Inventors of early automobiles like Henry Ford and Rudolf Diesel in the late 1800s and early 1900s expected that the engines of their cars would run on fuels derived from plants, but then cheap petroleum became popular. So the cars that were used by the general public ran on gas.
Nowadays, with rising oil prices and growing ecological awareness, biofuels are more and more in demand and will be replacing petroleum as a source of power for cars, trucks, and aircraft in the future. Biofuels are made from plants and vegetable oils and other things that grow in nature. So they are renewable sources of energy.
Biofuels produce less carbon dioxide than petroleum fuels, and therefore they do not contribute as much to global warming. They also produce fewer toxins, which contribute to respiratory diseases in people in many cities. While nature takes billions of years to make oil,biofuel in limited only by growth rates of plants and the availability of farmland. Biodiesel and ethanol are two types of biofuels.