Fuel classification used in power generation In fuel technology, the term “steam coal” (used for raising steam in boilers) generally refers to which type of coal?

Introduction / Context:
Coal terminology can be confusing because it mixes rank (lignite, sub-bituminous, bituminous, anthracite), coking properties (coking vs. non-coking), and form (lump vs. pulverised). “Steam coal” is a commercial term commonly used in power generation markets to denote fuels intended for steam-raising in boilers.

Given Data / Assumptions:

• Steam coal is sold primarily for boiler firing to generate steam and electricity.
• Emphasis is on calorific value, ash, volatile matter, and non-coking behavior.
• Coking properties are not required for power boilers.

Concept / Approach:
Steam coal is typically non-coking bituminous coal selected for combustion characteristics rather than metallurgical coke production. Pulverisation is a preparation method applied to many ranks and is not a distinct coal type. Brown coal (lignite) is lower rank with higher moisture and often termed “lignite,” not “steam coal” in strict trade usage, although it can be used in power stations.

Step-by-Step Solution:
Differentiate “rank” (bituminous, lignite, anthracite) from “coking property.”Steam coal is purchased for boilers; coking behavior is unnecessary and often undesirable.Hence, steam coal aligns with non-coking bituminous coal specifications.

Verification / Alternative check:
Power-plant fuel contracts and standards (for example, specifying volatile matter, ash, sulfur, and calorific value) identify non-coking bituminous grades as typical “steam coal.”

Why Other Options Are Wrong:
Pulverised coal (A) is a physical form, not a coal rank/type. Brown coal (B) is lignite and usually named as such. Coking bituminous (C) is reserved for metallurgical coking. Anthracite (E) is a distinct high-rank fuel and not commonly called steam coal in trade.

Common Pitfalls:
Equating “pulverised coal” with a coal type; conflating coking and non-coking uses.

Final Answer:
Non-coking bituminous coal used for thermal power (steam-raising)