Fossil fuel embedded energy is still photosynthetic in origin. Terrestrial plants, on the other hand, tended to form coal and methane. Many of the coal fields date to the Carboniferous period of Earth's history. Terrestrial plants also form type III kerogen, a source of natural gas. There is a wide range of organic, or hydrocarbon, compounds in any given fuel mixture. The specific mixture of hydrocarbons gives a fuel its characteristic properties, such as boiling point, melting point, density, viscosity, etc. Some fuels like natural gas, for instance, contain only very low boiling, gaseous components. Others such as gasoline or diesel contain
Ethanol fuel by country since EU-legislation has been passed that requires the fraction of nonmineral origin to become minimum 5.75% of the total fuel consumption volume in 2010. This can be realised by substitutions in diesel or in petrol of any biological source; or fuel sold in the form of pure biofuel. (2007) There are only a few gas stations where E85 is sold, which is an 85% ethanol, 15% petrol mix. Directly neighbouring country Germany is reported to have a much better biofuel infrastructure and offers both E85 and E50. Biofuel is taxed equally as regular fuel. Fuel tanked abroad cannot be taxed