Audi widens e-fuel production for CO2-neutral mobility

November 09, 2017 // By Christoph Hammerschmidt
Renewable energy - this is not only electricity from wind, hydroelectricity and solar radiation. What is produced from this can also fall under the term renewable energy. For example, e-fuels. Car manufacturer Audi, is already involved in this technology. Now he is expanding these activities.

For several years already, Audi has been researching CO2-based but climate-friendly fuels such as e-gas, e-petrol or the synthetically produced e-diesel. The company is now taking the next step in e-diesel production. In a project in Laufenburg (Switzerland), the company intends to use a new technology to make the production of e-diesel in compact units more efficient and thus more economical. The pilot plant also offers the possibility of sector coupling, i. e. a combination of the energy sectors electricity, heat and mobility, and makes renewable energy storable.

E-diesel has the potential to operate conventional internal combustion engines almost without CO2 emission. The power-to-liquid plant transforms excess electricity from hydropower into synthetic fuel. This works according to a chemical principle: the green electricity produced locally in a hydroelectric power plant generates hydrogen and oxygen from water by electrolysis. In the next step, the hydrogen reacts with CO2, using a compact new micro process technology. The CO2 can be extracted from the air or from biogenic exhaust gases and is the only source of carbon in this production context. Long-chain hydrocarbon compounds are formed. These are separated in the final process step; one of the end products is e-diesel, a synthetic diesel fuel that can drive existing combustion engines.