The petroleum production, or the petroleum refinery, involves a series of processes to transform the extracted crude oil into useful products.

The crude oil is heated by a furnace and sent to a distillation tower, where it is separated by differentiating boiling points. The material is then converted by heating, pressure or a catalytic reaction into finished products including liquefied petroleum gas, gasoline or petrol, kerosene, jet fuel, diesel oil, fuel oils and specialty products like asphalt and solvents.

The petrochemical processes are responsible for numerous emissions both into the air and into the water. These emissions include fugitive effluents, flue gases from the production process, blowdown systems, emissions and process wastewater that needs to be treated before released into the environment.