ENERGY

In modern life, the main source of energy comes from the consumption of oil. This name is given to a gaseous, liquid and solid mixture of hydrocarbons, which has been found in deposits of sedimentary rocks, in different proportions and in different places on Earth. In its crude state, oil is practically a substance without any utility; but subjected to a refining process, it provides fuels, lubricants, solvents, coating materials and an innumerable quantity of other products. Starting with petroleum-based fuels, these represent more than half of the energy consumed by the world.