An Overview of the Technical Implications of Methanol and Ethanol as Highway Motor Vehicle Fuels

The characteristics of methanol and ethanol as highway motor vehicle fuels are contrasted with those of conventional gasolines and diesel fuels. The implications of the physical and chemical differences of these fuels for motor vehicle design and emissions are discussed. Potential material compatibility concerns, such as elastomer swelling and metal corrosion, and safety concerns, such as fire hazard, flame luminosity, and human toxicity are examined. A number of possible air quality impacts are examined including changes in ozone, carbon monoxide, oxides of nitrogen, particulate matter, toxic compounds (benzene, aldehydes, 1,3-butadiene), and global climate “greenhouse” gases (carbon dioxide, methane, nitrous oxide).