The world’s primary energy demand has quadrupled since 1950. Great changes and destructions in the environment have been caused by the combustion of huge amounts of fossil fuels. A reduction of the combustion of fossil fuels can be achieved by saving energy as well as by using renewable energies. Vegetable oil is one representative of the renewable fuels. Today the use of vegetable oils is mainly limited to nutrition and the production of cosmetics and detergents. We are witnessing a renaissance of vegetable oils as lubricating and fuel oils, caused by the search for renewable energies as well as by the surplus on many agricultural markets. Pure vegetable oils cannot be used in most conventional diesel engines. They can be similar in their properties to diesel fuel by means of the esterification process.

Within the next years, several 100 000 tonnes per annum of rapeseed oil methyl ester is to be produced in the European Union. To be able to use raw vegetable oil a fuel in diesel engines, precautions have to be considered to prevent the deposition of oil coke. One of the methods to make the use of vegetable oil in direct-injected diesel engines possible is the “duotherm” method invented by Ludwig Elsbett. The author is convinced that the worldwide first car manufacturer to include vegetable oil engines in his series production will enjoy a great economic success. By using vegetable oil fuels, at least part of the energy supply can be provided in an approximate equilibrium between man and environment.