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63-458: 4 H -Pyran was first isolated and characterized in 1962 via pyrolysis of 2-acetoxy-3,4-dihydro-2 H -pyran. It was found to be unstable, particularly in the presence of air. 4 H -pyran easily disproportionates to the corresponding dihydropyran and the pyrylium ion, which is easily hydrolyzed in aqueous medium. Although the pyrans themselves have little significance in chemistry, many of their derivatives are important biological molecules, such as

126-454: A charcoal kiln , the heat is supplied by burning part of the starting material itself, with a limited supply of oxygen . The material can also be heated in a closed retort . Modern charcoal briquettes used for outdoor cooking may contain many other additives, e.g. coal . The history of wood charcoal production spans ancient times, rooted in the abundance of wood in various regions. The process typically involves stacking wood billets to form

189-413: A charcoal pile or clamp . This was essentially a pile of wooden logs (e.g. seasoned oak) leaning in a circle against a chimney. The chimney consisted of 4 wooden stakes held up by some rope. In the clamp too the logs were 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 burned slowly and transformed into charcoal over

252-468: 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 , where they were called gazogènes . 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 air float grade being

315-471: A conical pile, allowing air to enter through openings at the bottom, and igniting the pile gradually. Charcoal burners, skilled professionals tasked with managing the delicate operation, often lived in isolation to tend their wood piles. Throughout history, the extensive production of charcoal has been a significant contributor to deforestation, particularly in regions like Central Europe. However, various management practices, such as coppicing , aimed to maintain

378-435: A deep brown-black after some time at 280 °C (540 °F), and an easily powdered mass at 310 °C (590 °F). Charcoal made at 300 °C (570 °F) is brown, soft and friable, and readily inflames at 380 °C (720 °F); made at higher temperatures it is hard and brittle, and does not fire until heated to about 700 °C (1,300 °F). Modern methods employ retorting technology, in which process heat

441-919: A different classification that focuses on the pyrolysis operating conditions and heating system used, which have an impact on the yield of the pyrolysis products. Vapor residence time: 10-100 min Heating rate: 0.1-1 °C/s Feedstock size: 5-50 mm Biochar~35 Gases~35 Vapor residence time: 0.5-20 s Heating rate: 1.0-10 °C/s Feedstock size: 1-5 mm Biochar~25 Gases~35 Vapor residence time: 0.5-5 s Heating rate: 10-200 °C/s Feedstock size: <3 mm Biochar~20 Gases~30 Vapor residence time: <5 s Heating rate: >1000 °C/s Feedstock size: <0.2 mm Biochar~12 Gases~13 Vapor residence time: >15 s Heating rate: 10-300 °C/s Vapor residence time: 10-100 min Heating rate: 0.1-1 °C/s Biochar~22 Gases~45 Pyrolysis has been used for turning wood into charcoal since ancient times. The ancient Egyptians used

504-400: A filter, catalyst , or adsorbent. Charcoal burns at temperatures exceeding 1,100 degrees Celsius (2,010 degrees Fahrenheit). 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

567-456: 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 gaseous solutions, as in home air purifiers and some types of gas mask . The medical use of activated charcoal

630-407: A high percentage of heavy tar fractions, which condense at relatively high temperatures, preventing its direct use in gas burners and internal combustion engines, unlike syngas. The process is used heavily in the chemical industry , for example, to produce ethylene , many forms of carbon , and other chemicals from petroleum, coal, and even wood, or to produce coke from coal . It is used also in

693-503: 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

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756-414: A microscopic scale. 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. Charcoal may be activated to increase its effectiveness as

819-425: A period of 5 days. If the soil covering became torn or cracked by the fire, additional soil was placed on the cracks. Once the burn was complete, the chimney was plugged to prevent air from entering. The true art of this production method was in managing the sufficient generation of heat, by combusting part of the wood material, and the transfer of the heat to the wood in the process of being carbonized. The operation

882-539: A raw material in pyrotechnics. It is also utilized in cosmetics, horticulture, animal husbandry, medicine, and environmental sustainability efforts, such as carbon sequestration. However, the production and utilization of charcoal can have adverse environmental impacts, including deforestation and emissions. Illegal and unregulated charcoal production, particularly in regions like South America and Africa, poses significant challenges to environmental conservation efforts. The production of wood charcoal in locations where there

945-465: 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". Recent assessments of charcoal imported to Europe have shown that many charcoal products are produced from tropical wood, often of undeclared origin. In an analysis of barbecue charcoal marketed in Germany,

1008-660: A short time, research on Terra preta soils in Amazonia has discovered the widespread use of biochar by pre-Columbian natives to ameliorate unproductive soil into soil rich in carbon . The technique may find modern application, both to improve soils and as a means of carbon sequestration . Charcoal is mixed with feed, added to litter , or used in the treatment of manure . Poultry benefits from using charcoal in this manner. A concern that activated charcoal might be used unscrupulously to allow livestock to tolerate low quality feed contaminated with aflatoxins resulted in

1071-597: A smelting fuel has been experiencing a resurgence in South America resulting in severe environmental, social and medical problems. 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 . Massive forest destruction has been documented in areas such as Virunga National Park in

1134-613: A steady supply of wood for charcoal production. The scarcity of easily accessible wood resources eventually led to the transition to fossil fuel equivalents like coal. Modern methods of charcoal production involve carbonizing wood in retorts, yielding higher efficiencies compared to traditional kilning methods. The properties of charcoal depend on factors such as the material charred and the temperature of carbonization. Charcoal finds diverse applications, including metallurgical fuel in iron and steel production, industrial fuel, cooking and heating fuel, reducing agent in chemical processes, and as

1197-426: A way to improve the health of people burning raw biomass for cooking and/or heating. 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. To contain the charcoal and use it for cooking purposes, a barbecue grill may be used. A small Japanese charcoal grill is known as a shichirin . A brazier

1260-591: Is a container used to burn charcoal or other solid fuel. To start the charcoal burning is harder than starting a wood fire and charcoal lighter fluid may be employed. A chimney starter or electric charcoal starter are tools to help with starting to light charcoal. Approximately 75% of fuel burned in Haiti is charcoal. Certain types of charcoal, such as wood charcoal, are used for reducing heated metallic oxides to their respective metals: Charcoal can also be used to reduce super heated steam to hydrogen (along with

1323-479: Is an abundance of wood dates back to ancient times. It generally began with piling billets of wood on their ends to form a conical pile. Openings were left at the bottom to admit air , with a central shaft serving as a flue . The whole pile was covered with turf or moistened clay . The firing began at the bottom of the flue, and the fire gradually spread outward and upward. The traditional method in Britain used

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1386-485: Is generally more effective as an adsorption filter due to its increased porosity and surface area. Charcoal is used for drawing , making rough sketches in painting , and is one of the possible media used for making a parsemage . It usually must be preserved by the application of a fixative . Artists generally utilize charcoal in four forms: One additional use of charcoal was rediscovered recently for horticulture . Although American gardeners have used charcoal for

1449-427: Is mainly the absorption of poisons . 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 bone black is the carbonaceous residue obtained by the dry distillation of bones. It contains only about 10% carbon,

1512-605: Is no evidence to determine its safety and effectiveness. Red colobus monkeys in Africa have been observed eating charcoal for self-medication. Because their leafy diets contain high levels of cyanide , which may lead to indigestion, they learned to consume charcoal, which absorbs the cyanide and relieves discomfort. This knowledge is transmitted from mother to infant. Production and utilization of charcoal, like any use of woody biomass as fuel, typically results in emissions and can contribute to deforestation. The use of charcoal as

1575-501: Is not needed. In the mid-20th century, "smokeless" legislation in Europe required cleaner-burning techniques, such as coke fuel and smoke-burning incinerators as an effective measure to reduce air pollution The coke-making or "coking" process consists of heating the material in "coking ovens" to very high temperatures (up to 900 °C or 1,700 °F) so that the molecules are broken down into lighter volatile substances, which leave

1638-454: Is one of the processes involved in charring of the wood or pyrolysis of biomass. In general, pyrolysis of organic substances produces volatile products and leaves char , a carbon-rich solid residue. Extreme pyrolysis, which leaves mostly carbon as the residue, is called carbonization . Pyrolysis is considered one of the steps in the processes of gasification or combustion. Laypeople often confuse pyrolysis gas with syngas. Pyrolysis gas has

1701-421: Is recovered from, and solely provided by, the combustion of gas released during carbonization. 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

1764-485: Is still widely used by blacksmiths. Charcoal has been used for the production of iron and steel (where it also provided the necessary carbon) since at least 2000 BCE , with artifacts having been found in Proto-Hittite layers at Kaman-Kalehöyük . Charcoal briquettes can burn up to approximately 1,260 °C (2,300 °F) with a forced air blower forge. In the 16th century, England had to pass laws to prevent

1827-489: Is used as an adsorbent for a wide range of chemical substances. Biochar is the residue of incomplete organic pyrolysis, e.g., from cooking fires. It is a key component of the terra preta soils associated with ancient indigenous communities of the Amazon basin . Terra preta is much sought by local farmers for its superior fertility and capacity to promote and retain an enhanced suite of beneficial microbiota, compared to

1890-440: Is used to obtain showers of golden sparks in pyrotechnic compositions. Charcoal is also incorporated in multiple cosmetic products. It can be produced from regular bamboo cut into small pieces and boiled in water to remove soluble compounds. Raw bamboo charcoal is obtained after drying and carbonization in an oven at elevated temperature. The role of charcoal in cosmetics is based on its highly effective absorbing properties at

1953-425: Is used to produce many kinds of carbon; these can be used for fuel, as reagents in steelmaking (coke), and as structural materials. Charcoal is a less smoky fuel than pyrolyzed wood. Some cities ban, or used to ban, wood fires; when residents only use charcoal (and similarly treated rock coal, called coke ) air pollution is significantly reduced. In cities where people do not generally cook or heat with fires, this

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2016-637: The Democratic Republic of Congo , where it is considered a primary threat to the survival of the mountain gorillas. Similar threats are found in Zambia . 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. 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,

2079-514: The Kingsford Company . 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 (430 °F),

2142-534: The World Wildlife Fund found that most products contain tropical wood. As a notable exception, reference is made to barbecue charcoal imports from Namibia , where charcoal is typically produced from surplus biomass resulting from woody plant encroachment . Charcoal trafficking in Somalia is an economic and environmental issue with significant regional-security implications. The last section of

2205-401: The pyranoflavonoids . The term pyran is also often applied to the saturated ring analog, which is more properly referred to as tetrahydropyran (oxane). In this context, the monosaccharides containing a six-membered ring system are known as pyranoses . This article about chemical compounds is a stub . You can help Misplaced Pages by expanding it . Pyrolysis Pyrolysis is

2268-469: The 17th century. 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). As a result of the partial combustion of wood material, the efficiency of the traditional method is low. The massive production of charcoal (at its height employing hundreds of thousands, mainly in Alpine and neighbouring forests)

2331-593: The Association of American Feed Control Officials banning it in 2012 from use in commercial livestock feeds. Charcoal in the form of charcoal biscuits was consumed in the past for gastric problems. Now it can be consumed in tablet, capsule, or powder form for digestive effects. Research regarding its effectiveness is controversial. Charcoal has been used in combination with saccharin in research to measure mucociliary transport time. Charcoal has also been incorporated into toothpaste formulas; however, there

2394-519: The Industrial Revolution, charcoal was occasionally used as a cooking fuel . It is counted as a smokeless fuel ; that is, the carbon is sufficiently pure that burning it causes substantially less air pollution than burning the original uncarbonized organic material would. In the 20th century, clean-air legislation mandated smokeless fuels (mostly coke or charcoal) in many areas of Europe. In the 21st century, charcoal has been advocated as

2457-422: The boiling point of water or other solvents). It differs from other processes like combustion and hydrolysis in that it usually does not involve the addition of other reagents such as oxygen (O 2 , in combustion) or water (in hydrolysis). Pyrolysis produces solids ( char ), condensable liquids, (light and heavy oils and tar ), and non-condensable gasses. Pyrolysis is different from gasification . In

2520-455: The burning of firewood , in the traditional manufacture of charcoal , and in the steam cracking of crude oil. Conversely, the starting material may be heated in a vacuum or in an inert atmosphere to avoid chemical side reactions (such as combustion or hydrolysis). Pyrolysis in a vacuum also lowers the boiling point of the byproducts, improving their recovery. When organic matter is heated at increasing temperatures in open containers,

2583-476: The chemical process industry, pyrolysis refers to a partial thermal degradation of carbonaceous materials that takes place in an inert (oxygen free) atmosphere and produces both gases, liquids and solids. The pyrolysis can be extended to full gasification that produces mainly gaseous output, often with the addition of e.g. water steam to gasify residual carbonic solids, see Steam reforming . Specific types of pyrolysis include: Other pyrolysis types come from

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2646-432: The conversion of natural gas (primarily methane ) into hydrogen gas and solid carbon char, recently introduced on an industrial scale. Aspirational applications of pyrolysis would convert biomass into syngas and biochar , waste plastics back into usable oil, or waste into safely disposable substances. Pyrolysis is one of the various types of chemical degradation processes that occur at higher temperatures (above

2709-468: The country from becoming completely denuded of trees due to production of iron. In the 19th century charcoal was largely replaced by coke in steel production due to cost, even though coke usually adds sulphur and sometimes other deleterious contaminants to the pig iron. Wooded metallurgical regions devoid of coal like Sweden, the Urals, or Siberia transitioned from charcoal in the early 20th century. Prior to

2772-497: The end of the 19th century resulted in rapid re-forestation of affected areas. The American form of the charcoal briquette was first invented and patented by Ellsworth B. A. Zwoyer of Pennsylvania in 1897 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

2835-561: The film Le Quattro Volte (2010) gives a good and long, if poetic, documentation of the traditional method of making charcoal. 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. Antonín Dvořák's opera King and Charcoal Burner

2898-413: 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. Charcoal produces fine dark orange/golden sparks . Usually, powder with a mesh size from 10 to 325

2961-546: The following processes generally occur, in successive or overlapping stages: Because pyrolysis takes place at high temperatures which exceed the autoignition temperature of the produced gases, an explosion risk exists if oxygen is present. To control the temperature of pyrolysis systems careful temperature control is needed and can be accomplished with an open source pyrolysis controller. Pyrolysis also produces various toxic gases, mainly carbon monoxide . The greatest risk of fire, explosion and release of toxic gases comes when

3024-576: The formation of carbon monoxide): Like many other sources of carbon, charcoal can be used for the production of various syngas compositions; i.e., various CO + H 2 + CO 2 + N 2 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

3087-399: The introduction of more active and easily managed reagents, but it is still employed to some extent in laboratory practice. The bleaching action of the charcoal in solution diminishes as it adsorbs colored contaminants, and it must be reactivated periodically by separate washing and reheating. While wood charcoal effectively removes some pigments and contaminants from solutions, bone charcoal

3150-475: The liquid fraction obtained from the pyrolysis of cedar wood, in their embalming process. The dry distillation of wood remained the major source of methanol into the early 20th century. Pyrolysis was instrumental in the discovery of many chemical substances, such as phosphorus from ammonium sodium hydrogen phosphate NH 4 NaHPO 4 in concentrated urine , oxygen from mercuric oxide , and various nitrates . Pyrolysis generally consists in heating

3213-482: The material above its decomposition temperature , breaking chemical bonds in its molecules. The fragments usually become smaller molecules, but may combine to produce residues with larger molecular mass, even amorphous covalent solids . In many settings, some amounts of oxygen, water, or other substances may be present, so that combustion, hydrolysis, or other chemical processes may occur besides pyrolysis proper. Sometimes those chemicals are added intentionally, as in

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3276-460: The process of thermal decomposition of materials at elevated temperatures, often in an inert atmosphere without access to oxygen. The word pyrolysis is coined from the Greek -derived elements pyro- (from Ancient Greek πῦρ : pûr - "fire, heat, fever") and lysis (λύσις : lúsis - "separation, loosening"). Pyrolysis is most commonly used in the treatment of organic materials. It

3339-407: The remaining 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 bleaching power was applied in 1812 by Derosne for clarifying sugar syrup , but its use in this direction has now greatly diminished. Today it is seldom used for this purpose due to

3402-407: The solid residue left from petroleum refining. The original vascular structure of the wood and the pores created by escaping gases combine to produce a light and porous material. By starting with a dense wood-like material, such as nutshells or peach stones , one obtains a form of charcoal with particularly fine pores (and hence a much larger pore surface area), called activated carbon , which

3465-403: The structure, determine the properties. The approximate composition of charcoal for gunpowders is sometimes empirically described as C 7 H 4 O. To obtain a coal with high purity, source material should be free of non-volatile compounds. Wood charcoal is obtained as the residue by destructive distillation of wood such that the products are: Charcoal has been used since earliest times for

3528-452: The sugars have been produced by the breakdown of polysaccharides ). The food goes brown and changes flavor. The distinctive flavors are used in many dishes; for instance, caramelized onion is used in French onion soup . The temperatures needed for caramelization lie above the boiling point of water. Frying oil can easily rise above the boiling point. Putting a lid on the frying pan keeps

3591-442: The system is starting up and shutting down, operating intermittently, or during operational upsets. Inert gas purging is essential to manage inherent explosion risks. The procedure is not trivial and failure to keep oxygen out has led to accidents. Conversion of CBD to THC can be brought about by pyrolysis. Pyrolysis has many applications in food preparation. Caramelization is the pyrolysis of sugars in food (often after

3654-489: The typical red soil of the region. Efforts are underway to recreate these soils through biochar , the solid residue of pyrolysis of various materials, mostly organic waste. Charcoal Charcoal 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. In the traditional version of this pyrolysis process, called charcoal burning, often by forming

3717-517: The vessel, and a porous but hard residue that is mostly carbon and inorganic ash. The amount of volatiles varies with the source material, but is typically 25–30% of it by weight. High temperature pyrolysis is used on an industrial scale to convert coal into coke . This is useful in metallurgy , where the higher temperatures are necessary for many processes, such as steelmaking . Volatile by-products of this process are also often useful, including benzene and pyridine . Coke can also be produced from

3780-427: The water in, and some of it re-condenses, keeping the temperature too cool to brown for longer time. Pyrolysis of food can also be undesirable, as in the charring of burnt food (at temperatures too low for the oxidative combustion of carbon to produce flames and burn the food to ash ). Carbon and carbon-rich materials have desirable properties but are nonvolatile, even at high temperatures. Consequently, pyrolysis

3843-548: Was a major cause of deforestation , especially in Central Europe . Complaints (as early as the Stuart period ) about shortages may stem from 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. But the increasing scarcity of easily harvested wood

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3906-492: Was a major factor behind the switch to fossil fuel equivalents, mainly coal and brown coal for industrial use. 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

3969-648: Was so delicate that it was generally left to colliers (professional charcoal burners). They often lived alone in small huts to tend their wood piles. For example, in the Harz Mountains of Germany, charcoal burners lived in conical huts called Köten which still exist today. The success of the operation depends upon the rate of the combustion . 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

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