Audi E-benzin (E-gasoline) is essentially liquid isooctane, which is currently being produced from biomass. In the first process step, Global Bioenergies S.A. produces gaseous isobutene (C4H8) in a demonstration plant. The Fraunhofer Center for Chemical Biotechnological Processes (CBP) in Leuna, Germany, then adds hydrogen to convert it into sulphur- and benzene-free isooctane (C8H18), which burns with very low emissions.
"Like all Audi E-fuels, the new fuel has many advantages. It isn’t dependent on crude oil, it is compatible with the existing infrastructure and it offers the prospect of a closed carbon cycleE, says Reiner Mangold, Head of Sustainable Product Development at Audi. It was now possible to produce a significant amount of this high-purity synthetic fuel for the first time. These 60 litres will now be examined in a test engine. Thanks to E-benzin’s excellent anti-knock properties, Audi assumes that future, higher-compression engines will be able to achieve further efficiency gains. It is planned to produce the fuel without using biomass in the medium term. Water and carbon dioxide will then suffice.