There are both great advantages and great disadvantages associated with the use of ethanol as an alternative fuel to petroleum.
- Unlike petroleum, ethanol is a renewable resource
- Ethanol burns more cleanly in air than petroleum, producing less carbon (soot) and carbon monoxide
- The use of ethanol as opposed to petroleum could reduce carbon dioxide emissions, provided that a renewable energy resource was used to produce crops required to obtain ethanol and to distil fermented ethanol
- Ethanol has a lower heat of combustion (per mole, per unit of volume, and per unit of mass) that petroleum
- Large amounts of arable land are required to produce the crops required to obtain ethanol, leading to problems such as soil erosion, deforestation, fertiliser run-off and salinity
- Major environmental problems would arise out of the disposal of waste fermentation liquors.
- Typical current engines would require modification to use high concentrations of ethanol
A dual-fuel gas station (ethanol and petroleum) in Sao Paulo, Brazil