Petroleum coke is a mixture of carbon and hydrogen joined by nature in many different ways.
There are many different variations and consistencies of petroleum from which the coke is derived. For example, heavier oil contains more carbon and less hydrogen, while lighter oil has more hydrogen. To separate these mixtures of carbon and hydrogen, crude oils are subjected to a refining process. This is unlike higher-end products such a gasoline. This type of coke is used in the manufacture of electrodes for electric arc steel furnaces.