Oil refining is the title for a number of processes from chemical engineering, which remodel crude oil into helpful products equivalent to totally different fuel oils, Liquefied petroleum gas, gasoline, kerosene or diesel oil. These transformation happen in plants called petroleum refineries. The transformations are finished in lots of steps. The refineries are giant industrial complexes, which have many various sub-models, and services. Every refinery has its personal unique arrangement and combination of refining processes. The precise setup of the refinery is basically determined by the its location, desired products and economic issues.