Due to environmental issues, desulphurization and increasing of aromatic levels is typically done during hydroprocessing. During hydroprocessing the trace materials which are cause natural lubricity to fuels are eliminated as well as Sulphur and aromatic levels. A lack of fuel lubricity due to reduction of sulfur levels in fuel can cause fuel pump wear and engine failure. Consequently, to reach lubricity requirements in accordance with the diesel fuel specification, lubricity improver is required.
