Coke is a material with high carbon content and porosity. It has high resistance to breakage and low reactivity with gases, particularly CO2. Coke production is an important part of the integrated iron and steel plants, as it is used both as a reducing agent and as a source of thermal energy in blast furnace.
Coke is produced by heating coking coals up to 1000 to 1200 °C for several hours in coke ovens to drive off volatile compounds and moisture. Coal characteristics play an important role on the coke consumption and thus the energy demand. A 1% increase in the ash content of coke may increase the coke demand by 2%. This is an important factor for countries like India where the coal ash content is high.