Why are carbon and its compounds used as fuels for most applications?

Most carbon compounds that are used for fuels belong to the category of "organic" compounds called "hydrocarbons (HCs)," which, historically, at least, are plentiful and harvested from ancient petroleum deposits by the big oil companies - the raw oil being easily fractionated at processing plants to produce a great variety of different organic compounds from the most volatile (gases, such as CH4, methane; C2H6, ethane; C3H8, propane, etc) to an extensive series of progressively higher boiling liquids (C4H10, butane; C5H12, pentane; C6H14, hexane; C7H16, heptane; C8H18, octane; etc. Our gasoline is usually a complex mixture of these hydrocarbons, in the range between 3 and 12 carbons.

They are a traditional favorite for fuels because they can be stored in condensed form and transported long distances via truck or a complex underground system of pipes; and because they burn cleanly in the presence of sufficient oxygen to give only carbon dioxide (CO2, not classified as an organic compound) and water (H2O), each of which may be trapped and recycled in industrial processes. Another big plus for the use of HCs is that all of their reactions in the presence of oxygen are "exothermic"; that is, as they burn heat is always produced, which can be use to heat our homes and provide the energy needed to run our machines, such as our cars and trucks and jets.