Refining

Petroleum or oil refining is the complex, infrastructure-dependent industrial process of dividing and converting crude oil and its constituent compounds and chemicals into marketable petroleum products like asphalt base, tar, other bituminous materials, diesel fuel, gasoline, paraffin wax, kerosene, jet fuel, olefins or alkenes (for plastics manufacturing) and aromatic petrochemicals. Refining requires significant amounts of energy in order to transform streams of crude oil and other additives like chemicals and waste fats and oils into end products, and consequently derives some of its energy from the combustion of crude oil and its products for power generation, or through nearby turbines and utility-scale power generation equipment.

Refineries, the site of petroleum refining, is overwhelmingly concentrated in areas where shipping tankers can supply crude oil and load petroleum products for export and distribution. Refineries are also commonly connected to each other and to sites of production through pipelines in order to minimize logistics and energy costs for transporting low-cost, non-value-added crude oil.

The role of refining in producing consumable and useful petroleum products has led to the overwhelming location of refineries in countries with high consumption markets for petroleum products. Common examples include the United States – with many refineries on the California coast and the U.S. Gulf Coast (located near major consumption markets and accessible to produced crude oil volumes). Other refineries are located close to oilfields, as is the case with heavy oil and oil sands (bitumen) refining, as the heavy produced materials are costly to ship longer distances.