Petroleum coke

The vacuum residue of petroleum is cracked and coked at 500-550℃ through the coking unit to produce black solid coke. It is generally considered to be an amorphous carbon body, or a highly aromatized polymer carbide, a carbon body with needle-like or granular structure containing tiny graphite crystals. The hydrocarbon ratio is very high, 18-24. The relative density is 0.9-1.1, the ash content is 0.1%-1.2%, and the volatile matter is 3%-16%.

Petroleum coke (Petroleumcoke) is a product of crude oil that is distilled to separate light and heavy oils, and then the heavy oil is converted into a product through the process of thermal cracking. From the appearance, the coke is black lumps with irregular shapes and different sizes. (Or particles), with metallic luster, coke particles have a porous structure, the main element is carbon, occupying more than 80%, containing 1.5%-8% hydrogen, and the rest are oxygen, nitrogen, sulfur and metal elements. [2-3]

Petroleum coke belongs to the category of easily graphitized carbon. Compared with metallurgical coke, the crystallites of petroleum coke are more neatly stacked between the carbon grid flakes, and the distance between the flakes is smaller; at the high temperature of graphitization, The average thickness (Lc) and average width (La) of the crystal grains of the carbon grid flakes increase, and the inter-layer spacing (d) of the flakes decreases; (Figure 1) the lattice constants (a0 and c0) are close to natural graphite, and the resistance The rate is significantly reduced and the true density is correspondingly increased. Therefore, using petroleum coke as a raw material can make graphite electrodes with lower resistivity. [4]

Petroleum coke has its unique physical, chemical and mechanical properties. The non-volatile carbon, volatile matter and mineral impurities (sulfur, metal compounds, water, ash, etc.) in the heating part determine the chemical properties of the coke. The porosity and density of the physical properties determine the reactivity and thermophysical properties of coke. Particle composition, processing method, hardness, wear resistance, strength and other mechanical properties determine its mechanical properties