Coal plays an essential role in our global energy mix, particularly for power generation, but we need to use it efficiently and reduce its environmental footprint.
In a coal-fired steam station – much like a nuclear station – water is turned into steam, which in turn drives turbine generators to produce electricity. Here’s how the process works.
1. Heat is created
Before the coal is burned, it is pulverized to the fineness of talcum powder. It is then mixed with hot air and blown into the firebox of the boiler. Burning in suspension, the coal/air mixture provides the most complete combustion and maximum heat possible.
2. Water turns to steam
Highly purified water, pumped through pipes inside the boiler, is turned into steam by the heat. The steam reaches temperatures of up to 1,000 degrees Fahrenheit and pressures up to 3,500 pounds per square inch, and is piped to the turbine.
3. Steam turns the turbine
The enormous pressure of the steam pushing against a series of giant blades turns the turbine shaft. The turbine shaft is connected to the shaft of the generator, where magnets spin within wire coils to produce electricity.
4. Steam turns back into water
After doing its work in the turbine, the steam is drawn into a large chamber in the basement of the power plant. In this important step, millions of gallons of cool water from a nearby source (such as a river or lake) are pumped through a network of tubes running through the condenser. The cool water in the tubes converts the steam back into water that can be used over and over again in the plant.
The cooling water is returned to its source without any contamination, and the steam water is returned to the boiler to repeat the cycle.