Charcoal is a mild carbon black and hydrocarbon ash residue produced by removing water and other volatile constituents from animals and plants. Charcoal is usually produced by slow pyrolysis - heating of wood or other substances in the absence of oxygen (see charcoal and biochar). The advantage of using charcoal rather than simply burning wood is to remove water and other components, allowing charcoal to burn to higher temperatures, and the fact that its combustion products are mainly carbon dioxide, resulting in very little smoke (ordinary wood removes large amounts of steam and carbon particles that do not burning - soot - in the smoke).
Video Charcoal
Histori
Historically, the production of wood charcoal at the site where there is a lot of wood comes from very ancient times, and generally consists of a pile of wood at the end so as to form a cone pile, the openings remaining at the bottom to Admit the air, with the central axis to serve as a funnel. The entire pile is covered with grass or moistened clay. The shooting starts at the bottom of the funnel, and gradually spreads outward and upward. The success of the operation depends on the level of combustion. Under average conditions, 100 parts of wood produce about 60 parts by volume, or 25 parts by weight, of charcoal; Small-scale production in place often yields only about 50%, while large scale becomes efficient up to about 90% even in the seventeenth century. This operation is so complicated that it is generally left to the colliers (professional charcoalers). They often live alone in small huts to take care of their wood piles. For example, in the German Harz Mountains, charcoal burners live in a cone-shaped cottage called KÃÆ'¶ten which is still widely evident today.
Large-scale production of charcoal (at its peak that uses hundreds of thousands, especially in Alpine and the surrounding forests) is a major cause of deforestation, especially in Central Europe. In the UK, many forests are managed as shrubs, which are cropped and cropped back, so that a stable supply of charcoal will be available (in principle) forever; complaints (as early as the Stuart period) about scarcity may be related to excessive exploitation of the temporary or the impossibility of increased production to adjust for increased demand. Increasing the scarcity of easily harvested timber is a major factor behind the shift to fossil fuel equivalents, especially coal and coking coal for industrial use.
The modern process of wood carbonization, whether in small pieces or like sawdust in cast iron retort, is widely practiced where rare wood, and also for the recovery of valuable byproducts (wood spirit, pyroligneous acid, tar wood), which enables the process. The question of the temperature of carbonization is important; according to J. Percy, the wood becomes brown at 220 ° C (428 ° F), dark black-brown after some time at 280 ° C (536 ° F), and an easy powder mass at 310 °. C (590 ° F). Charcoal made at 300 ° C (572 ° F) brown, soft and crumbly, and flammable at 380 ° C (716 ° F); made at a higher temperature is hard and brittle, and does not ignite until heated to about 700 ° C (1.292 ° F).
In Finland and Scandinavia, charcoal is considered a by-product of wood tar production. The best tar comes from pine, so that pine wood is cut down for tar pyrolysis. Residual charcoal is widely used as a substitute for metallurgical coke in blast furnaces for smelting. Tar production leads to rapid local deforestation. The end of tar production at the end of the nineteenth century resulted in the rapid re-greening of the affected areas.
The charcoal briquettes were first discovered and patented by Ellsworth B. A. Zwoyer from Pennsylvania in 1897 and produced by Zwoyer Fuel Company. This process was further popularized by Henry Ford, who used a byproduct of wood and sawdust from car fabrication as raw materials. Ford Charcoal later became the Kingsford Company.
Maps Charcoal
Production method
Charcoal has been made with various methods. Traditional methods in England use tongs. This is basically a pile of wooden logs (eg oaks) that lean on a chimney (logs are placed in a circle). The chimney consists of 4 wooden pillars supported by a rope. The wood is completely covered with soil and straw so no air enters. It must be switched on by loading some burning fuel into the chimney; the logs burn very slowly and turn into charcoal in a 5-day burning period. If the ground cover is torn (cracked) by fire, additional soil is placed on the crack. After the burn is complete, the chimney is installed to prevent air from entering. The true art of this production method is in managing sufficient heat (by burning part of the wood material), and transferring it to the wood parts in the carbonization process. The major disadvantage of this production method is the large number of emissions that are harmful to human health and the environment (emissions from non-burning methane). As a result of partial wood burning, the efficiency of traditional methods is low.
Modern methods use retorting technology, in which heat recovery processes are recovered from, and provided only by, combustion of gases released during carbonization. (Illustration:). Retortion results are much higher than kilns, and can reach 35% -40%.
Characteristic of the resulting charcoal depends on charred materials. The charred temperature is also important. Charcoal contains various amounts of hydrogen and oxygen and ash and other impurities which, together with their structure, determine their properties. The approximate charcoal composition for gun powders is sometimes empirically described as C 7 H 4 O. To obtain high purity coal, the source material must be free of non-volatile compounds.
Type
- Common charcoal is made from peat, coal, wood, coconut shell, or petroleum.
- Charcoal is derived from sugar carbonylation and is very pure. It is purified by boiling with acid to remove the mineral substance and then burned for a long time in the chlorine stream to remove the last traces of hydrogen. It was used by Henri Moissan in her early attempts to create synthetic diamonds.
- Activated charcoal is similar to common charcoal but is made specifically for medical use. To produce activated charcoal, the manufacturer heats the common charcoal in the presence of a gas that causes charcoal to develop a lot of internal space or "pores". These pores help the active charcoal trap chemicals.
- Clump charcoal is a traditional charcoal made directly from hardwood materials. Usually produces much less ash than briquettes.
- Japanese charcoal has removed pyroligneous acid during charcoal making; because it barely produces odor or smoke when burned. Traditional Japanese charcoal is classified into two types:
- White charcoal ( Binch? tan ) is very loud and produces a metallic sound when it is hit.
- Black charcoal
- Object is a newer type created from hardened sawdust.
- The briquette-shaped pillow is made by pressing the charcoal, usually made of sawdust and other wood byproducts, with binders and other additives. The binder is usually starch. Briquettes can also include brown coal (heat source), carbon mineral (heat source), borax, sodium nitrate (ignition aid), limestone (ash bleach agent), raw sawdust (ignition aid), and other additives.
- Charcoal sawdust briquettes are made by compressing unstained or additive wood dust. This is the preferred charcoal in Taiwan, Korea, Greece, and the Middle East. It has a round hole through the center, with a hexagonal junction. It is used mainly for barbecue because it does not produce odor, no smoking, a little ash, high heat, and long burning hours (more than 4 hours).
- Extruded charcoal is made by extruding raw wood or carbonized timber into logs without using a binder. The heat and pressure of the extrusion process hold the charcoal together. If extrusion is made of raw wood material, extruded logs are then carbonized.
Using
Charcoal has been used since ancient times for various purposes including art and medicine, but so far its most important use is as a metallurgical fuel. Charcoal is the traditional fuel of blacksmiths and other applications where strong heat is needed. Charcoal is also used historically as a source of black pigment by grinding it. In this form charcoal is important for early chemists and is a constituent of formulas for mixtures such as black powder. Because the charcoal of a high surface area can be used as a filter, and as a catalyst or as an adsorbent.
Metallurgical fuels
Charcoal burns at an intense temperature, up to 2,700 ° C (4,890 ° F). By comparison the melting point of iron is about 1,200 to 1,550 ° C (2,190-2,220 ° F). Because of its porosity, it is sensitive to air flow and the resulting heat can be moderated by controlling the flow of air to the fire. For this reason charcoal is still widely used by blacksmiths. Charcoal has been used for iron production since Roman times and steel in modern times which also provide the necessary carbon. Charcoal briquettes can burn up to approximately 2300 ° F (1,260 ° C) by forging a forced air blower.
In the 16th century, Britain had to pass legislation to prevent the country completely barren from iron production. In the charcoal of the 19th century largely replaced by coke, roasted coal, in steel production due to cost.
Industrial fuel
Historically, charcoal was used in large quantities for smelting iron in bloom and then blast furnace and iron nail. This use was replaced by coke in the 19th century as part of the Industrial Revolution.
Cooking fuel
Prior to the Industrial Revolution, charcoal was sometimes used as a cooking fuel. Modern "charcoal" charcoal, which is widely used for outdoor cooking, is made with charcoal but may also include coal as a source of energy and accelerators, binders and fillers.
Production of syngas, automotive fuel
Like many other carbon sources, charcoal can be used for the production of various syngas compositions; ie, various mixtures of CO H 2 CO 2 N 2 . Syngas is usually used as a fuel, including automotive propulsion, or as a chemical raw material.
At a time when petroleum is scarce, cars and even buses have been converted to burn wood gas (a gas mixture consisting mainly of atmospheric nitrogen depletion, but also containing flammable gases, mostly carbon monoxide) released by charcoal or burnt wood in the generator wood gas. In 1931 Tang Zhongming developed a car powered by charcoal, and these cars were popular in China until the 1950s and in occupied France during World War II (called gazogÃÆ'¨nes ).
Pyrotechnics
Charcoal is used in the production of black powder, which is widely used in fireworks production. It is usually ground into fine powder, with the airfloat level being the best commercially available particle size. When used in black powder compositions, it is often ground with other ingredients so that they are mixed together. Certain charcoal performs better when used to make black powder, these include cypress, willow, paulownia and grapevines among others.
Use of Bamboo Charcoal Cosmetics
Charcoal has become popular as a cosmetic product with many uses. This is made by getting regular bamboo, cut into smaller pieces and then boiled in distilled water to wash it. Then dried, carbonized in an oven (about 800-1200 degrees Celsius) for hours and produce raw bamboo charcoal. The use of charcoal in a beauty routine is intended to utilize highly effective absorbing properties on a microscopic scale.
carbon source
Charcoal can be used as a carbon source in chemical reactions. One example is the production of carbon disulfide through the reaction of sulfur vapor with hot charcoal. In this case the wood must be charred at high temperatures to reduce the amount of residual hydrogen and oxygen that cause side reactions.
Purification and filtering
Charcoal may be enabled to increase its effectiveness as a filter. Activated charcoal easily absorbs various organic compounds dissolved or suspended in gases and liquids. In certain industrial processes, such as purification of sucrose from sugar cane, impurities cause unwanted color, which can be removed by activated charcoal. It is also used to absorb odors and toxins in gases, such as air. Charcoal filters are also used in some types of gas masks. The active medical use of charcoal is mainly the absorption of toxins. Activated charcoal is available without a prescription, so it is used for a variety of health-related applications. For example, it is often used to reduce discomfort and embarrassment due to excessive gas (flatulence) in the digestive tract.
Animal charcoal or black bone is a carbon residue obtained from dry distillation of bone. It contains only about 10% carbon, the rest is calcium and magnesium phosphate (80%) and other inorganic materials originally present in the bone. Generally made from residues obtained in the glue and gelatin industries. The force of decolorization was applied in 1812 by Derosne for clarification of syrup obtained in sugar refining; but its use in this direction is now greatly reduced, due to the introduction of more active and manageable reagents. It is still used to some extent in laboratory practice. Decolorization forces are not permanent, lost after being used for some time; it may be revived, however, by washing and reheating. Wood charcoal also to some extent eliminates the dye from the solution, but the charcoal in animals is generally more effective.
Art
Charcoal is used in the art of drawing, making rough sketches in paintings and is one of the possible mediums to create parsemage. It should normally be preserved by the application of fixative. Artists generally use charcoal in three forms:
- Vine Charcoal is made by burning sticks or vines.
- Powdered charcoal is often used for "tones" or covering most of the image surface. Drawing over a colored area darkens it further, but the artist can also lighten (or completely remove) inside the toned area to create a brighter tone.
- Compressed charcoal charcoal powder is mixed with a rubber binder that is compressed into a round or square stick. The number of binders determines the hardness of the stick. Compressed charcoal is used in charcoal pencils.
Horticulture
One additional use of charcoal was rediscovered recently in the field of horticulture. Although American gardener has been using charcoal for a while, research on terra preta land in the Amazon has found widespread biochar use by pre-Columbian natives to convert unproductive soils into carbon-rich soil. This technique can find modern applications, both to improve soil and as a means of carbon sequestration.
Medicine
Charcoal is consumed in the past as a dietary supplement for stomach problems in the form of charcoal biscuits. It can now be consumed in the form of tablets, capsules or powders, for digestive effects. Research on its effectiveness is controversial. To measure the mucociliary transport time, use was introduced by Passali in combination with saccharin.
The red colobus monkeys in Africa have been observed eating charcoal for their own treatment purposes. Their leafy foods contain high levels of cyanide, which can cause indigestion. So they learn to consume charcoal, which absorbs cyanide and relieves indigestion. This knowledge of their dietary supplements is transmitted from mother to baby.
Charcoal has also been included in toothpaste formulas; However, there is no evidence to determine its safety and effectiveness.
Environmental implications
The use of charcoal as a smelting fuel has been revived in South America causing severe environmental, social and medical problems. Charcoal production at the sub-industry level is one of the causes of deforestation. Charcoal production is now usually illegal and almost always unregulated as in Brazil where charcoal production is a major illegal industry to make crude iron.
Massive forest destruction has been documented in areas such as Virunga National Park in the Democratic Republic of Congo, where it is considered a major threat to the survival of mountain gorillas. Similar threats are found in Zambia. In Malawi, illegal charcoal trade employs 92,800 workers and is a major source of heat and cooking fuel for 90 percent of the country's population. Some experts, such as Duncan MacQueen, Head of Researcher-Forestry Team, International Institute for Environment and Development (IIED), contend that while illegal charcoal production leads to deforestation, the regulated charcoal industry that requires sustainable reforestation and sustainable use " people clean energy efficiently - and their energy industry has a strong competitive edge. "
In popular culture
The final section of the film Le Quattro Volte (2010) provides good and long, if poetic, documentation on traditional methods of charcoal making. The Arthur Ransome Children's series of Swallows and Amazons (especially the second book, Swallowdale ) features carefully-drawn life sketches and charcoal techniques on the early 20th century, in the Lake District of UK.
See also
References
External links
- Media related to Charcoal in Wikimedia Commons
- Ã, "Charcoal". EncyclopÃÆ'Â|dia Britannica . 5 (issue 11). 1911.
- Simple technology for making charcoal
- "On Charcoal" by Peter J F Harris
- Charcoal Making at Hopewell Furnace National Historic Site in Pennsylvania - U.S. National Park Service (YouTube video)
Source of the article : Wikipedia
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