Crude oil and natural gas are complex chemical mixtures that are generally unsuitable for direct use. Oil refining and gas processing turn these mixtures into a wide range of fuels and other products while removing low-value and polluting components.
Refining and processing have both positive and negative environmental impacts: although they remove harmful pollutants and produce cleaner-burning fuels, the operations at refineries and processing plants may release harmful pollutants into the environment, affecting local air and water quality.
processing crude oil is the distillation or separation process. Heat is applied to crude oil so it can be broken down into various components, such as naphtha (used in gasoline), raw kerosene, raw diesel, and fuel oil. Lighter components such as naphtha, which are easier to boil, are collected in the upper part of the distillation column while the heavier components, such as fuel oil, accumulates at the bottom.