Ethanol and the Environment

Reduction of Exhaust Emissions  Ethanol burns cleaner and is more efficient than gasoline – reducing carbon monoxide released into the atmosphere

Exhaust  Ethanol contains oxygen which provides a cleaner burn  Gasoline contains many hydrocarbons, some of which are known to be cancer causing agents

 The release of hydrocarbons results in smog  The following pictures were taken from the same angle in Mexico City showing effects of smog No SmogLow SmogHigh Smog

Exhaust  These hydrocarbons are released into the atmosphere through exhaust and when refueling the vehicle  The release of hydrocarbons is greatly reduced when ethanol is mixed with the gasoline

Ozone Pollution  According to the American Coalition for ethanol: “Ozone is formed in air when hydrocarbons, carbon monoxide or nitrogen oxides react in the presence of sunlight and heat”.  “Ground level ozone causes human respiratory stress, and damages many plants, significantly reducing farm crop yields and the "health" of trees and other vegetation”.

Ozone  The ozone production when burning ethanol is less than the ozone released when burning gasoline

Aldehyde Emission  Ethanol combustion does increase aldehyde emission  Some forms of aldehydes are suspected to be cancer causing  Catalytic converters on cars are designed to reduce aldehyde emission

Carbon Monoxide (CO)  A colorless, odorless, toxic gas formed as a product of incomplete combustion of carbon.  Using ethanol-blended fuels will reduce the amount of CO released into the air.

Carbon Dioxide (CO 2 )  A heavy, colorless gas that does not support combustion  Excess carbon dioxide may contribute to global warming  Ethanol combustion results in near zero net CO 2 production because the gas that is released is offset by the gas that is consumed by plants grown for ethanol production

Carbon Dioxide

References  Argonne National Laboratory, Transportation Technology R&D Center