Question

Arrange the types of coal in the decreasing order of energy released by them.

• A. Anthracite
• B. Bituminous
• C. Sub bituminous
• D. Lignite

Answer 1

Lignite is the lowest rank of coal. It has a carbon content of between 60 and 70% on a dry ash-free basis.

Subbituminous coal, also called black lignite, generally dark brown to black coal, intermediate in rank between lignite.

Bituminous is the most abundant rank of coal. It accounts for about 50% of the coal.

Anthracite is the highest rank of coal, unlike other types of coal. It has a carbon content of over 87% and highest heating value.