Coke Oven Gas (COG), also known as coke oven gas, is a type of high-calorific-value gas, crude gas or raw gas due to its high content of combustible components. It refers to a flammable gas produced during the high-temperature dry distillation of a blend of bituminous coals prepared for coking in a coke oven, while producing coke and tar products, and is a by-product of the coking industry. Coke oven gas is a mixture, and its yield and composition vary depending on the quality of coking coal and the conditions of the coking process. Generally, 300–350 cubic meters (under standard conditions) of coke oven gas can be produced per ton of dry coal, with a calorific value of approximately 17.3854 MJ per standard cubic meter.