The Social Democratic Party (SPD) and the Green Party are in favor: phasing out combustion engines for newly registered vehicles by 2035. The Free Democratic Party (FDP) wants to save the internal combustion engine with E-Fuels. The European Parliament has already voted and initiated the new regulation. German Federal Minister for the Environment, Steffi Lemke, announced that Germany will vote in favor of phasing out combustion engines in the EU.

However, the FDP is once again interfering with the plan and proposes a compromise: combustion engine vehicles powered by synthetic fuels (E-Fuels) should still be allowed to be registered after 2035, but they must be proven to be carbon-neutral_.

What are E-Fuels exactly?

E-Fuels are fuels in which traditional crude oil is replaced as the source of raw material. Essentially, it aims to keep diesel and gasoline, and thus internal combustion engines, alive. However, in this case, crude oil is replaced by a synthesized compound of hydrogen and CO₂.

In the first step, hydrogen is produced through electrolysis, which involves splitting water (H₂O) into its components, hydrogen and oxygen. The hydrogen can then be used further, and the only byproduct is oxygen.

Hydrogen is then combined with CO₂ in a chemical conversion process, resulting in the formation of carbon monoxide (CO), hydrogen (H₂), and water. The carbon monoxide then reacts with hydrogen to form a synthesis gas that serves as a substitute for crude oil. In the final step, the synthesis gas is further processed into E-Fuels in a refinery.

Are E-Fuels truly climate-neutral?

In theory, they can be produced in a climate-neutral manner, yes. However, in the first production stage, hydrogen electrolysis requires a large amount of electricity, which must be generated solely from renewable energy sources. This results in the production of so-called “green hydrogen”.

Furthermore, the CO₂ used in the production of the crude oil substitute must be captured from the atmosphere (Carbon Capture method) or must not be newly produced at least. This is because the complete amount of CO₂ is released again during the fuel production process. If these two conditions are met, the produced E-Fuels would be truly climate-neutral.

Current problems with E-Fuels

The main problem is the current state of research and development of E-Fuels. They are still far from being viable as a fuel. On the one hand, the production is very expensive – one liter of e-diesel would cost around five euros. But more importantly, the efficiency is very low.

It ranges only between 10 and 15 percent, resulting in very inefficient utilization. For comparison, diesel and gasoline currently have an efficiency of around 20 to 30 percent. However, in city traffic, the efficiency of internal combustion engines can drop to below five percent. Electric motors can achieve an efficiency of over 95 percent in some cases.

However, this largely depends on the application and design. In an electric vehicle, the efficiency typically ranges between 65 and 70 percent. Losses primarily occur during battery charging processes.

Finally, there is also the question of whether enough CO₂ can be captured with so-called carbon capture facilities to ensure climate-neutral production.

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