If you ask the average American about what coal is and where it comes from, they may just scratch their heads, but when you get down to it, coal is as American as apple pie. It heats your home, it’s in the steel in your car, and the iron that holds together your office building. Coal's there, you just don't know it...yet. So, where does coal actually come from? The black sedimentary rock is a long gestating fossil fuel found beneath the surface of the Earth. Like any good recipe for success, first you mix peat with acidic hypoxic water, then cover with sediment, and cook on high heat for, oh, 100 million years! This arduous process was known as coalification, but that's all history, and you might be wondering, "Where does coal come from today, and how does it affect me as a consumer?"
Coal provides more than half of the electricity in the United States, and more than one quarter of its global reserves sits under American soil. In fact, this organic rock is so powerful that U.S. coal resources have a higher total energy content than ALL of the world's known recoverable oil. The downside: like most fossil fuels, it’s not easy to get to, plus transportation of the fuel is astoundingly difficult. Some of the oldest coal reserves in the U.S. can be found in the Appalachian Mountains, specifically in West Virginia, where Coal will be taking place. That’s where it comes from, now where does it go?
Coal refining is nowhere near as complex as oil refining. The rocks are washed with a water or chemical bath to remove impurities, and after that, are pulverized into a heavy powder at the power plant just before being burned. In the most common type of coal plant, pulverized coal is blown into the furnace where it burns while airborne which heats water that’s flowing through tubes running through a furnace. Once the water is heated to its boiling point, the pressurized steam then blasts through a turbine, which turns a generator to produce electricity. After the steam has passed through the turbine, it is condensed into water and cooled, and sent back into the furnace. This cycle is known to engineers as the Rankine Cycle, and is similar to the process that is used in nuclear power plants.
More recently, coal has mainly been used to generate electricity since it is a reliable and low cost energy source. In addition to electricity, coal is used by manufacturing plants and industries to make paper, chemicals, metal products, plastics, ceramics, fertilizers, and tar. Most specifically in terms of alternative uses, coal is used for producing coke (no, not the soft drink). Coke is a high carbon fuel that’s primarily used in the steel industry for metal processing. In addition to its use as coke, there are other coal-derived compounds and residues that are used in a wide range of manufacturing processes including synthetic rubber, fiber, insecticides, paints, medicines, and solvents.
This is the first in an ongoing series of articles about the importance of coal and coal miners. We’ll have more great videos and articles about the importance and danger of coal mining in the weeks leading up to the series premiere of Coal on Wednesday, March 30 at 10PM/9C. Don't forget to RSVP for the season premiere and like Coal on Facebook.