Direct Positive Effects of Ethers Use
The use of ethers, such as methyl-tert-buthyl-ether (MTBE) and ethyl-tert-buthyl-ether (ETBE) enables a more complete fuel combustion, resulting in direct air quality benefits that include the reduction of specific pollutants limited by law, such as carbon monoxide (CO) and unburned hydrocarbons (HCs), as well as other serious pollutants such as particulate matter (PM) and ground-level ozone (O3).
Studies commissioned by the California Air Resources Board (CARB) and the U.S. Environmental Protection Agency (EPA), two of the world’s leading regulatory agencies, have demonstrated that the use of MTBE, in particular, reduces permeation—a key component of evaporative emissions from a vehicle fleet—compared to both pure gasoline and gasoline blended with ethanol. As a result, the use of MTBE reduces the formation potential of, among other criteria pollutants, ground-level ozone.
Recent studies have confirmed these laboratory findings, showing that lower ethanol use in gasoline has resulted in lower ozone levels in highly-polluted cities such as Rio de Janeiro. Gasoline blended with ethers entails an even lower ozone formation potential than gasoline itself.
Mexico: air quality concerns drive fuel quality considerations