Destructive distillation of Coal

1. destructive distillation. A process by which organic substances such as wood, coal, and oil shale are decomposed by heat in the absence of air and distilled to produce useful products such as coke, charcoal, oils, and gases.
2. https://en.wikipedia.org/wiki/Destructive_distillation
3. http://www.tutorvista.com/content/physics/physics-ii/fission-and-fusion/coal-distillation.php