Alternative fuels for transportation

There are four alternative fuels that can be relatively easily used in conventional Cl engines: Vegetable oil, bio-diesel, Fischer-Tropsch (F-T), and dimethyl ether (DME). Both F-T and DME can be manufactured from natural gas and are, therefore, not limited by feedstock availability. The main advantage of the diesel engine is that the level of efficiency is greater than in the Otto cycle engine. Gasoline is a blend of hydrocarbons with some contaminants, including sulfur, nitrogen, oxygen, and certain metals. The four major constituent groups of gasoline are olefins, aromatics, paraffins, and napthenes. The main alternative fuels include alcohol, liquefied petroleum gas, compressed natural gas, hydrogen, and electricity for operation gasoline type vehicles.