The primary energy consumption in the world has increased continuously. The most important primary energy source is oil. The supply of automotive fuels today is based almost entirely on oil, and the demand for liquid transportation fuels worldwide will rise significantly in the next fifty years. Growing energy consumption and decreasing fossil resources are reasons for increasing prices of fossil fuel. Besides limited availability, contribution to greenhouse effect and pollutant emission represent another problem of fossil fuel. Both of these problems can be overcome by increased application of renewable biofuels. Therefore, great effort is made to supplement the primary energy sources by including renewable energies. There are alternative fuels 1st and 2nd generation. Some of them show high potential for reduction of engine out emission. But there are economical and technical barriers when such fuels are applied. This paper shows both advantage and disadvantage of alternative fuels, especially when used for diesel engines.

alternative fuels; automotive industry; diesel engine