Petroleum: The Transport Fuel
Almost all transportation modes depend on a form of the internal combustion engine, with the two most salient technologies being the diesel engine and the gas turbine, since they are the lynchpin of globalization. While ship and truck engines are adaptations of the diesel engine, jet engines are an adaptation of the gas turbine. Transportation is almost completely reliant (95%) upon petroleum products with the exception of railways using electrical power. While the use of petroleum for other economic sectors, such as industrial and electricity generation, has remained relatively stable, the growth in oil demand is mainly attributed to the growth in transportation demand. What varies is the type and the quality of petroleum derived fuel being used. While maritime transportation relies on low quality bunker fuel, air transportation requires a specialized fuel with additives.
It is worth having a closer look at the chemical combustion principle of hydrocarbons. For the majority of internal combustion engines, gasoline (C8H18; four strokes Otto-cycle engines) serves as fuel, but other sources like methane (CH4; gas turbines), diesel (mostly trucks), bunker fuel (for ships) and kerosene (turbofans of jet planes) are used.