The world's coal reserves are estimated in trillions of metric tons, which means there is enough coal fuel for everyone for a long time. It is projected that the coal industry can sustain and thrive throughout the next century. In other words, fossil coal fuel should last us for the next 400 years. In comparison, oil reserves are expected to last for 40 years, and natural gas for 60 years. Currently, coal accounts for 28% of the total energy produced worldwide.
In the ecosystem of peatlands, plants that grow over time become compacted, hardened, and subjected to high temperatures. The biomass of these plants gradually transforms into peat, which later turns into coal through a process of coalification. This occurred during the Carboniferous period. The peat layer transformed into lignite or brown coal, and heat and pressure further transformed it into bituminous coal and anthracite. For example, a 20-meter peat layer over time becomes a 4-meter layer of brown coal.
Coal fuel is composed of approximately 90% carbon, hydrogen, oxygen, sulfur, nitrogen, and trace amounts of minerals, which, when coal is burned, contribute to the formation of ash. The minerals contain sulfides, which, when coal is burned, produce sulfur dioxide, a significant source of atmospheric pollution. The density of coal fuel ranges from 1280 to 1500 kg/m3, and its calorific value ranges from 7290 kcal/kg to 8800 kcal/kg. The value of coal fuel is determined by its combustibility and coking properties. Based on the degree of metamorphism, coal is classified into sub-bituminous coal (65-70% carbon), bituminous coal (over 75% carbon), and anthracite (up to 95% carbon).
The countries with the highest coal production, where coal mining does not require significant expenses, are Australia, the United States, Russia, and Canada. The largest importers of coal fuel are Japan, South Korea, and Western European countries. The most favorable source of coal imports for Western European countries is Poland. The largest coal basins are the Huanghe Basin (China), Appalachian Basin (USA), Ruhr Basin (Germany), Donets Basin (Ukraine), Upper Silesian Basin (Poland), Minusinsk Basin (Russia), and South Wales Basin (United Kingdom).
Coal fuel is one of the oldest, most reliable, and cost-effective types of fuel. Traditionally, it is used for heating various spaces. However, it is also widely used for electricity generation. About 40% of the world's coal production is consumed for electricity generation. In the process of generating electricity, coal is pulverized and burned, and the resulting heat converts water into steam, which drives electricity-generating turbines. Coal fuel is also used in the production of combustible gases, diesel fuel, and gasoline. Coal fuel has a longer burning time and higher energy content compared to wood pellets, providing up to 50% more heat.
