Understanding Coal Energy, Types, and Uses in Industry

Coal is one of the fossil fuels with a significant role in various industries. Coal energy is widely used in manufacturing processes, including power generation and as fuel.

This article discusses the use of coal energy in the industry and the types. To get a better understanding, learn the complete information below.

What Is Coal?

Coal energy is derived from combusting coal, a solid material rich in carbon and hydrocarbons. 50% of coal's weight contains carbonaceous substances from the process of plant fossils hardening and solidifying.

Coal is one of the fuels that humans have used for a long time, even before the modern industrial era. This material formed over centuries through the compaction and heating of dead plants in oxygen-deprived environments (such as swamps).

Due to the lack of oxygen, the plants did not decompose easily. As a result, anaerobic bacteria converted them into a simpler substance: carbon. Continuous heat and pressure over millions of years transformed this organic matter into a rock-hard, flammable substance rich in carbon. Researchers believe that most of the world’s coal formed during the Carboniferous Period, approximately 300 million years ago.

Since the Industrial Revolution, coal has been widely used for various purposes. In fact, even today, coal consumption continues to rise every year. The International Energy Agency (IEA) reports that global coal energy demand rose by 1.2% in 2024, or approximately 67 million metric tons of coal equivalent (Mtce). The largest share of demand came from the electricity sector, accounting for two-thirds of global consumption.

In 2024, the world’s three largest coal-producing countries (China, India, and Indonesia) set new records. According to the International Energy Agency, China, which accounts for half of the world’s coal supply, saw a 1% increase in production.

Then, India was predicted to see production increase by up to 7% at that time, while Indonesia was forecast to produce more than 800 Mt of coal for the first time.

Types of Coal

In general, coal is categorized by its carbon content and the thermal energy it can generate. Here is the complete information:

Anthracite: High-quality coal containing 86–97% carbon. This type of coal has the highest heat value among all types.
Bituminous: It is usually utilized for power generation and as a fuel in the steel and iron industries. Bituminous coal contains 45–86% carbon.
Sub-bituminous: It contains 35–45% carbon and has a lower heat value than bituminous coal.
Lignite: It contains 25–35% carbon and has the lowest heat value among all types. These coal deposits are “younger” and have not been subjected to extreme pressure or heat. Lignite coal has a high moisture content and is brittle.

Moreover, coal can be classified based on the macroscopic appearance. There are four main types, including:

Vitrain: Vitrain coal is characterized by a black luster; it is brittle and easily breaks into angular fragments. Vitrain is composed of vitrinite macerals derived from the woody tissue of large plants. It is believed to have formed under relatively dry surface conditions.
Durain: This coal has a granular texture. It contains liptinite, inertinite, and numerous inorganic minerals. Generally, durain ranges in color from dull black to dark gray. Durain is believed to have formed in peat deposits below the water’s surface.
Clarain: It has alternating thin layers of bright black and dull black. Typically, the lightest layers consist mostly of vitrinite, while the dullest layers contain liptinite and inertinite. The luster of this coal is not as bright as that of vitrain.
Fusain: This coal is soft and easily crumbles into a fine, soot-like powder. Fusain consists mostly of fusinite and semifusinite from the inertinite group. Fusain resembles wood charcoal in appearance. It is believed to have formed in peat deposits affected by forest fires.

For context, macerals are organic particles contained in coal. There are three primary types of macerals: vitrinite, liptinite, and inertinite. Vitrinite generally comes from wood tissue, while liptinite is derived from plant parts with resin or wax, such as spores and cuticles. Then, inertinite is derived from degraded or changed parts of plants during peat formation.

Uses of Coal

Coal energy is utilized by various sectors to create massive energy. Below are some of the uses:

1. Power Generation

Coal is the largest energy source for power generation using steam. Coal is combusted inside a boiler to heat water. Then, the steam will move the power plant turbines. The mechanical energy moves the generator and generates electricity.

2. Heavy-duty Industries

Coal is used to produce steel, iron, and cement. Coal heats the furnace in metal smelting and cement drying.

3. Other Industries

Coal energy is used to move machines in the manufacturing industries. Additionally, coal is a carbon source in methanol and ammonia production.

That concludes the information about coal energy. Up to recently, coal has been one of the largest energy sources and plays a very significant role, especially in power generation. However, as a nonrenewable energy, the major challenge is how we use coal more efficiently and sustainably.

Regarding this, Chandra Asri Group, as #YourGrowthPartner, developed refuse-derived fuel (RDF) innovations from waste as a fuel mix for coal boilers in the Puloampel Site Office. RDF accounts for 5% of the total energy requirements of the boiler, with the total volume of waste utilized reaching over 60,000 metric tons.

The RDF co-firing project, which was implemented in July 2025, has been successfully commercialized and has had a positive impact on the environment, with an estimated reduction in carbon emissions equivalent to 29.63 metric tons of CO₂.