How is Erbium-169 made

Synthetic Fuels: How Does It Work?

E-fuels have entered the public debate: Because such CO2-reduced fuels can be transported, stored and refueled as before. Conventional gasoline and diesel engines could also help to protect the climate. Marc explains how these synthetic fuels are made and how they help us achieve a climate-neutral vehicle fleet.

Biofuels, e-fuels, hydrogen - in March I reported for you about the possibilities of alternative fuels for the energy transition in Germany. Because of the many positive reactions in this post, I would like to go a little deeper into what I think is extremely exciting topic and explain to you how synthetic electricity-based fuels - the so-called e-fuels - are actually produced. Because the production is the most important sticking point in the energy debate when talking about synthetic fuels.

Before I go into more detail about production, I would like to briefly mention the advantages of such regenerative fuels for the energy transition:

The goal of the energy transition for transport is to organize our mobility in the future in such a way that we release less and less CO2 from fossil fuels into the environment when transporting people or goods, because otherwise the greenhouse gas effect would be further intensified. This is where renewable synthetic fuels such as e-fuels come into play: The idea behind this is to artificially produce fuels such as diesel or gasoline without resorting to fossil sources and continue to release CO2 into the atmosphere that has been bound in crude oil or natural gas over millions of years. The practical advantage of these liquid fuels over electric drives, which rely on electricity and rechargeable batteries for storage, is that they are available to motorists as usual via the existing filling station network and can be used in normal diesel or gasoline engines. Due to the possibility of admixing with fossil fuels, this can also be done in stages and, as the admixture rate increases, the fossil component can be gradually replaced.

Power-to-Liquid: How e-fuels are made

In contrast to the fossil fuels such as conventional diesel or gasoline, which you draw at the gas station nowadays, synthetic fuels are not obtained from crude oil, but are artificially produced in a large technical facility. The most important ingredients for the production are: water, recycled carbon and, at best, green electricity from wind and hydropower or solar energy. Put simply, the actual production then proceeds as follows: Water is converted into hydrogen (and oxygen) by electrolysis (with the help of electrical energy) and the hydrogen is then mixed with recycled carbon - previously e.g. B. obtained from the CO2 in the atmosphere - connected. This creates a liquid hydrocarbon compound whose chemical structure can be adjusted during production so that it ultimately has the same properties as diesel or gasoline or even exceeds them, so that you can refuel your cars without any problems as before.

The most valuable ingredient in the production of such synthetic fuels is electricity. That is why the process is called “power-to-liquid” among experts - electricity is converted into liquid fuel and the product is ultimately referred to as e-fuel (E = electric).

Why synthetic fuels are environmentally friendly

In production processes such as power-to-liquid (PtL) with CO2 that was previously removed from the air, a closed carbon cycle is created, at the end of which no more CO2 is released than was previously bound. With the help of today's technology, carbon can be recycled and reused again and again in a circulatory system. The bottom line is that, unlike fossil fuels, the production of renewable synthetic fuels does not emit any additional CO2 into the atmosphere.

In contrast to fossil, conventional diesel or gasoline fuel, synthetic fuels also have another advantage for the environment: They can be constructed in such a way that significantly fewer pollutant emissions are produced when they are burned. And another property makes such fuels even more attractive: they could be mixed with fossil fuels in a transitional phase and also refueled in existing vehicles so that they can already contribute to climate protection through their usual use without having to be replaced.

Even if we should have ten million battery-electric vehicles in Germany by 2030, there will probably still be more than 35 million “conventional” cars with internal combustion engines on the road. In order to achieve the climate targets, we also need solutions for this vehicle fleet. In addition to increasing efficiency and expanding domestic green electricity generation, low-CO2 fuels are therefore a promising pillar for an affordable energy supply in the future.

And if at some point all cars actually run on battery-electric or fuel cells: Airplanes, ships and parts of heavy goods traffic will continue to use conventional fuels in the future. Combustion engines that run on CO₂-neutral synthetic fuels are therefore an indispensable path. Because in order to fight climate change, we have to make use of all the options available to us.

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In a nutshell:
Synthetic fuels have the potential to become one of the future technologies for the energy mix of climate-friendly mobility. Their great advantage is that their production with green electricity and in closed carbon cycles is climate-neutral and that we as a society can rely on an adequate and secure supply, that we do not need new investments in the infrastructure of our transport system and that combustion engines have a climate-neutral perspective.

About this author

Marc, 46, lives in Hamburg near the port. Climate protection is very important to him. But he would like to see a debate that explores the scope for shaping our future more.

Photos: vladstar -; olly -