Coal
Overview
Coal (석탄, 石炭; coal) is a solid combustible sedimentary rock formed when plant matter was buried in strata hundreds of millions of years ago and, over a long period, was subjected to heat and pressure and carbonized. Its main component is carbon, and as the fossil fuel that humanity has used for the longest time and in the greatest quantities since the Industrial Revolution, it serves as a key raw material for the power generation, steelmaking, and cement industries. At the same time, its combustion emits large amounts of carbon dioxide, fine particulate matter, and sulfur oxides, and it is cited as a major cause of climate change and air pollution.
Main content
Formation process and reserves
Coal forms when plant debris that accumulated in swamps millions to hundreds of millions of years ago is covered by water and soil, blocking oxygen supply, and passes through peat and undergoes carbonization. As carbonization progresses, moisture and volatile matter decrease and carbon content increases. Global reserves are estimated at about 1 trillion tons and are concentrated in certain countries such as the United States, Russia, Australia, China, and India. In South Korea, anthracite was distributed in the Taebaek, Jeongseon, and Samcheok areas of Gangwon Province and the Boryeong and Seocheon areas of South Chungcheong Province, but most mines were closed due to worsening economic viability.
Types and grades
According to the degree of carbonization, coal is classified into peat, lignite, sub-bituminous coal, bituminous coal, and anthracite.
- Lignite: Contains much moisture and has a low calorific value, so it is mainly used for power generation.
- Bituminous coal: The most widely used type, divided into coking coal for steelmaking and thermal coal for power generation.
- Anthracite: Has a high carbon content of over 90% and produces little smoke, but is difficult to ignite. South Korea's household briquettes are a representative example.
Mining methods
Open-pit mining is a method of excavating large-scale deposits near the surface, with high productivity and low cost. Underground mining is a method of driving tunnels underground to extract coal seams, and entails safety issues such as gas explosions, ground subsidence, and dust. Recently, automated and remote-controlled equipment and smart mining technologies are being introduced.
Industrial uses
Coal is used as fuel for thermal power generation, as a raw material for coke in steel mill blast furnaces, as fuel for cement calcination, and as a basic raw material for the chemical industry (syngas and methanol). In particular, in the steel industry, coke is essential for reducing iron ore, making it difficult to replace in the short term.
Environmental and social impacts
Coal combustion is the largest single source of carbon dioxide emissions and also emits sulfur oxides, nitrogen oxides, fine particulate matter, mercury, and others. In the mining process, problems such as mine wastewater, waste rock dumps, ground subsidence, and miners' pneumoconiosis (black lung disease) occur. Accordingly, pollution control facilities such as desulfurization and denitrification equipment and dust collectors are mandatory.
Latest trends
As of 2024–2025, global coal demand is being driven by China and India and remains at an all-time high, but the dominant outlook is that it will pass its peak in the long term and enter a gradual decline. The European Union and the United States are rapidly reducing the share of coal power through expanded renewable energy and strengthened carbon pricing, and the United Kingdom closed its last coal power plant in 2024, becoming the first G7 country to completely end coal power. On the other hand, Indonesia, India, China, and others continue to build new coal power plants due to energy security and surging electricity demand. South Korea is also pursuing a phased reduction of coal power in the 2030s and a transition to LNG and renewable energy, and cases of converting closed mining areas to alternative industries such as data centers, hydrogen, and tourism are increasing. Technologically, attempts to decarbonize coal power such as carbon capture and storage (CCS) and ammonia co-firing are underway, but there is significant debate over economic feasibility. Meanwhile, due to the surge in power demand from AI data centers, a rebound phenomenon is also appearing in some countries where coal power generation is temporarily increasing.
Related topics
- [[Fossil fuels]]
- [[Climate change]]
- [[Renewable energy]]
- [[Thermal power generation]]
- [[Steel industry]]
- [[Decarbonization transition]]