Biofuels
Fuels made from plant or animal materials. These fuels are renewable as they can be replenished as they are used.
Burning a biofuel and producing carbon dioxide is not considered increasing the atmospheric carbon dioxide- as it is just recycling it. However, once these fuels are transported and machinery running on fossil fuels is introduced this balance is disrupted.
Types of biofuels
More detailed information Types of fuels