Petroleum coke, abbreviated coke or petcoke, is a final carbon-rich solid material derived from petroleum refining and is a type of fuel group called colas. Petcoke is coke specifically derived from a final. The cracking process - a thermo-based chemical engineering process that breaks down oil's long-chain hydrocarbons into shorter chains - takes place in units called koker units. (Other types are coal derived from cola.) Simply put, coke is "the carbonization product of high boiling hydrocarbon fractions (heavy residues) obtained in oil processing". Petcoke is also a synthetic crude oil (syncrude) pitch extracted from Canada's oil sands and Venezuela's Orinoco oil sands.

Processes using distillation of residual oils in petroleum coke units Petroleum refining is processed at high temperature and pressure leaving the petcoke after removing gases and volatiles and separating the remaining light and heavy oils. These processes are referred to as "coking processes" and are most typically chemical engineering plant processes for a particular process delayed coking.