Oxygenates improve combustion efficiency, thereby reducing polluting emissions. Many oxygenates also serve as excellent octane enhancers when blended with gasoline. Methanol is an alcohol made from natural gas, biomass or coal. When methanol is blended with gasoline, a co-solvent such as ethanol is required. Methanol is quite corrosive and poisonous.
Methanol is produced primarily as a derivative of natural gas.
MTBE has been found in groundwater in the U.S., and is the cause of significant public concern. ETBE is manufactured from ethanol and isobutylene. The lower volatility of ETBE, relative to other oxygenates, would help reduce the evaporative emissions, but could cause problems with respect to cold starting and driveability. These are petroleum-derived compounds including benzene, xylene and toluene characterized by the benzene ring in their molecular structure. MMT is widely used in Canada as an octane enhancer in lead-free gasoline.