This is the first time that Audi develops a fuel from which the energy comes from a renewable hydroelectric source. Synthetic fuel extracts hydrogen from water and mixes it with CO2, reducing carbon emissions to the atmosphere almost completely. The company has ensured that these e-fuels are almost carbon neutral. To produce it, the hydroelectric station produces hydrogen and oxygen from water, a process known as electrolysis. Then, the oxygen reacts with CO2 and a long chain of hydrocarbon compounds is formed. Finally, these compounds are separated to create e-diesel and waxes, which are used in other areas of the industry. Thanks to a new technology, Audi can handle e-diesel production efficiently in compact units, which makes it more economical.
Audi has been working on another e-diesel pilot project since 2014 with the sun-fire energy technology corporation in Dresden, Germany. In addition, the brand has several departments in some of its facilities where it manufactures synthetic methane (e-gas) for A3, A4 and A5 models. The Ingolstadt brand is also investigating the manufacture of synthetic fuel e-gas together with specialist partners.
Audi is very focused on the development of synthetic fuels, something that they have already dubbed e-fuels. They are not science fiction they are already producing e-diesel from renewable energy, water and carbon dioxide at their plant in Laufenburg. The next objective is to produce up to 400,000 liters per year. They also have since 2013 their e-gas, a more sustainable CNG that already feeds the German network.
Now it’s the turn of the e-gasoline, a synthetic fuel that had been investigated, but with which had not yet been tested. Now for the first time they have obtained 60 liters of e-gasoline, enough to test it in a bank of engines. The main advantage of this fuel is that it does not depend on oil, but rather it is a liquid isooctane that is produced in the following way.
With the help of other companies, it starts with the production of isobutene gas (C4H8) and then additional hydrogen is used to transform it into isooctane (C8H18). The result is that being free of sulfur and benzene it generates less pollutants when it burns. Having a high purity is also debating whether it could increase the compression of the engine and thus achieve greater efficiency.
Currently to make e-gasoline biomass is required, but in the future it is expected to modify the process to be able to use CO2 and hydrogen produced from renewable sources. The brand of the four rings Audi has high hopes for their e-fuels to reduce emissions in combustion engines. We will see what conclusions are drawn from these first tests with e-gasoline.