Zwoyer of Pennsylvania in 1897 and was produced by the Zwoyer Fuel Company. The American form of the charcoal briquette was first invented and patented by Ellsworth B. The end of tar production at the end of the 19th century resulted in rapid re-forestation of affected areas. Tar production led to rapid local deforestation. The residual charcoal was widely used as substitute for metallurgical coke in blast furnaces for smelting. The best tar came from pine, thus pinewoods were cut down for tar pyrolysis. In Finland and Scandinavia, the charcoal was considered the by-product of wood tar production. Charcoal made at 300В вЊ (570В вЏ) is brown, soft and friable, and readily inflames at 380В вЊ (720В вЏ) made at higher temperatures it is hard and brittle, and does not fire until heated to about 700В вЊ (1,300В вЏ). Percy, wood becomes brown at 220В вЊ (430В вЏ), a deep brown-black after some time at 280В вЊ (540В вЏ), and an easily powdered mass at 310В вЊ (590В вЏ). The question of the temperature of the carbonization is important according to J. The modern process of carbonizing wood, either in small pieces or as sawdust in cast iron retorts, is extensively practiced where wood is scarce, and also for the recovery of valuable byproducts ( wood spirit, pyroligneous acid, wood tar), which the process permits. The increasing scarcity of easily harvested wood was a major factor behind the switch to fossil fuel equivalents, mainly coal and brown coal for industrial use. Complaints (as early as the Stuart period) about shortages may relate to the results of temporary over-exploitation or the impossibility of increasing production to match growing demand. In England, many woods were managed as coppices, which were cut and regrown cyclically, so that a steady supply of charcoal was available. The massive production of charcoal (at its height employing hundreds of thousands, mainly in Alpine and neighbouring forests) was a major cause of deforestation, especially in Central Europe. ДЄn abandoned charcoal kiln near Walker, Arizona, USA. For example, in the Harz Mountains of Germany, charcoal burners lived in conical huts called KГ¶ten which are extant today. They often lived alone in small huts to tend their wood piles.

The operation is so delicate that it was generally left to colliers (professional charcoal burners). Under average conditions wood yields about 60% charcoal by volume, or 25% by weight small-scale production methods often yield only about 50% by volume, while large-scale methods enabled higher yields of about 90% by the 17th century. The success of the operation depends upon the rate of the combustion. The firing is begun at the bottom of the flue, and gradually spreads outward and upward. The whole pile is covered with turf or moistened clay. Openings are left at the bottom to admit air, with a central shaft serving as a flue. It generally begins with piling billets of wood on their ends to form a conical pile. The production of wood charcoal in locations where there is an abundance of wood dates back to ancient times. ( November 2010) ( Learn how and when to remove this template message)

Unsourced material may be challenged and removed. Please help improve this article by adding citations to reliable sources. This section needs additional citations for verification. Charcoal burns at a higher temperature than wood, with hardly a visible flame, and releases almost nothing except heat and carbon dioxide (One kilogram of charcoal contains 680 to 820 grams of carbon, which when combined with oxygen from the atmosphere form 2.5 to 3В kg of carbon dioxide). The soot and smoke commonly given off by wood fires result from incomplete combustion of those volatiles. The visible flame in these is due to combustion of the volatile gases exuded as the wood turns into charcoal. It also happens inadvertently while burning wood, as in a fireplace or wood stove. This process happens naturally when combustion is incomplete, and is sometimes used in radiocarbon dating. Modern 'charcoal' briquettes used for outdoor cooking may contain many other additives, e.g. The material can also be heated in a closed retort. In the traditional version of this pyrolysis process, called charcoal burning, often by forming a charcoal kiln, the heat is supplied by burning part of the starting material itself, with a limited supply of oxygen.

Wood pile before covering it with turf or soil, and firing it (circa 1890)Д¬harcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents.

The long dark charcoal