kilograms of carbon dioxide per passenger, or will we prefer to do the good of the environment with a trip to the mountain behind the house? In the future, solar kerosene could save us this difficult choice. This eco-sustainable synthetic fuel, in fact, is a probable protagonist in the decarbonisation process of the air transport sector, responsible for about 25% of the carbon dioxide emitted every year by man. The first airline to use this carbon-neutral kerosene will be Swiss International Air Lines (Swiss), part of the Lufthansa group, thanks to a new partnership with Synhelion, a company that "turns sunlight and CO 2 into fuel" , as it clearly announces on its website.

Biofuels may not be so good for the environment Despite being presented as a green way to reduce dependence on oil, a new study in the United States reveals effects worrying undesirable The startup Founded as a spinoff of the Zurich Polytechnic, Synhelion has been defined by the co-founder Gianluca Ambrosetti as a "small but ambitious company immersed in the Swiss Alps". Since 2016 he has been working on a process based on the use of sunlight to produce synthetic fuel, or solar fuel. By means of large moving mirrors, called heliostats, the sun's radiation is collected and directed to a receiver, a “solar tower”. This leads to an increase in the temperature inside the receiver: when this exceeds 1500 ° C, a reaction is triggered that transforms water vapor and carbon dioxide into a mixture of hydrogen and carbon monoxide called syngas.

This gas is then converted via standard industrial processes into gasoline, diesel or liquid jet fuel. Excess energy is stored thanks to a thermal energy storage (Tes), allowing continuous operation 24 hours a day, seven days a week, even in the absence of solar radiation. "The whole process takes place in full climate neutrality since the fuel, when burning, produces the same amount of carbon dioxide necessary for its manufacture", explained Ambrosetti. The carbon footprint, not affecting the final concentration of carbon in the biosphere, is therefore equal to zero.

How long are the electric planes to take off? By far the biggest problem is batteries, which are currently not suitable for long-distance flights: there are those who are trying to invent alternatives The interest of Europe In Europe there is a strong interest in this new technology, as suggested by the 4 million that the German government invested in Synhelion last October. With another 16 million Swiss francs (about 15 million and 740 thousand euros), arrived in November from other investors (Orchilla, Sms group, Cemex Ventures, Amag, as well as some private individuals), the company is currently building the first plant in the world for the industrial production of solar fuel. It is located in Jülich, Germany, and will have an 80,000 square meter receiver.

The technology will therefore soon be commercialized and the first solar kerosene planes are expected to fly as early as 2023. If large-scale production goes as planned, Synhelion has estimated that half of Switzerland's fuel needs by 2030 for aviation will be covered thanks to its sustainable product, an amount that is around 875 million liters per year.

The advantages "Our next generation carbon-neutral solar kerosene is a substitute for economically and ecologically viable fossil fuels, "said Synhelion CEO and co-founder Philipp Furler. In addition to being a way to produce clean energy, it is also very competitive from a cost point of view. The energy conversion process is more efficient than other more popular technologies, and the company aims to further increase it.

In addition, from a chemical point of view it is analogous to fossil fuels and therefore compatible with existing infrastructures. This means that there is no need to convert or retrofit combustion engines, refineries, distributors or filling stations to switch to solar kerosene. Furthermore, Synhelion's technology is a promising opportunity to decarbonise the aviation sector, but it could also be applied with great versatility to other means of transport such as cars, ships and trucks.

And that's not all: the new solar kerosene is also advantageous compared to other forms of biofuels, since being in liquid form it is easier to store and transport than, for example, biogas. Another important aspect that makes Synhelion's syngas cheaper than other biofuels is that it does not compete with other sources, ie it is not necessary to subtract biomass useful for example for the food industry. Many biofuels, in fact, derive from plant sources such as soy, corn, sugar cane and wheat, so their production takes away food resources. But for solar kerosene the “food versus fuel” debate is not a problem.

"We want to be the pioneers in the use of solar fuels - said Swiss CEO Dieter Vranckx - hence our involvement with Synhelion it is a key element in our long-term sustainability strategy ". Swiss is the sole buyer for now, but Synhelion is forging partnerships with more and more investors and it is easy to imagine that other airlines will soon switch to solar fuels. "We believe in a globalized world connected through climate-friendly mobility - said Furler -. The commitment of Swiss and the Lufthansa group shows how the aviation sector is definitely interested in solar fuels".