Petroleum coke is a byproduct of petroleum refining, useful in the production of electrodes used as carbon anodes for the aluminum industry, graphite electrodes for steel making, as fuel in the firing of solid fuel boilers used to generate electricity, and as a fuel for cement kilns. Petroleum coke is a by-product of the coker process in the oil industry. In its raw form, it is also called â??green cokeâ?? or green petroleum coke. Calcined petroleum coke is an important industrial commodity that links the oil and the metallurgical industries as it provides a source of carbon for various metallurgical applications including the manufacture of anodes for the aluminum pot liners and for graphite electrodes.