Gasoline and Other Motor Fuels

Gasoline and Other Motor Fuels. Albert M. Hochhauser (Exxon Research and Engineering Co.). Gasoline and other motor fuels comprise the largest single use of energy in the U.S. The cost of this energy continues to be a primary factor in the national economy. The fraction of resources from which these fuels come that is provided by foreign sources is a matter of political concern. Rapid increases in the price of crude oil has led to programs for developing alternative sources of fuels such as coal, oil shale, and natural gas. Alternative fuels are more important for the potential to reduce emissions and improve air quality than for energy self-sufficiency. All motor fuels in the U.S. are manufactured by private companies. Many participate in other aspects such as refining or marketing. Gasoline demand is determined by the numbers of cars, paved roads, population, and economic growth. Predictions for future demand are somewhat divided. Gasoline must meet exacting specifications and vary according to location, temperature and altitudes at which the product is used. Octane is probably the single most recognized measure of gasoline quality. Petroleum refining begins with distillation of crude oil into many fractions. Most gasoline in the U.S. is obtained by catalytic cracking. Reforming increases octane. Gasoline additives (e.g., dyes, antioxidants, detergents, etc.) are used to improve performance. Stricter emission standards have resulted in changes in vehicle hardware. Diesel fuel, second to gasoline, is used in a wide variety of engines. The ability of diesel fuel to burn properly is described by its cetene number. Diesel manufacturers have found it difficult to meet emission standards Alternative fuels include those made from coal and shale, methanol, compressed natural gas and liquefied petroleum gas. Use of alternative fuels has been promoted for two reasons: potential emissions benefits and reduced dependence on imported petroleum. Keywords: Gasoline; Requirements; Octane; Volatility; Cleanliness; Additives; Blending; Distribution; Fuel economy; Emissions; Diesel fuel; Environmental regulations; Natural gas; Liquefied petroleum gas; Methanol