Luxury car maker Audi has announced that it is making synthetic diesel fuel from just water and carbon dioxide.
Audi’s pilot plant, which is operated in Dresden by German start-up Sunfire, has produced its first batches of the “e-diesel” fuel earlier this month.
To commemorate the potentially huge accomplishment, German Federal Minister of Education and Research Johanna Wanka put a few liters of the fuel in her work car, an Audi A8. (Scroll down for the video.)
1. The first diesel made from air and water (photo: Audi).
The start-up is referring to its base fuel as “blue crude”. It is made by taking electricity from renewable sources — wind, solar or hydro power — and using reversible electrolysis to produce hydrogen from water.
In the next step, the hydrogen is mixed with CO2 which has been converted into CO via two chemical processes. The resulting reactions produce a liquid containing long-chain hydrocarbons — that is the “blue crude”, which is then refined to produce synthetic e-diesel.
According to Audi, most of the carbon dioxide used in the process is supplied by a biogas facility, with some CO2 captured directly from the air, taking the greenhouse gas out of the atmosphere in the process.