Ethanol is the dominant biocomponent in the gasoline market. Edible ethanol is produced by fermentation of sugar-containing feedstock. Production of fuel ethanol from cellulosic feedstock is under commercialization phase. Industrial ethanol can be produced from petrochemical ethylene by the acid-catalyzed hydration, but this cannot be used to meet bioenergy obligations. Ethanol is a monomolecular compound with narrow boiling point, whereas gasoline consists of hundreds of different hydrocarbon molecules. Ethanol is aromatic-, olefin- and sulfur-free compound. Oxygen content of ethanol is 35%.
- Ethanol for otto engines:
- Ethanol as low concentration “E10” fuel to be used in conventional gasoline cars.
- Fuel ethers. Ethanol can be converted into e.g. ETBE, to be used in conventional gasoline cars.
- E85 fuel containing up to 85% ethanol in gasoline for special flexible-fuel vehicles (FFV).
- Ethanol for diesel engines:
- Fatty Acid Ethanol Esters (FAEE) Ethanol can be converted into FAEE for low level diesel blending.
- Diesel engines for ethanol. Ethanol utilization in compression-ignition requires special engines and/or changes in fuel, such as “Etamax D concept”.
- Note: Ethanol as blending component in diesel fuel is not recommended for safety resons. However, IEA-AMF Task 46 (Schramm, J. Ed. 2016) points out the reduced particle emissions with this concept. Ethanol blending in diesel is also part of IEA-AMF Task 10.