Petroleum coke is a product transformed into heavy oil by the process of thermal cracking after the separation of light and heavy oil by distillation of crude oil. From the appearance, coke is a black block (or particle) with irregular shape and different size, and has metallic luster. The particle of coke has multi-pore structure, and the main element composition is carbon.Occupy 80wt%(WT is abbreviation of Weight is the meaning of Weight percentage.5WT% is equivalent to 50,000 parts per million (PPM is in millions).), and the rest are hydrogen, oxygen, nitrogen, sulfur and metallic elements.Petroleum coke has its unique physical, chemical and mechanical properties, itself is the heating part of the non-volatile carbon, volatiles and mineral impurities (sulfur, metal compounds, water, ash, etc.) these indicators determine the chemical properties of coke.
The morphology of petroleum coke varies with the process, operating conditions and feeding properties.From the production of petroleum coke site are known as coke (green cokes), containing some carbonized volatile hydrocarbon compounds, coke can be used as fuel grade petroleum coke, if you want to do aluminum anode or steel electrode, it needs to be calcined again by high temperature, so that it is completed carbonization, reduce volatile to the minimum degree.The coke produced in most oil coking facilities is a black brown porous solid, irregular lump, which is also known as sponge coke.The second type of petroleum coke with better quality is called needle coke, which is more suitable for electrodes because of its lower resistance and thermal expansion coefficient.The third hard petroleum coke is shot coke, which is pellet shaped and has a small surface area that makes it difficult to coke, so it is not used for much.