What Is Coal

An encompassing description of coal has been given by van Krevelen [1], in which he states: "Coal is a rock, a sediment, a conglomerate, a biological fossil, a complex colloidal system, an enigma in solid-state physics and an intriguing object for chemical and physical analyses." In short, coal is a chemically and physically heterogeneous, "combustible," sedimentary rock consisting of both organic and inorganic material. Organically, coal consists primarily of carbon, hydrogen, and oxygen, with lesser amounts of sulfur and nitrogen. Inorganically, coal consists of a diverse range of ash-forming compounds distributed throughout the coal. The inorganic constituents can vary in concentration from several percentage points down to parts per billion of the coal. Coal is the most abundant fossil fuel in the United States, as well as the world. At the end of 2000, recoverable coal reserves in the United States, which contains the world's largest coal reserves, totaled 274 billion short tons compared to a total world reserve of 1083 billion short tons [2]. On an oil-equivalent basis, there is approximately twice as much recoverable coal in the world as oil and natural gas combined [3]; consequently, coal has been and will continue to be a major economic/energy resource, a topic that will be discussed in detail in subsequent chapters.

0 0

Post a comment