petroleumraffinage

Petroleum refining, or petroleum raffinage, is the industrial process of converting crude oil into usable products such as fuels, lubricants, and chemical feedstocks. It combines separation, conversion, and purification steps to produce streams that meet technical and environmental specifications. The exact product slate depends on crude quality, regional demand, and regulatory constraints. Refineries operate with multiple processing units in an integrated plant.

Crude oil is first conditioned by desalting and heating, then subjected to atmospheric distillation to separate fractions by boiling point. Heavier fractions are sent to vacuum distillation for further separation. The distillation products include naphtha, kerosene, diesel, gas oils, and asphaltic residues, which are routed to downstream upgrading units.

Conversion and upgrading processes reshape molecules and improve quality. Catalytic cracking and hydrocracking convert heavy fractions into lighter fuels and olefins. Reforming increases gasoline octane and yields aromatics. Isomerization and alkylation optimize light fractions for fuel quality. Hydrotreating and desulfurization remove sulfur, nitrogen, and metals to meet product specs and protect catalysts.

Refining produces a range of outputs: transportation fuels (gasoline, diesel, jet fuel), liquefied petroleum gas (LPG), naphtha, lubricants, waxes, and asphalt. Some streams serve as petrochemical feedstocks for ethylene, propylene, and aromatics. By-products such as sulfur are recovered and sold or used in other industries.

Historically, refining advanced rapidly in the 20th century with catalytic cracking, reforming, and hydroprocessing. Modern refineries are highly integrated, with units for hydrogen production, sulfur recovery, and petrochemical processing. Environmental and safety concerns focus on emissions, water management, energy efficiency, and handling of hazardous materials.