Petroleum - oil - refining processes explained

Petroleum refining processes explained

How crude oil is refined into petroleum products
Petroleum refineries convert (refine) crude oil into petroleum products for use as fuels for transportation, heating, paving roads, and generating electricity and as feedstocks for making chemicals.

Refining breaks crude oil down into its various components, which are then selectively reconfigured into new products. Petroleum refineries are complex and expensive industrial facilities. All refineries have three basic steps:
Separation
Conversion
Treatment
Separation
Modern separation involves piping crude oil through hot furnaces. The resulting liquids and vapors are discharged into distillation units. All refineries have atmospheric distillation units, but more complex refineries may have vacuum distillation units.

https://www.eia.gov/energyexplained/oil-and-petroleum-products/refining-crude-oil-the-refining-process.php