Charcoal

Charcoal is the lightweight black carbon and ash residue hydrocarbon produced by removing water and other volatile constituents from animal and vegetation substances. Charcoal is usually produced by slow pyrolysis — the heating of wood or other substances in the absence of oxygen. This process is called charcoal burning. The finished charcoal consists largely of carbon.

The advantage of using charcoal instead of just burning wood is the removal of the water and other components. This allows charcoal to burn to a higher temperature, and give off very little smoke (regular wood gives off a good amount of steam, organic volatiles, and unburnt carbon particles — soot — in its smoke).

Charcoal2
Dry charcoal
Mangrove charcoal burning video
Charcoal pile 05
Wood pile before covering it with turf or soil, and firing it (circa 1890)

History

Historically, the production of wood charcoal in locations where there is an abundance of wood dates back to a very ancient period, and generally consists of piling billets of wood on their ends so as to form a conical pile, openings being left at the bottom to admit air, with a central shaft to serve as a flue. The whole pile is covered with turf or moistened clay. The firing is begun 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%, while large-scale became efficient to about 90% even by the seventeenth century. The operation is so delicate that it was generally left to colliers (professional charcoal burners). They often lived alone in small huts in order to tend their wood piles. For example, in the Harz Mountains of Germany, charcoal burners lived in conical huts called Köten which are still much in evidence today.

Charcoal Kiln
An abandoned charcoal kiln near Walker, Arizona, USA.

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. In England, many woods were managed as coppices, which were cut and regrown cyclically, so that a steady supply of charcoal would be available (in principle) forever; 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. 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.

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 question of the temperature of the carbonization is important; according to J. Percy, wood becomes brown at 220 °C (428 °F), a deep brown-black after some time at 280 °C (536 °F), and an easily powdered mass at 310 °C (590 °F).[1] Charcoal made at 300 °C (572 °F) is brown, soft and friable, and readily inflames at 380 °C (716 °F); made at higher temperatures it is hard and brittle, and does not fire until heated to about 700 °C (1,292 °F).

In Finland and Scandinavia, the charcoal was considered the by-product of wood tar production. The best tar came from pine, thus pinewoods were cut down for tar pyrolysis. The residual charcoal was widely used as substitute for metallurgical coke in blast furnaces for smelting. Tar production led to rapid local deforestation. The end of tar production at the end of the 19th century resulted in rapid re-forestation of affected areas.

The charcoal briquette was first invented and patented by Ellsworth B. A. Zwoyer of Pennsylvania in 1897[2] and was produced by the Zwoyer Fuel Company. The process was further popularized by Henry Ford, who used wood and sawdust byproducts from automobile fabrication as a feedstock. Ford Charcoal went on to become the Kingsford Company.

Production methods

Charcoal has been made by various methods. The traditional method in Britain used a clamp. This is essentially a pile of wooden logs (e.g. seasoned oak) leaning against a chimney (logs are placed in a circle). The chimney consists of 4 wooden stakes held up by some rope. The logs are completely covered with soil and straw allowing no air to enter. It must be lit by introducing some burning fuel into the chimney; the logs burn very slowly and transform into charcoal in a period of 5 days' burning. If the soil covering gets torn (cracked) by the fire, additional soil is placed on the cracks. Once the burn is complete, the chimney is plugged to prevent air from entering.[3] The true art of this production method is in managing the sufficient generation of heat (by combusting part of the wood material), and its transfer to wood parts in the process of being carbonised. A strong disadvantage of this production method is the huge amount of emissions that are harmful to human health and the environment (emissions of unburnt methane).[4] As a result of the partial combustion of wood material, the efficiency of the traditional method is low.

Modern methods employ retorting technology, in which process heat is recovered from, and solely provided by, the combustion of gas released during carbonisation. (Illustration:[5]). Yields of retorting are considerably higher than those of kilning, and may reach 35%-40%.

The properties of the charcoal produced depend on the material charred. The charring temperature is also important. Charcoal contains varying amounts of hydrogen and oxygen as well as ash and other impurities that, together with the structure, determine the properties. The approximate composition of charcoal for gunpowders is sometimes empirically described as C7H4O. To obtain a coal with high purity, source material should be free of non-volatile compounds.

Types

Japanese Binchōtan (Japanese high-grade charcoal produced from ubame oak)
Binchōtan, Japanese high grade charcoal made from ubame oak
Ogatan(JapaneseBriquetteCharcoal)
Ogatan, charcoal briquettes made from sawdust
Burning ogatan
  • Common charcoal is made from peat, coal, wood, coconut shell, or petroleum.
  • Sugar charcoal is obtained from the carbonization of sugar and is particularly pure. It is purified by boiling with acids to remove any mineral matter and is then burned for a long time in a current of chlorine in order to remove the last traces of hydrogen.[6] It was used by Henri Moissan in his early attempt to create synthetic diamonds.
  • Activated charcoal is similar to common charcoal but is made especially for medical use. To produce activated charcoal, manufacturers heat common charcoal in the presence of a gas that causes the charcoal to develop many internal spaces or "pores". These pores help activated charcoal trap chemicals.
  • Lump charcoal is a traditional charcoal made directly from hardwood material. It usually produces far less ash than briquettes.
  • Japanese charcoal has had pyroligneous acid removed during the charcoal making; it therefore produces almost no smell or smoke when burned. The traditional charcoal of Japan is classified into two types:
    • White charcoal (Binchōtan) is very hard and produces a metallic sound when struck.
    • Black charcoal
    • Ogatan is a more recent type made from hardened sawdust.
  • Pillow shaped briquettes are made by compressing charcoal, typically made from sawdust and other wood by-products, with a binder and other additives. The binder is usually starch. Briquettes may also include brown coal (heat source), mineral carbon (heat source), borax, sodium nitrate (ignition aid), limestone (ash-whitening agent), raw sawdust (ignition aid), and other additives.
  • Sawdust briquette charcoal is made by compressing sawdust without binders or additives. It is the preferred charcoal in Taiwan, Korea, Greece, and the Middle East. It has a round hole through the center, with a hexagonal intersection. It is used primarily for barbecue as it produces no odor, no smoke, little ash, high heat, and long burning hours (exceeding 4 hours).
  • Extruded charcoal is made by extruding either raw ground wood or carbonized wood into logs without the use of a binder. The heat and pressure of the extruding process hold the charcoal together. If the extrusion is made from raw wood material, the extruded logs are subsequently carbonized.

Uses

Japanese RoundStove Charcoal
Grill charcoal made from coconut shell

Charcoal has been used since earliest times for a large range of purposes including art and medicine, but by far its most important use has been as a metallurgical fuel. Charcoal is the traditional fuel of a blacksmith's forge and other applications where an intense heat is required. Charcoal was also used historically as a source of black pigment by grinding it up. In this form charcoal was important to early chemists and was a constituent of formulas for mixtures such as black powder. Due to its high surface area charcoal can be used as a filter, and as a catalyst or as an adsorbent.

Metallurgical fuel

Charcoal burns at temperatures exceeding 1,100 degrees Celsius (2,010 degrees Fahrenheit)[7]. By comparison the melting point of iron is approximately 1,200 to 1,550 °C (2,190 to 2,820 °F). Due to its porosity, it is sensitive to the flow of air and the heat generated can be moderated by controlling the air flow to the fire. For this reason charcoal is still widely used by blacksmiths. Charcoal has been used for the production of iron since Roman times and steel in modern times where it also provided the necessary carbon. Charcoal briquettes can burn up to approximately 1,260 °C (2,300 °F) with a forced air blower forge.[8]

In the 16th century, England had to pass laws to prevent the country from becoming completely denuded of trees due to production of iron.[9] In the 19th century charcoal was largely replaced by coke, baked coal, in steel production due to cost.

Industrial fuel

Historically, charcoal was used in great quantities for smelting iron in bloomeries and later blast furnaces and finery forges. 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 occasionally used as a cooking fuel. Modern "charcoal briquettes", widely used for outdoor cooking, are made with charcoal but may also include coal as an energy source as well as accelerants, binders and filler.

Syngas production, automotive fuel

Like many other sources of carbon, charcoal can be used for the production of various syngas compositions; i.e., various CO + H2 + CO2 + N2 mixtures. The syngas is typically used as fuel, including automotive propulsion, or as a chemical feedstock.

In times of scarce petroleum, automobiles and even buses have been converted to burn wood gas (a gas mixture consisting primarily of diluting atmospheric nitrogen, but also containing combustible gasses, mostly carbon monoxide) released by burning charcoal or wood in a wood gas generator. In 1931 Tang Zhongming developed an automobile powered by charcoal, and these cars were popular in China until the 1950s and in occupied France during World War II (called gazogènes).

Pyrotechnics

Charcoal is used in the production of black powder, which is used extensively in the production of fireworks. It is usually ground into a fine powder, with airfloat grade being the finest particle size available commercially. When used in black powder compositions, it is often ball-milled with other ingredients so that they are intimately mixed together. Certain charcoals perform better when used to make black powder, these include spruce, willow, paulownia and grapevine among others.

Cosmetic Use of Bamboo Charcoal

Charcoal has started to become popular as a cosmetic product with multiple uses.[10] It is created by obtaining regular bamboo, cut down into smaller pieces and then boiled in distilled water to wash it.[10] Then it is dried out, carbonized in an oven (at roughly 800-1200 degrees Celsius) for many hours and results in raw bamboo charcoal.[10] The use of charcoal in beauty routines intends to utilize its highly effective absorbing properties at a microscopic-scale.[10]

Carbon source

Charcoal may be used as a source of carbon in chemical reactions. One example of this is the production of carbon disulphide through the reaction of sulfur vapors with hot charcoal. In that case the wood should be charred at high temperature to reduce the residual amounts of hydrogen and oxygen that lead to side reactions.

Purification and filtration

Activated Carbon
Activated carbon

Charcoal may be activated to increase its effectiveness as a filter. Activated charcoal readily adsorbs a wide range of organic compounds dissolved or suspended in gases and liquids. In certain industrial processes, such as the purification of sucrose from cane sugar, impurities cause an undesirable color, which can be removed with 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 medical use of activated charcoal is mainly the absorption of poisons.[11] 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.[12]

Animal charcoal or bone black is the carbonaceous residue obtained by the dry distillation of bones. It contains only about 10% carbon, the remainder being calcium and magnesium phosphates (80%) and other inorganic material originally present in the bones. It is generally manufactured from the residues obtained in the glue and gelatin industries. Its decolorizing power was applied in 1812 by Derosne to the clarification of the syrups obtained in sugar refining; but its use in this direction has now greatly diminished, owing to the introduction of more active and easily managed reagents. It is still used to some extent in laboratory practice. The decolorizing power is not permanent, becoming lost after using for some time; it may be revived, however, by washing and reheating. Wood charcoal also to some extent removes coloring material from solutions, but animal charcoal is generally more effective.

Art

Charcoal sticks 051907
Four sticks of vine charcoal and four sticks of compressed charcoal
Charcoal pencils 051907
Two charcoal pencils in paper sheaths that are unwrapped as the pencil is used, and two charcoal pencils in wooden sheaths

Charcoal is used in art for drawing, making rough sketches in painting and is one of the possible media for making a parsemage. It must usually be preserved by the application of a fixative. Artists generally utilize charcoal in three forms:

  • Vine charcoal is created by burning grape vines.
  • Willow charcoal is created by burning sticks.
  • Powdered charcoal is often used to "tone" or cover large sections of a drawing surface. Drawing over the toned areas darkens it further, but the artist can also lighten (or completely erase) within the toned area to create lighter tones.
  • Compressed charcoal charcoal powder mixed with gum binder compressed into round or square sticks. The amount of binder determines the hardness of the stick.[13] Compressed charcoal is used in charcoal pencils.

Horticulture

One additional use of charcoal was rediscovered recently in horticulture. Although American gardeners have been using charcoal for a short while, research on Terra preta soils in the Amazon has found the widespread use of biochar by pre-Columbian natives to turn unproductive soil into carbon rich soil. The technique may find modern application, both to improve soils and as a means of carbon sequestration.[14]

Medicine

Charcoal was consumed in the past as dietary supplement for gastric problems in the form of charcoal biscuits. Now it can be consumed in tablet, capsule or powder form, for digestive effects.[15] Research regarding its effectiveness is controversial.[16] To measure the mucociliary transport time the use was introduced by Passali in combination with saccharin.[17]

Red colobus monkeys in Africa have been observed eating charcoal for the purposes of self-medication. Their leafy diets contain high levels of cyanide, which may lead to indigestion. So they learned to consume charcoal, which absorbs the cyanide and relieves indigestion. This knowledge about supplementing their diet is transmitted from mother to infant.[18]

Charcoal has also been incorporated in toothpaste formulas; however, there is no evidence to determine its safety and effectiveness.[19]

Environmental implications

The use of charcoal as a smelting fuel has been experiencing a resurgence in South America resulting in severe environmental, social and medical problems.[20][21] Charcoal production at a sub-industrial level is one of the causes of deforestation. Charcoal production is now usually illegal and nearly always unregulated as in Brazil where charcoal production is a large illegal industry for making pig iron.[22][23][24]

Massive forest destruction has been documented in areas such as Virunga National Park in the Democratic Republic of Congo, where it is considered a primary threat to the survival of the mountain gorillas.[25] Similar threats are found in Zambia.[26] In Malawi, illegal charcoal trade employs 92,800 workers and is the main source of heat and cooking fuel for 90 percent of the nation's population.[27] Some experts, such as Duncan MacQueen, Principal Researcher–Forest Team, International Institute for Environment and Development (IIED), argue that while illegal charcoal production causes deforestation, a regulated charcoal industry that required replanting and sustainable use of the forests "would give their people clean efficient energy – and their energy industries a strong competitive advantage".[27]

In popular culture

The last section of the film Le Quattro Volte (2010) gives a good and long, if poetic, documentation of the traditional method of making charcoal.[28] The Arthur Ransome children's series Swallows and Amazons (particularly the second book, Swallowdale) features carefully drawn vignettes of the lives and the techniques of charcoal burners at the start of the 20th century, in the Lake District of the UK.

See also

References

  1. ^ Chisolm, Hugh (1910). Encyclopædia Britannica, Eleventh Edition, Volume V. New York.
  2. ^ "Barbeque – History of Barbecue". Inventors.about.com. 2010-06-15. Retrieved 2011-12-28.
  3. ^ "Geoarch". Geoarch. 1999-05-31. Archived from the original on 2004-03-15. Retrieved 2012-05-20.
  4. ^ "Roland.V. Siemons, Loek Baaijens, An Innovative Carbonisation Retort: Technology and Environmental Impact, TERMOTEHNIKA, 2012, XXXVIII, 2, 131‡138 131" (PDF).
  5. ^ "Kilning vs. Retorting: the cause of emissions of unburnt gases".
  6. ^ Wikisource Chisholm, Hugh, ed. (1911). "Carbon" . Encyclopædia Britannica. 5 (11th ed.). Cambridge University Press. pp. 305–307.
  7. ^ https://sciencing.com/hot-bonfire-8770.html
  8. ^ Cheng, Zhilong; Yang, Jian; Zhou, Lang; Liu, Yan; Wang, Qiuwang (2016-01-01). "Characteristics of charcoal combustion and its effects on iron-ore sintering performance". Applied Energy. 161: 364–374. doi:10.1016/j.apenergy.2015.09.095. ISSN 0306-2619.
  9. ^ 23 May 1615 James 1 banned use of timber for all types of furnaces
  10. ^ a b c d Ahmad, N; Isa, S.S.M.; Ramli, M.M.; Hambali, N.A.M.A.; Kasjoo, S.R.; Isa, M.M.; Nor, N.I.M.; Khalid, N. (2016). "Adsorption Properties and Potential Applications of Bamboo Charcoal: A Review" (PDF). MATEC Web of Conferences. 78: 1–7 – via edp sciences.
  11. ^ Dawson, Andrew (1997). "Activated charcoal: a spoonful of sugar". Australian Prescriber. 20: 14–16. doi:10.18773/austprescr.1997.008.
  12. ^ "Treating flatulence". NHS. NHS UK. Retrieved 27 May 2012.
  13. ^ "charcoal: powdered, compressed, willow and vine". Muse Art and Design. Muse Art and Design. 7 September 2011. Retrieved 27 May 2012.
  14. ^ Johannes Lehmann, ed. (2009). Biochar for Environmental Management: Science and Technology. Stephen Joseph. Earthscan. ISBN 978-1-84407-658-1. Retrieved 30 Dec 2013.
  15. ^ Stearn, Margaret (2007). Warts and all: straight talking advice on life's embarrassing problems. London: Murdoch Books. p. 333. ISBN 978-1-921259-84-5. Retrieved 2009-05-03.
  16. ^ Am J Gastroenterology 2005 Feb 100(2)397–400 and 1999 Jan 94(1) 208-12
  17. ^ Passali, Desiderio (1984). "Experiences in the determination of nasal mucociliary transport time". Acta Otolaryngol. 97 (3–4): 319–23. doi:10.3109/00016488409130995. PMID 6539042.
  18. ^ "Clever Monkeys: Monkeys and Medicinal Plants". PBS. 2011-09-13. Retrieved 2012-05-20.
  19. ^ Brooks, John K.; Bashirelahi, Nasir; Reynolds, Mark A. (2017-06-07). "Charcoal and charcoal-based dentifrices: A literature review". Journal of the American Dental Association. 148 (9): 661–670. doi:10.1016/j.adaj.2017.05.001. ISSN 1943-4723. PMID 28599961.
  20. ^ Michael Smith; David Voreacos (January 21, 2007). "Brazil: Enslaved workers make charcoal used to make basic steel ingredient". Seattle Times. Retrieved 16 September 2012.
  21. ^ M. Kato1, D. M. DeMarini, A. B. Carvalho, M. A. V. Rego, A. V. Andrade1, A. S. V. Bonfim and D. Loomis (2004). "World at work: Charcoal producing industries in northeastern Brazil". Occupational and Environmental Medicine. 62 (2): 128–132. doi:10.1136/oem.2004.015172. PMC 1740946. PMID 15657196. Retrieved 16 September 2012.CS1 maint: Multiple names: authors list (link)
  22. ^ "U.S. car manufacturers linked to Amazon destruction, slave labor". News.mongabay.com. 2012-05-14. Retrieved 2012-05-20.
  23. ^ Publication - May 11, 2012 (2012-05-11). "Driving Destruction in the Amazon | Greenpeace International". Greenpeace.org. Retrieved 2012-05-20.
  24. ^ The documentary film The Charcoal People (2000) [1] shows in detail the deforestation in Brazil, the poverty of the laborers and their families, and the method of constructing and using a clamp for burning the wood.
  25. ^ "Virunga National Park". Gorilla.cd. Archived from the original on 2008-10-03. Retrieved 2012-05-20.
  26. ^ "Living on Earth: Zambia's Vanishing Forests". Loe.org. 1994-03-04. Retrieved 2011-12-28.
  27. ^ a b "Is charcoal the key to sustainable energy consumption in Malawi?". UNEARTH News. July 2013. Archived from the original on 2013-08-11. Retrieved 10 August 2013.
  28. ^ "Le quattro volte (2010)". Retrieved 16 September 2012.

External links

Activated carbon

Activated carbon, also called activated charcoal, is a form of carbon processed to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions. Activated is sometimes substituted with active.

Due to its high degree of microporosity, one gram of activated carbon has a surface area in excess of 3,000 m2 (32,000 sq ft) as determined by gas adsorption. An activation level sufficient for useful application may be obtained solely from high surface area. Further chemical treatment often enhances adsorption properties.

Activated carbon is usually derived from charcoal and is sometimes used as biochar. When derived from coal or corn it is referred to as activated coal. Activated coke is derived from coke.

Barbecue grill

A barbecue grill is a device that cooks food by applying heat from below. There are several varieties of grills, with most falling into one of two categories: gas-fueled or charcoal. There is debate over which method yields superior results.

Barbiturate overdose

Barbiturate overdose is poisoning due to excessive doses of barbiturates. Symptoms typically include difficulty thinking, poor coordination, decreased level of consciousness, and a decreased effort to breathe (respiratory depression). Complications of overdose can include noncardiogenic pulmonary edema. If death occurs this is typically due to a lack of breathing.Barbiturate overdose may occur by accident or purposefully in an attempt to cause death. The toxic effects are additive to those of alcohol and benzodiazepines. The lethal dose varies with a person's tolerance and how the drug is taken. The effects of barbiturates occur via the GABA neurotransmitter. Exposure may be verified by testing the urine or blood.Treatment involves supporting a person's breathing and blood pressure. While there is no antidote, activated charcoal may be useful. Multiple doses of charcoal may be required. Hemodialysis may occasionally be considered. Urine alkalinisation has not been found to be useful. While once a common cause of overdose, barbiturates are now a rare cause.

Biochar

Biochar is charcoal used as a soil amendment. Biochar is a stable solid, rich in carbon, and can endure in soil for thousands of years. Like most charcoal, biochar is made from biomass via pyrolysis. Biochar is under investigation as an approach to carbon sequestration, as it has the potential to help mitigate climate change. It results in processes related to pyrogenic carbon capture and storage (PyCCS).

Independently, biochar can increase soil fertility of acidic soils (low pH soils), increase agricultural productivity, and provide protection against some foliar and soil-borne diseases.

Briquette

A briquette (or briquet) is a compressed block of coal dust or other combustible biomass material such as charcoal, sawdust, wood chips, peat, or paper used for fuel and kindling to start a fire. The term comes from the French language and is related to brick.

Charcoal Landing, New Jersey

Charcoal Landing was an unincorporated community located within Bass River Township in Burlington County, New Jersey, United States.

Charcoal lighter fluid

Charcoal lighter fluid is a volatile fluid used to accelerate the ignition of charcoal in a barbecue grill. It can either be petroleum based (e.g., mineral spirits) or alcohol based (usually methanol or ethanol). It can be used both with lump charcoal and briquettes. Lighter-fluid infused briquettes, that eliminate the need for separate application of lighter fluid, are available. The use of lighter fluid is somewhat controversial as the substance is combustible, harmful or fatal if swallowed, and may impart an unpleasant flavor to food cooked upon fires lit with it. A traditional alternative to using lighter fluid is a chimney starter.

The sale of petroleum-based charcoal lighter fluid is regulated in some jurisdictions due to its potential to cause photochemical smog through evaporation of its volatile organic compounds. The South Coast Air Quality Management District requires that all charcoal lighter fluids sold in its jurisdiction (essentially Southern California) meet the air quality standards set forth in District Rule 1174. Common substitutes are chimney and electric fire starters.In former Soviet countries the alcohol-based lighter fluid is sometimes consumed as a surrogate alcohol among very poor alcoholics because of its cheap price compared to vodka, just like it is with Troynoy Eau de Cologne.

Grilling

Grilling is a form of cooking that involves dry heat applied to the surface of food, commonly from above or below. Grilling usually involves a significant amount of direct, radiant heat, and tends to be used for cooking meat and vegetables quickly. Food to be grilled is cooked on a grill (an open wire grid such as a gridiron with a heat source above or below), a grill pan (similar to a frying pan, but with raised ridges to mimic the wires of an open grill), or griddle (a flat plate heated from below).Heat transfer to the food when using a grill is primarily through thermal radiation. Heat transfer when using a grill pan or griddle is by direct conduction. In the United States, when the heat source for grilling comes from above, grilling is called broiling. In this case, the pan that holds the food is called a broiler pan, and heat transfer is through thermal radiation.

Direct heat grilling can expose food to temperatures often in excess of 260 °C (500 °F). Grilled meat acquires a distinctive roast aroma and flavor from a chemical process called the Maillard reaction. The Maillard reaction only occurs when foods reach temperatures in excess of 155 °C (310 °F).Studies have shown that cooking beef, pork, poultry, and fish at high temperatures can lead to the formation of heterocyclic amines, benzopyrenes, and polycyclic aromatic hydrocarbons, which are carcinogens.Marination may reduce the formation of these compounds. Grilling is often presented as a healthy alternative to cooking with oils, although the fat and juices lost by grilling can contribute to drier food.

Gunpowder

Gunpowder, also known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur (S), charcoal (C), and potassium nitrate (saltpeter, KNO3). The sulfur and charcoal act as fuels while the saltpeter is an oxidizer. Because of its incendiary properties and the amount of heat and gas volume that it generates, gunpowder has been widely used as a propellant in firearms, artillery, rockets, and fireworks, and as a blasting powder in quarrying, mining, and road building.

Gunpowder was invented in 7th-century China and spread throughout most parts of Eurasia by the end of the 13th century. Originally developed by the Taoists for medicinal purposes, gunpowder was first used for warfare about 1000 AD.Gunpowder is classified as a low explosive because of its relatively slow decomposition rate and consequently low brisance. Low explosives deflagrate (i.e., burn) at subsonic speeds, whereas high explosives detonate, producing a supersonic wave.

Ignition of gunpowder packed behind a projectile generates enough pressure to force the shot from the muzzle at high speed, but usually not enough force to rupture the gun barrel. Gunpowder thus makes a good propellant, but is less suitable for shattering rock or fortifications with its low-yield explosive power. However, by transferring enough energy (from the burning gunpowder to the mass of the cannonball, and then from the cannonball to the opposing fortifications by way of the impacting ammunition) eventually a bombardier may wear down an opponent's fortified defenses.

Gunpowder was widely used to fill fused artillery shells (and used in mining and civil engineering projects) until the second half of the 19th century, when the first high explosives were put into use. Gunpowder is no longer used in modern weapons, nor is it used for industrial purposes, due to its relatively inefficient cost compared to newer alternatives such as dynamite and ammonium nitrate/fuel oil. Today gunpowder firearms are limited primarily to hunting, target shooting, and bulletless historical reenactments.

Hibachi

The hibachi (Japanese: 火鉢, "fire bowl") is a traditional Japanese heating device. It consists of a round, cylindrical, or a box-shaped, open-topped container, made from or lined with a heatproof material and designed to hold burning charcoal.

In North America, the term "hibachi" refers to a small cooking stove heated by charcoal (called shichirin in Japanese) or to an iron hot plate (called teppan in Japanese) used in teppanyaki restaurants.

Pencil

A pencil is an implement for writing or drawing, constructed of a narrow, solid pigment core in a protective casing that prevents the core from being broken and/or marking the user’s hand.

Pencils create marks by physical abrasion, leaving a trail of solid core material that adheres to a sheet of paper or other surface. They are distinct from pens, which dispense liquid or gel ink onto the marked surface.

Most pencil cores are made of graphite powder mixed with a clay binder. Graphite pencils (traditionally known as 'lead pencils') produce grey or black marks that are easily erased, but otherwise resistant to moisture, most chemicals, ultraviolet radiation and natural aging. Other types of pencil cores, such as those of charcoal, are mainly used for drawing and sketching. Coloured pencils are sometimes used by teachers or editors to correct submitted texts, but are typically regarded as art supplies—especially those with waxy core binders that tend to smear when erasers are applied to them. Grease pencils have a softer, crayon-like waxy core that can leave marks on smooth surfaces such as glass or porcelain.

The most common pencil casing is thin wood, usually hexagonal in section but sometimes cylindrical or triangular, permanently bonded to the core. Casings may be of other materials, such as plastic or paper. To use the pencil, the casing must be carved or peeled off to expose the working end of the core as a sharp point. Mechanical pencils have more elaborate casings which are not bonded to the core; instead, they support separate, mobile pigment cores that can be extended or retracted through the casing's tip as needed. These casings can be reloaded with new cores (usually graphite) as the previous ones are exhausted.

Shades of black

Shades of black are colors that differ only slightly from pure black. These colors have a low lightness. From photometric point of view, a color which differs slightly from black always has low relative luminance. Variations of black include what are commonly termed off-black colors, which may be considered part of a neutral color scheme, usually in interior design as a part of a background for brighter colors. Black and dark gray colors are powerful accent colors that suggest weight, dignity, formality, and solemnity.In color theory, a shade is a pure color mixed with black. It decreases its lightness while nearly conserving its chromaticity. Strictly speaking, a "shade of black" is always a pure black itself and a "tint of black" would be a neutral gray. Unlike these, many off-black colors possess a hue and a colorfulness (also called saturation).

Colors often considered "shades of black" include onyx, black olive, charcoal, and jet; these colors and other variations of black are shown below.

Shades of gray

Variations of gray or grey include achromatic grayscale shades, which lie exactly between white and black, and nearby colors with low colorfulness. A selection of a number of these various colors is shown below.

Terra preta

Terra preta (Portuguese pronunciation: [ˈtɛʁɐ ˈpɾetɐ], locally [ˈtɛha ˈpɾeta], literally "black soil" in Portuguese) is a type of very dark, fertile artificial (anthropogenic) soil found in the Amazon Basin. It is also known as "Amazonian dark earth" or "Indian black earth". In Portuguese its full name is terra preta do índio or terra preta de índio ("black soil of the Indian", "Indians' black earth"). Terra mulata ("mulatto earth") is lighter or brownish in color.

Terra preta owes its characteristic black color to its weathered charcoal content, and was made by adding a mixture of charcoal, bone, broken pottery, compost and manure to the otherwise relatively infertile Amazonian soil. A product of indigenous soil management and slash-and-char agriculture, the charcoal is stable and remains in the soil for thousands of years, binding and retaining minerals and nutrients.Terra preta is characterized by the presence of low-temperature charcoal residues in high concentrations; of high quantities of tiny pottery shards; of organic matter such as plant residues, animal feces, fish and animal bones, and other material; and of nutrients such as nitrogen, phosphorus, calcium, zinc and manganese. Fertile soils such as terra preta show high levels of microorganic activities and other specific characteristics within particular ecosystems.

Terra preta zones are generally surrounded by terra comum ([ˈtɛhɐ koˈmũ] or [ˈtɛhɐ kuˈmũ]), or "common soil"; these are infertile soils, mainly acrisols, but also ferralsols and arenosols. Deforested arable soils in the Amazon are productive for a short period of time before their nutrients are consumed or leached away by rain or flooding. This forces farmers to migrate to an unburned area and clear it (by fire). Terra preta is less prone to nutrient leaching because of its high concentration of charcoal, microbial life and organic matter. The combination accumulates nutrients, minerals and microorganisms and withstands leaching.

Terra preta soils were created by farming communities between 450 BCE and 950 CE. Soil depths can reach 2 meters (6.6 ft). It is reported to regenerate itself at the rate of 1 centimeter (0.4 in) per year in Brazil's Amazonian basin.

Than Quang Ninh FC

Than Quang Ninh Football Club (Vietnamese: Câu lạc bộ Bóng đá Than Quảng Ninh) is a professional football club, based in Quảng Ninh Province, Vietnam. They are now playing in V.League 1.

The team is currently playing at Cẩm Phả Stadium

Ward Charcoal Ovens State Historic Park

Ward Charcoal Ovens State Historic Park is an area designated for historic preservation and public recreation located 20 miles (32 km) south of the town of Ely in White Pine County, Nevada. The 700-acre (280 ha) state park protects beehive-shaped charcoal ovens constructed in the latter half of the 19th century.

Wood gas

Wood gas is a syngas fuel which can be used as a fuel for furnaces, stoves and vehicles in place of gasoline, diesel or other fuels. During the production process biomass or other carbon-containing materials are gasified within the oxygen-limited environment of a wood gas generator to produce hydrogen and carbon monoxide. These gases can then be burnt as a fuel within an oxygen rich environment to produce carbon dioxide, water and heat. In some gasifiers this process is preceded by pyrolysis, where the biomass or coal is first converted to char, releasing methane and tar rich in polycyclic aromatic hydrocarbons.

Yakitori

Yakitori (Japanese: 焼き鳥) is a Japanese type of skewered chicken. Its preparation involves skewering the meat with kushi (串), a type of skewer typically made of steel, bamboo, or similar materials. Afterwards, they are grilled over a charcoal fire. During or after cooking, the meat is typically seasoned with tare sauce or salt.

Yuchanyan

Yuchanyan is an early Neolithic cave site in Dao County (Daoxian), Hunan, China. The site yielded sherds of ceramic vessels and other artifacts which were dated by analysis of charcoal and bone collagen, giving a date range of 17,500 to 18,300 years old for the pottery. The pottery specimens may be the oldest known examples of pottery.The cave yielded fragmentary remains of 2 or more ceramic vessels, in addition to large amounts of ash, a rich animal bone assemblage, cobble and flake artifacts, bone tools, and shell tools. The artifacts indicate that the cave was a Late Paleolithic foragers' camp. Here we report on the radiocarbon ages of the sediments based on analyses of charcoal and bone collagen. The best-preserved charcoal and bone samples were identified by prescreening in the field and laboratory. The dates range from around 21,000 to 13,800 cal BP. The age of the ancient pottery ranges between 18,300 and 15,430 cal BP. Charcoal and bone collagen samples located above and below one of the fragments produced dates of around 18,000. These ceramic potsherds therefore provide some of the earliest evidence for pottery making in China.

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