As we get closer to the mass production and marketing of electric cars, automakers continue working hard finding other alternatives to fill the gap between EVs and traditional cars. Audi has been on the forefront of all of this technology with its e-tron and g-tron lines of cars. Now, Audi has a new feather in its alternative-fuel cap, as it has developed a CO2-neutral diesel fuel that it can produce using just water, CO2, and green power.
While the process of turning CO2 back into fuel has been in the works since the 1990s, Audi’s synthetic diesel fuel, known as e-diesel, has been in the works for only the past four months. Despite the short amount of time, it is definitely one of the most successful conversions.
To develop this fuel, Audi and Sunfire use plain old water and CO2, which comes from two sources. The main source of the CO2 is a biogas facility, but a small portion of it is also extracted right from the air.
The process of creating the e-diesel involves converting the water to steam, then using high-temperature electrolysis, the steam is broken down into hydrogen and oxygen. Following separation, the hydrogen reacts with the CO2 under pressure and at high temperatures to produce a liquid made of long-chain hydrocarbon compound. Audi calls this liquid “blue crude.” Audi and Sunfire then refine the blue crude to create the e-diesel fuel, which is free of sulfur and aromatic hydrocarbons.
A big hiccup in the earlier attempts to turn CO2 back into fuel was the energy required to pull the CO2 from the air and separate the hydrogen from the oxygen in water. This electricity alone negated the benefits behind creating this fuel. Well, Audi and Sunfire managed to complete this process in a green facility, so there is no additional carbon footprint in the creation process.
What’s more, the efficiency of the creation process is 70 percent, and the e-diesel ignites easily, making it great for mixing with standard diesel fuel or using it as a fuel in itself.
According to Audi, this e-diesel will, “allow long-distance mobility with virtually no impact on the climate.” I am no chemist, so I will just have to take Audi’s claim at face value here.
The next step for Audi is to complete the production of e-gasoline, Stay tuned and we’ll update you once this process is complete.