Coke from coal
From Conservapedia
Coke is made by heating coal in the absence of air. The volatile components of the coal are driven off as a gas and the remaining solid is coke. The steel industry is a major consumer of coke. Coke was formerly made in "beehive ovens" and the gas was wasted. [1] [2] Modern coking plants recover the volatile components which can be separated into coal tar and coal gas.
Petroleum coke
Petroleum coke is a similar material obtained as a by-product of the "cracking" of petroleum. [3]
