Hydroprocessing is a group of Catalytic Refinery Processes employing Hydrogen in Hydrogenation, Hydrotreating, Hydrocracking or Hydrodealkylation reactions to either remove Hetero Atoms such as Sulfur, Nitrogen, Oxygen, or Metals, to partially Hydrogenate Alkynes, to Saturate Olefins and Aromatics, to break Carbon-Carbon bonds, and to reduce Molecular Weight of Hydrocarbon fractions.