Black Power: The Force of Coal

In the third installment of the power series, the topic is coal. I will briefly describe the origin of coal and a couple common types. I shall then go into the uses of coal. Finally, I will discuss the problems associated with the material. As with the discussion of natural gas, my main source for this article is the book Beyond Oil.

(Coal)

Coal, like other fossil fuels, is formed from organic materials. However, unlike oil and gas, which form from the decomposition of said materials, coal is formed in an entirely different manner. Coal was formed mainly during was has been termed the "Carboniferous period," which was approximately 280-310 million years ago. However, there are coal beds that are both younger and older than the Carboniferous period.

Basically, the period was a cycle of flooding as the glaciers would melt and the sea level would rise. The rise in sea level would bury bogs and swamps, areas of significant botanical accumulation. Layers of soil and fossils would be deposited on top of the area and "baked" (for lack of a better term). The materials used in coal production, not just the temperature, helped determine the type of coal that resulted. For example, spores and pollen produce a type of coal that burns easily and leaves very little ash (cannel coal). Jet, on the other hand, is a product of wood, and is usually glossy black. It can be used in jewelry.

Coal is further categorized by age. It ranges from liginte (jet) to bituminous to anthracite. Each new category has a greater percentage of carbon. Anthracite, the last of the line, is over 90% carbon. It can be ignited for use in industrial heating. The most commonly used coal, however, is bituminous. It is used both for producing electricity and something called coke. Coke is treated coal burned in large ovens to produce charred lumps.

The byproducts of coke can be used for various industries. For example, the gases can be burned for light and heat. Others of the gases can be used as catalysts for other reactions which produce iron from ore. "Coal oils" (hydrocarbons) can be used in lamps. Most interestingly, the tars produced have lead to vibrant synthetic dyes.

The main use for coal, however, is in the generation of electricity. Coal is burned to heat water. The steam created is then used to turn turbines which create electric current. However, this is a major problem with the use of coal. Most coal is impure, containing amounts of sulfur and mercury. Since coal is a hard material, it is difficult to remove the impurities in that form. And while the smoke can be scrubbed, but it is still difficult. Since the main byproduct of burned coal is CO2, that creates a problem with "greenhouse gases." Despite these problems, there are a lot of coal burning plants in the United States. Another major issue with coal burning is sulfur dioxide (SO2). In the atmosphere, sulfur dioxide becomes sulfuric acid. That, in turn, becomes a contributor to acid rain and smog. Other coal issues include mercury pollution, underground mind drainage, and major surface disruptions caused by open-pit mines.
Despite this, coal is the best source of energy. It is the cheapest per unit of energy. It is also quite an industry. The US is one of the major producers of coal worldwide. There are over 6000 coal mines in the US alone. The former Soviet Union is also a major producer of coal. And coal reserves are large enough that, at the rate it is being mined, production should be able to continue for a few hundred years.

So, the problem is, do we continue using coal? Do we continue burning coal, producing greenhouse gases and acid rain? Or do we look for alternate sources of energy, which is inevitable anyway?