In this article you will find everything you need to know about synthetic fuels, an alternative to traditional fossil fuels.
Since the origins of the automobile at the end of the 19th century, man has been trying to find more efficient and, above all, more economical alternatives to traditional fossil fuels. The electrification of the automobile seems to be one of the most viable solutions to end dependence on oil, but it is not the only avenue currently being explored.
The electric car and the hydrogen fuel cell car are now joined by synthetic fuels as a solution to prevent the internal combustion engine from disappearing completely, especially in Europe, which will end up approving regulations that will ban the sale of new combustion cars from 2035 onwards.
With e-fuels among the energy options that will be allowed beyond the 2035 horizon, many people have doubts about these synthetic fuels. For that reason, in this article we are going to discover everything you need to know about e-fuel, from its origin to its production and even the price per liter it is expected to reach in the future.
What is a synthetic fuel and what is its origin?
Let’s start with the basics. Synfuel is a carbon dioxide (CO2)-neutral fuel made from hydrogen. Synthetic gasoline and diesel can power internal combustion engines that require little or no modification to use this fuel in place of traditional ones.
E-fuel is considered a sustainable fuel because it uses carbon dioxide captured directly from the atmosphere, water and energy from renewable sources such as wind and solar power.
Once this fuel is consumed in a combustion engine, the same emissions captured for the production of the fuel are generated, hence the CO2-neutral balance, because no more greenhouse gases are expelled than had to be captured from the atmosphere to produce the synthetic gasoline.
Furthermore, unlike biofuels, synthetic gasoline is not obtained using raw materials that could be used as a source of human food, which does not make it a direct competitor and does not encourage speculation or increase the price of these foods.
Its origin is found in essential elements in the earth, such as oxygen, hydrogen and carbon dioxide. Electrical energy is also needed, which is obtained from clean sources, and a chemical and physical process is sufficient for the production of synthetic fuels.
How are synthetic fuels produced?
Synfuels are produced through a chemical and physical process divided into several steps. The entire manufacturing process is supported by electrical energy obtained from renewable sources, such as wind and photovoltaic, while water and carbon dioxide are the only “ingredients” needed to produce synthetic fuel.
These are the steps involved in obtaining e-fuel:
- The oxygen (O2) and hydrogen (H2) that make up water are separated by electrolysis at temperatures above 800 ºC. The oxygen is expelled into the atmosphere and the green hydrogen, obtained using renewable energy, will be the element that we will keep to produce synthetic fuels.
- To capture carbon dioxide (CO2) from the air, absorption towers are used in some refineries. These towers function as a kind of sponge that traps the carbon dioxide, using heat that is reused from the subsequent process of converting methanol (CH3OH) into synthetic gasoline.
- Using high pressures and temperatures, as well as catalysts, it is possible to combine the captured hydrogen and carbon dioxide to react with each other and generate methanol in a dedicated production plant.
- Pressure, temperature and catalysts are then used again to transform this methanol into synthetic gasoline, although at this point the fuel obtained is not yet suitable for combustion engines.
- Finally, the mixture obtained is purified by chemical processes such as distillation, resulting in functional synthetic fuel.
How do synthetic fuels work?
Once the synthetic fuel is produced, it can be used in internal combustion engines without any required modifications, so its operation is identical to that of gasoline and diesel derived from petroleum. Moreover, e-fuel is in a liquid state, so refueling and transportation is carried out in the same way as fossil fuels.
It is worth mentioning that once the e-fuel is combusted in a heat engine, gases are generated and expelled into the atmosphere through the exhaust system.
Therefore, they are not considered emission-free cars, as are electric and hydrogen cell vehicles, although net emissions are neutral because they do not exceed the amount of carbon dioxide captured from the atmosphere for the production of the synthetic fuel.
Are synthetic fuels the future?
Answering this question is more complicated than it seems. There are two possible scenarios: that they are an alternative to electric and hydrogen cars, and that their cost prevents them from becoming a viable solution for the future.
For countries such as Germany and Italy, and automakers such as Porsche (the biggest proponent of e-fuels), Mazda, Lamborghini and Audi, synthetic fuels are a future option with the potential to endure over time, allowing the automotive industry to continue developing and marketing internal combustion engines beyond 2035.
However, at present, few automotive companies continue to allocate funds and work to research and development of the internal combustion engine. Most brands are betting on electric cars, while a somewhat smaller number are beginning to see hydrogen as an interesting option for the coming years.
For the time being, Europe has approved that e-fuels will be legal beyond 2035, the year in which the sale of new cars with combustion engines will be definitively prohibited, which also includes hybrids and gas-powered cars.
However, it is also true that synthetic fuels are still at an early stage of development. Porsche is the manufacturer that is making the most progress in standardizing them, with a plant in Chile that, as of 2020, will be producing 130,000 liters of synthetic gasoline per year. In 2024 they expect to expand this figure to 55 million liters, and in 2026 to reach 550 million liters.
Another scenario in which it is possible that synthetic fuels will have an outlet is in competition and in areas where electrification is not feasible, such as air and maritime transport.
e-fuel, what is its price?
Talking about the price of synthetic fuels is getting too far ahead of ourselves. It is unlikely that we will see this fuel at the pump before 2030, and if we do, it will be substantially more expensive than a liter of conventional gasoline and diesel.
Some experts estimate that its current price is 10 times higher than that of traditional gasoline, while a recent study by Transport & Environment claims that a liter of synthetic gasoline will cost 2.80 euros per liter in 2030. Other sources argue that by the end of this decade it could cost between 3 and 4 euros per liter.
The main reasons for the high price of synthetic fuel is the enormous amount of energy used to produce it and the need to import it from abroad. At these prices, e-fuel is considered a luxury item.
When were synthetic fuels created?
The creation of synthetic fuel is attributed to Fiedrich Bergius, a German scientist and Nobel Prize winner in Chemistry. Bergius, who came to live in Madrid after the German defeat in World War II before settling in Buenos Aires, succeeded in producing synthetic fuels by hydrogenation of coal in 1927.
Since then, other methods for obtaining synthetic gasoline from coal, natural gas or biomass have been investigated.
Spain has also tried to develop synthetic fuels, either through the distillation of oil shale in Puertollano during the 1930s, or a project in Franco’s Spain that sought to produce synthetic oil in the 1940s, which resulted in the creation of the company ENCASO, which would end up commercializing lubricants.
What is synthetic diesel?
Synthetic diesel falls into the category of e-fuel, but its production varies slightly from that of synthetic gasoline in the final refining process. Synthetic diesel is produced from hydrogen, water and carbon dioxide, like synthetic gasoline.
Once the hydrogen and carbon dioxide are combined, the reaction generated at high pressure and temperature results in a blue liquid known as “blue crude”. On this basis, a refining process similar to that of conventional diesel is carried out, making it suitable for use in internal combustion engines.