What are the three types of coal?

• A. Lignite, Bituminous, Anthracite
• B. Lignite, Bituminous, Subbituminous
• C. Peat, Lignite, Charcoal
• D. Anthracite, Subbituminous, Peat

Answer: (A)

Coal forms through burial and heating of plant material, creating a spectrum of ranks with increasing carbon content and energy as they mature. The three common coal types at higher maturation are lignite, bituminous, and anthracite.

Lignite is the youngest rank, with more moisture and less carbon, so it has the lowest heating value among coal types. It’s relatively soft and brownish, and while it can be used for electricity, it isn’t as energy-dense as the others.

Bituminous coal sits in the middle, with higher carbon content and energy than lignite. It’s the most widely used type for electricity generation and for steel production, thanks to its strong heating value.

Anthracite is the most mature, with the highest carbon content and the cleanest burn (less smoke) among the coal ranks. It delivers the most energy per unit mass, but it’s less abundant.

Other materials like subbituminous coal, peat (which isn’t coal), and charcoal (a product of pyrolyzed wood) aren’t considered coal types in the same category. So the trio that best represents the major coal types is lignite, bituminous, and anthracite.