What are fuel ethers?

Fuel ethers (MTBE, ETBE, TAME and TAEE) are efficient fuel components which enable cleaner burning of petrol in engines.  They act as octane boosters to replace unwanted compounds such as metal-organics, aniline and its derivatives, aromatics that have critical technical or toxicological properties.

Oxygenates are blended into petrol in two forms: alcohols or ethers. MTBE (methyl tertiary-butyl ether) and ETBE (Ethyl- tertiary-butyl ether) and are the most commonly used ether oxygenates, followed by TAME (Tertiaryamyl -methyl ether). European fuel specifications allow them to be blended into petrol in any proportion up to 22% v/v.

Ethers can be both bio-based (e.g. bio-ETBE produced with bio-ethanol) and non-bio-based. The technical properties when used in fuels do not change.

Further reading: Ethers