Char-coal (chär'kōl') n. A black, porous, carbonaceous material, 85 to 98 percent carbon, produced by the destructive distillation of wood and used as a fuel, filter, and absorbent.
Natural Lump Charcoal comes from partially burning wood created by heating wood without oxygen turning it into nearly 100% carbon. During the process all volatile compounds in the wood (water, hydrogen, methane and tars) pass off as vapors into the air, some of the carbon is consumed as fuel, and the rest of the carbon is converted into charcoal.
Since Charcoal is 100% pure wood carbon, it weights much less than its original state. It is also free of tars (which can contain carcinogenic compounds, like benzo-a-pyrene).
And unless it has been exposed to moisture and variable temperature, natural lump charcoal will last literally forever. The low ash production of lump charcoal is very important. Ceramic grills and Smokers have a fire bowl holding the charcoal. As the charcoal burns, the ash falls down into the bottom of the bowl. There isn't room for a whole lot of ash. Lump charcoal tends to burns hotter and faster than briquettes. Lump charcoal will also burn at whatever rate and temperature that you allow it to. Briquettes tend to burn slower as they were designed to be used in an uncontrolled environment.
There are 2 types of charcoals: the first type comes from natural wood which has been cut and made into charcoal. This is as natural as you can get. The wood comes from trees, branches and scrap pieces from saw mills. The second type comes from using processed scrap wood and tuning it into charcoal. Processed scrap wood tend to burn faster since its density is lesser than natural. This is mainly because there is less moisture into the wood at the time it is transformed into charcoals. This wood comes from wood flooring scraps, building material scrap and furniture scraps and others.
How was it made originally? Wood charcoal productions origin is very remote however the method of producing it consisted generally of piling billets of wood on their ends creating a conical shaped pile with openings at the bottom to admit air and a shaft in the middle to act as a flue. The whole pile is covered with turf or moistened clay or even additional lumber. A fire is lit at the bottom of the flue and gradually spreads outwards and upwards. The success of the operation depends upon the rate of the combustion. Under average conditions, 100 parts of wood yield about 60 parts by volume, or 25 parts by weight, of charcoal; small scale production on the spot often yields only about 50%, large scale was efficient to about 90% even by the 17th century. The operation is so delicate that it was generally left to professional charcoal burners. These often worked in solitary groups in the woods and had a rather bad social reputation, especially traveling ones who often sold a sack (priced at about a day's wage) with lots of rubbish mixed in to farmers and townsfolk.
How is it made today? In the modern method, wood is raised to a high temperature in an iron retort, and industrially important byproducts, e.g., methanol (wood alcohol or wood spirit), acetone , pyroligneous acid , and acetic acid , are saved by condensing them to their liquid form. Air is not really needed in the carbonization process, and advanced methods of charcoal production do not allow air to enter the kiln. This results in a higher yield, since no wood is burned with the air, and quality is improved. Charcoal is also obtained from substances other than wood such as nut shells and bark; that obtained from bones is called bone black, animal black, or animal charcoal.
Charcoal yields a larger amount of heat in proportion to its volume than is obtained from a corresponding quantity of wood and has the further advantage of being smokeless. The greatest amount is used as a fuel. Charcoal is often used in blacksmithing, for cooking, and for other industrial applications. One of the most important applications of wood charcoal is as a component of gunpowder . It is also used as a reducing agent in metallurgical operations, but this application was diminished by the introduction of coke . A limited quantity is made up into the form of drawing crayon. Bamboo charcoal is the principal ingredient in sumi-e, a form of Japanese ink painting that uses only black ink in various concentrations.
Because of its porous structure, finely divided charcoal is a highly efficient agent for filtering the adsorption of gases and of solids from solution. It is used in sugar refining, in water purification, in the purification of factory air, and in gas masks. Wood charcoal can remove coloring agents from solutions, but this is accomplished more efficiently by animal charcoal. By special heating or chemical processes the adsorptive property can be greatly increased; charcoal so treated is known as activated charcoal.
These charcoal kilns are located in Wildrose Canyon on the western side of Death Valley.
 “charcoal.” The American Heritage® Dictionary of the English Language, Fourth Edition, Houghton MIfflin Company, 2004, 03 Apr.2008 and taken from Dictionary.com
 Author not available, CHARCOAL., The Columbia Encyclopedia, Sixth Edition 2007
 http://pans4au.wordpress.com/ kiln pictures and article.