Page 38 - The STAT Trade Times September 2022 Issue

interview

Is that why SAF is so expensive generate high-temperature process heat. All sectors need to adopt decarbonisation
right now? With this solar process heat, we drive ther- strategies. Air cargo is integral to this, and
There's barely any available on the market mochemical reactions to produce syngas, they will also have to work with sustainable
right now. The only kind of SAF that is and this gas is then liquefied the same aviation fuels. Even though you can, for
available right now is biofuel, which is of way you would do in a power-to-liquid example, compensate CO2 emissions by
biogenic origin, and prices are relatively process where you would also produce planting trees, we believe that you really
high. Demand is much higher than what is the syngas and then liquefy it. The only have to solve the problem at the core,
offered. Currently, the conditions are ideal difference is that we don't need any which is to replace fossil fuels and stop
for SAF producers like us to start ramping electricity here. We work purely with solar using them entirely.
up. Because now you can really see that heat to produce syngas, and that's why
there's a lot of traction in the market. we call them solar fuels. Can you give us a breakdown of
the solar fuel technology, a little
What are the different types What are the biggest challenges about the process and the infra-
of SAF currently available in when it comes to SAF right now? structure that's required as part
the market? With SAF, it’s important to understand that of the solar fuel production?
There are biofuels, where you gasify biomass these are new technologies. The market We have a field of moving mirrors which
and produce liquid fuel. Then there is power- is now demanding these fuels, and the track the sun. The mirrors concentrate
to-liquid which produces what is known as technologies are ready to be implemented. the sunlight onto the top of a tower. At
‘e-fuel’. In this case, you need to use renew- However, there are no large-scale synthetic the very top of the tower, you can see a
able electricity. With this electricity, you drive fuel plants installed yet. It's important not very bright spot where all the sunlight
electrolysis to produce hydrogen and add just for our technology but also for the oth- gets concentrated. Here is where all the
carbon dioxide. Through another process, er synthetic fuel technologies to be able to magic happens. Here, a receiver absorbs
you then get syngas which is the intermedi- have a scalable plant model. So, we have to the concentrated sunlight and turns it
ary product you need to then produce liquid go one step after the other, especially with into process heat. This process heat is
fuel. Once you have produced syngas in a new technology, you cannot immediately then used to drive the reactor, where we
sustainable manner, you can liquefy it with build a huge facility. Economies of scale are turn a carbon source and a water source
existing industrial technology. Then you really important. So, once you have a really into syngas – a mixture of hydrogen and
have a synthetic liquid fuel, which is, in this large plant, it can produce at competitive carbon monoxide. This syngas is then liq-
case, also called e-fuel or electrofuel. The prices. However, the first small plants are not uefied with the Fischer-Tropsch process,
technique that we have developed is solar yet as economical as the future larger plants which is a standard industrial process to
fuels. For this, we don't take the detour via will be. That's a typical challenge that you convert carbon monoxide and hydrogen
the generation of electricity, but instead, we always face when you develop hardware into liquid hydrocarbons. The Fischer-
directly use solar heat. So, we concentrate technology. And as I just said, there's a lot of Tropsch process is well established and
solar radiation and use that to directly drive hardware. So, it's very expensive to do this has been conducted for many years
our reactors to produce synthetic fuel. development to be able to scale up. already to produce liquid fuels. So, the
We call this the ‘sun-to-liquid’ tech- challenging part is to produce the
nology, as we use solar heat directly. How do you think that this can syngas in a renewable way. Once you
Essentially, the process involves concen- impact the supply chain and have that, liquefying it is a standard
trating the solar heat and using that to cargo in general? industrial procedure.

In August, Synhelion produced solar syngas on an industrial scale for the first time in the world on the DLR multi-focus solar tower.

Photo: Synhelion

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