Fuels: name the process—coal strongly heated for 42–48 hours in a closed vessel without air Identify the standard term for this process used to produce coke and by-products.

Concept/Approach

• Prolonged heating of coal in absence of air in a retort/oven produces coke, tar, gas, etc.; this is called carbonization (also termed destructive distillation).

Final AnswerCarbonization (destructive distillation) of coal