ABSTRACT
Hydrofining and hydrotreating are processes in which selected petroleum fractions react with hydrogen in the presence of monofunctional catalysts: metallic sulfides or oxides. The purpose of hydrofining is the elimination of the heteroatoms by means of hydrogenolysis reactions. In hydrotreating, which uses more severe operating con ditions and more active catalysts, the polycylic aromatic hydrocarbons also undergo a partial hydrogenation.
