Petroleum coke, abbreviated coke or petcoke, is a final carbon-rich solid material that derives from oil refining, and is one type of the group of fuels referred to as cokes. Petcoke is the coke that, in particular, derives from a final cracking processâa thermo-based chemical engineering process that splits long chain hydrocarbons of petroleum into shorter chainsâthat takes place in units termed coker units. (Other types of coke are derived from coal.) Stated succinctly, coke is the âcarbonization product of high-boiling hydrocarbon fractions obtained in petroleum processing (heavy residues)â. Petcoke is also produced in the production of synthetic crude oil (syncrude) from bitumen extracted from Canadaâs oil sands and from Venezuelaâs Orinoco oil sands.