Hasan Djadid Assegaff (1431010056) Refining Process. Refining is the manufacture of petroleum products from crude oil. Refining involves two major branches; separation processes and conversion processes. Crude Oil Petroleum products are made from Crude Oil. There are many types of crude oil which come from many different sources around the world. Disillaion The first stage of crude processing is known as distillation or fractionation and occurs in a column known as a !istillation Column. "n this process the crude oil which is a mi#ture of many types of hydrocarbons is boiled and recondensed to separate the crude oil into components based on ranges of boiling points. H!dro"rocessing