The petroleum refinery is an industrial facility where crude oil is subjected to various processes for the production of commercial derivatives. Such facilities deal with energy consumption, personnel management and equipment maintenance, among others. In every oil refinery, separation, conversion and treatment take place. The objective of the oil refinery is the production of high value-added products such as LPG, jet fuel, gasoline, and others. By means of the knowledge of applied chemistry, the present study was carried out to know the structural basis of the main organic compounds present in each purified fraction, taking into account several reactors and complementary processes within a refinery.