Coal and Petroleum
Coal
A fossil fuel that formed from the remains of plants that died millions of
years ago. It is a readily combustible rock containing more than 50% by
weight of carbon that produces an amount of energy when heated.
Formation of Coal
Coal is formed as a result of degradation of ancient plant life which
lived millions of years ago. These dead plant matter started to pile up,
eventually forming a substance called peat. Over time, heat and
pressure from geological processes transformed these materials into
coal.
Physical and chemical changes took place as a result of heat and
temperature extracting out all oxygen leaving the plant layers with
carbon-rich content, thus resulting in the formation of coal over a
period of time.
Formation of Coal
Types of Coal
1. Lignite (25-35% carbon) - also called brown coal, is considered the
lowest rank of coal due to its relatively low heat content.
2. Bituminous Coal (35-86% carbon) - is a middle-rank type of coal
containing a tar-like substance called bitumen or asphalt. Its
coloration ranges from black to dark-brown.
3. Anthracite (86-97% carbon) - is a hard, brittle, and black lustrous
coal. It is considered to be the highest ranking coal having the
highest carbon content and energy density of all types of coal.