Oil refinery, an industrial process plant where crude oil is processed and refined into useful petroleum products.
Crude oil ,petroleum (from Greek “Petra ”—rock and “oleum ”—oil),sometimes colloquially called black gold, is a thick , dark brown or greenish liquid . A widely believed myth is that the crude oil itself is flammable ,however it is actually the gas that evaporates from the crude oil that is flammable.
Petroleum is an important “primary energy ”source ,and it is also the raw material for many chemical products ,including solvents ,fertilizers ,pesticides ,and plastics etc. In refining , the component chemicals of crude oil are separated by fractional distillation ,which is a separation based on relative boiling points (or equivalently relative volatility ).The different products (in order of b.p.)include light gases (e.g. methane ,ethane ,propane ),gasoline ,jet fuel ,kerosene ,diesel ,gas oil ,paraffin wax ,asphalt ,and so on.
Ctane can also be improved by catalytic reforming ,which strips hydrogen out of hydrocarbons to produce aromatics .which have much higher octane ratings . Intermediate products such as gas oils can even be reprocessed to break a heavy ,long –chained oil into a lighter short –chained one ,by various forms of cracking such as fluid catalytic cracking ,thermal cracking ,and hydrocracking .The final step in gasoline production is the blending of fuels with different octane ratings ,vapor pressures and other properties to meet product specifications.