Ash

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This article is about the residue of burning a material. Not to be confused with Volcanic ash or Ash (plant).For other uses, see Ash (disambiguation).
Wood ash Wood ash.jpg
Wood ash

Ash is the solid remnants of fires. [1] Specifically, ash refers to all non-aqueous, non-gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash is the non-gaseous, non-liquid residue after complete combustion.

Contents

Ashes as the end product of incomplete combustion are mostly mineral, but usually still contain an amount of combustible organic or other oxidizable residues. The best-known type of ash is wood ash, as a product of wood combustion in campfires, fireplaces, etc. The darker the wood ashes, the higher the content of remaining charcoal from incomplete combustion. The ashes are of different types. Some ashes contain natural compounds that make soil fertile. Others have chemical compounds that can be toxic but may break up in soil from chemical changes and microorganism activity.

Like soap, ash is also a disinfecting agent (alkaline). [2] The World Health Organization recommends ash or sand as alternative for handwashing when soap is not available. [3] Before industrialization, ash soaked in water was the primary means of obtaining potash.

Natural occurrence

Ash occurs naturally from any fire that burns vegetation, and may disperse in the soil to fertilise it, or clump under it for long enough to carbonise into coal.

Composition

The composition of the ash varies depending on the product burned and its origin. The "ash content" or "mineral content" of a product is derived its incineration under temperatures ranging from 150 °C (302 °F) to 900 °C (1,650 °F). [4]

Wood and plant matter

The composition of ash derived from wood and other plant matter varies based on plant species, parts of the plants (such as bark, trunk, or young branches with foliage), type of soil, and time of year. The composition of these ashes also differ greatly depending on mode of combustion.

Wood ashes, in addition to residual carbonaceous materials (unconsumed embers, activated carbons impregnated with carbonaceous particles, tars, various gases, etc.), contain a between 20% and 50% calcium in the form of calcium oxide and are generally rich in potassium carbonate. Ashes derived from grasses, and the Gramineae family in particular, are rich in silica. [5] The color of the ash comes from small proportions of inorganic minerals such as iron oxides and manganese. The oxidized metal elements that constitute wood ash are mostly considered alkaline.

For example, ash collected from wood boilers is composed of [6]

The pH of the ash is between 10 and 13, mostly due to the fact that the oxides of calcium, potassium, and sodium are strong bases. Acidic components such as carbon dioxide, phosphoric acid, silicic acid, and sulfuric acid are rarely present and, in the presence of the previously mentioned bases, are generally found in the form of salts, respectively carbonates, phosphates, silicates and sulphates.

Strictly speaking, calcium and potassium salts produce the aforementioned calcium oxide (also known as quicklime) and potassium during the combustion of organic matter. But, in practice, quicklime is only obtained via lime-kiln, and potash (from potassium carbonate) or baking soda (from sodium carbonate) is extracted from the ashes.

Other substances such as sulfur, chlorine, iron or sodium only appear in small quantities. Still others are rarely found in wood, such as aluminum, zinc, and boron. (depending on the trace elements drawn from the soil by the incinerated plants).

Mineral content in ash depends on the species of tree burned, even in the same soil conditions. More chloride is found in conifer trees than broadleaf trees, with seven times as much found in spruces than in oak trees. There is twice as much phosphoric acid in the European aspen than in oaks and twice as much magnesium in elm trees than in the Scotch pine.

Ash composition also varies by which part of the tree was burnt. Silicon and calcium salts are more abundant in bark than in wood, while potassium salts are primarily found in wood. Compositional variation also occurred based on the season in which the tree died.

Specific types

Joss paper ash. With wind and dispersion, the size of particulates decreases, while the number of particles increases. HK Sheung Wan Wing Lok Street fire burning offering papers Chinese style December 2018 IX2 02.jpg
Joss paper ash. With wind and dispersion, the size of particulates decreases, while the number of particles increases.

Cremation ashes

Cremation ashes, also called cremated remains or "cremains," are the bodily remains left from cremation. [7] They often take the form of a grey powder resembling coarse sand. While often referred to as ashes, the remains primarily consist of powdered bone fragments due to the cremation process, which eliminates the body's organic materials. [8] People often store these ashes in containers like urns, although they are also sometimes buried or scattered in specific locations. [9]

Food ashes

In food processing, mineral and ash content is used to characterize the presence of organic and inorganic components in food for monitoring quality, nutritional quantification and labeling, analyzing microbiological stability, and more. [4] This process can be used to measure minerals like calcium, sodium, potassium, and phosphorus as well as metal content such as lead, mercury, cadmium, and aluminum.

Joss paper ash

Analysis of the contents of ash samples shows that joss paper burning can emit many pollutants detrimental to air quality. There is a significant amount of heavy metals in the dust fume and bottom ash, e.g., aluminium, iron, manganese, copper, lead, zinc and cadmium. [10] [11]

"Burning of joss paper accounted for up to 42% of the atmospheric rBC [refractory black carbon] mass, higher than traffic (14-17%), crop residue (10-17%), coal (18-20%) during the Hanyi festival in northwest China", according to a 2022 study, "the overall air quality can be worsened due to the practice of uncontrolled burning of joss paper during the festival, which is not just confined to the people who do the burning," and "burning joss paper during worship activities is common in China and most Asian countries with similar traditions." [12]

Slash-and-burn ash

Wildfire ash

High levels of heavy metals, including lead, arsenic, cadmium, and copper were found in the ash debris following the 2007 Californian wildfires. A national clean-up campaign was organised ... [13] In the devastating California Camp Fire (2018) that killed 85 people, lead levels increased by around 50 times in the hours following the fire at a site nearby (Chico). Zinc concentration also increased significantly in Modesto, 150 miles away. Heavy metals such as manganese and calcium were found in numerous California fires as well. [14]

Others

Other Properties

Aging process

Global distillation

Uses

Fertilizer

Ashes have been used since the Neolithic period as fertilizer because they are rich in minerals, especially potash and essential nutrients. They are the main fertilizer in slash-and-burn agriculture, which eventually evolved into controlled burn and forest clearing practices. People in ancient history already possessed extensive knowledge of the nutrients produced by (from social 10th textbook)(manufacturing industries )different ashes. [15] For clay soil in particular, using ash without modification or using charrée, ash whose minerals have been washed with water, was necessary.

Laundry

Because ashes contain potash, they can be used to make biodegradable laundry detergent. The demand for organic products has led to renewed interest for laundry using ash derived from wood. [16] The French word for laundry lessive is from the Latin word lixivia, which means a substance made from ash and used to wash laundry. This usage also developed into a small, traditional architectural structure to the west of Rhône mainstem: the bugadière, a masonry structure built with stone or cob, that looks like a cabinet and that carries dirty laundry and fireplace ash; when the bugadière is full, the laundry and ash are moved to a laundry container and boiled in water.

Laundry using ash derived from wood has the benefit of being free, easy to produce, sustainable, and as efficient as standard laundry washing methods.

Health effects

Effect on precipitation

"Particles of dust or smoke in the atmosphere are essential for precipitation. These particles, called 'condensation nuclei,' provide a surface for water vapor to condense upon. This helps water droplets gather together and become large enough to fall to the earth" [17]

Effect on climate change

See also

Related Research Articles

In chemistry, an alkali is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the Arrhenius definition of a base, and they are still among the most common bases.

<span class="mw-page-title-main">Carbonate</span> Salt or ester of carbonic acid

A carbonate is a salt of carbonic acid,, characterized by the presence of the carbonate ion, a polyatomic ion with the formula CO2−3. The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate groupO=C(−O−)2.

<span class="mw-page-title-main">Potassium</span> Chemical element with atomic number 19 (K)

Potassium is a chemical element; it has symbol K and atomic number 19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals, all of which have a single valence electron in the outer electron shell, which is easily removed to create an ion with a positive charge. In nature, potassium occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac-colored flame. It is found dissolved in seawater, and occurs in many minerals such as orthoclase, a common constituent of granites and other igneous rocks.

<span class="mw-page-title-main">Potash</span> Salt mixture

Potash includes various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, plant ashes or wood ash soaked in water in a pot, the primary means of manufacturing potash before the Industrial Era. The word potassium is derived from potash.

<span class="mw-page-title-main">Potassium nitrate</span> Chemical compound

Potassium nitrate is a chemical compound with a sharp, salty, bitter taste and the chemical formula KNO3. It is a potassium salt of nitric acid. This salt consists of potassium cations K+ and nitrate anions NO−3, and is therefore an alkali metal nitrate. It occurs in nature as a mineral, niter. It is a source of nitrogen, and nitrogen was named after niter. Potassium nitrate is one of several nitrogen-containing compounds collectively referred to as saltpetre.

<span class="mw-page-title-main">Sodium carbonate</span> Chemical compound

Sodium carbonate is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood, sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the chloralkali process.

<span class="mw-page-title-main">Potassium hydroxide</span> Inorganic compound (KOH)

Potassium hydroxide is an inorganic compound with the formula KOH, and is commonly called caustic potash.

The Leblanc process was an early industrial process for making soda ash used throughout the 19th century, named after its inventor, Nicolas Leblanc. It involved two stages: making sodium sulfate from sodium chloride, followed by reacting the sodium sulfate with coal and calcium carbonate to make sodium carbonate. The process gradually became obsolete after the development of the Solvay process.

The Solvay process or ammonia–soda process is the major industrial process for the production of sodium carbonate (soda ash, Na2CO3). The ammonia–soda process was developed into its modern form by the Belgian chemist Ernest Solvay during the 1860s. The ingredients for this are readily available and inexpensive: salt brine (from inland sources or from the sea) and limestone (from quarries). The worldwide production of soda ash in 2005 was estimated at 42 million tonnes, which is more than six kilograms (13 lb) per year for each person on Earth. Solvay-based chemical plants now produce roughly three-quarters of this supply, with the remaining being mined from natural deposits. This method superseded the Leblanc process.

<span class="mw-page-title-main">Water softening</span> Removing positive ions from hard water

Water softening is the removal of calcium, magnesium, and certain other metal cations in hard water. The resulting soft water requires less soap for the same cleaning effort, as soap is not wasted bonding with calcium ions. Soft water also extends the lifetime of plumbing by reducing or eliminating scale build-up in pipes and fittings. Water softening is usually achieved using lime softening or ion-exchange resins, but is increasingly being accomplished using nanofiltration or reverse osmosis membranes.

An ashery is a factory that converts hardwood ashes into lye, potash, or pearlash. Asheries were common in newly settled areas of North America during the late 18th century and much of the 19th century, when excess wood was available as settlers cleared their land for farming. Hardwood ashes contain abundant levels of potassium carbonate and potassium hydroxide, the principal components of the products being produced.

In analytical chemistry, ashing or ash content determination is the process of mineralization by complete combustion for preconcentration of trace substances prior to a chemical analysis, such as chromatography, or optical analysis, such as spectroscopy.

<span class="mw-page-title-main">Hexafluorosilicic acid</span> Octahedric silicon compound

Hexafluorosilicic acid is an inorganic compound with the chemical formula H
2SiF
6. Aqueous solutions of hexafluorosilicic acid consist of salts of the cation and hexafluorosilicate anion. These salts and their aqueous solutions are colorless.

<i>Soda inermis</i> Species of plant

Soda inermis, the opposite-leaved saltwort, oppositeleaf Russian thistle, or barilla plant, is a small, annual, succulent shrub that is native to the Mediterranean Basin. It is a halophyte that typically grows in coastal regions and can be irrigated with salt water. The plant was previously classified as Salsola soda, now regarded as a synonym.

A pyrotechnic composition is a substance or mixture of substances designed to produce an effect by heat, light, sound, gas/smoke or a combination of these, as a result of non-detonative self-sustaining exothermic chemical reactions. Pyrotechnic substances do not rely on oxygen from external sources to sustain the reaction.

<span class="mw-page-title-main">Manganese(II) sulfate</span> Chemical compound

Manganese(II) sulfate usually refers to the inorganic compound with the formula MnSO4·H2O. This pale pink deliquescent solid is a commercially significant manganese(II) salt. Approximately 260,000 tonnes of manganese(II) sulfate were produced worldwide in 2005. It is the precursor to manganese metal and many other chemical compounds. Manganese-deficient soil is remediated with this salt.

<span class="mw-page-title-main">Alkali soil</span> Soil type with pH > 8.5

Alkali, or alkaline, soils are clay soils with high pH, a poor soil structure and a low infiltration capacity. Often they have a hard calcareous layer at 0.5 to 1 metre depth. Alkali soils owe their unfavorable physico-chemical properties mainly to the dominating presence of sodium carbonate, which causes the soil to swell and difficult to clarify/settle. They derive their name from the alkali metal group of elements, to which sodium belongs, and which can induce basicity. Sometimes these soils are also referred to as alkaline sodic soils. Alkaline soils are basic, but not all basic soils are alkaline.

<span class="mw-page-title-main">Forest glass</span> Type of glass produced in medieval Europe

Forest glass is a type of medieval glass produced in northwestern and central Europe from approximately 1000–1700 AD using wood ash and sand as the main raw materials and made in factories known as glasshouses in forest areas. It is characterized by a variety of greenish-yellow colors, the earlier products often being of crude design and poor quality, and was used mainly for everyday vessels and increasingly for ecclesiastical stained glass windows. Its composition and manufacture contrast sharply with Roman and pre-Roman glassmaking, centered on Mediterranean and contemporaneous Byzantine and Islamic glassmaking to the east. This article is mainly interested in the production of forest glass in Great Britain, though it was also made in other parts of Europe.

<span class="mw-page-title-main">Wood ash</span> Residue powder left after the combustion of wood

Wood ash is the powdery residue remaining after the combustion of wood, such as burning wood in a fireplace, bonfire, or an industrial power plant. It is largely composed of calcium compounds, along with other non-combustible trace elements present in the wood, and has been used for many purposes throughout history.

References

  1. ↑ "the definition of ash". www.dictionary.com. Retrieved 2018-06-18.
  2. ↑ Howard et al. 2002: Healthy Villages A guide for communities and community health workers. CHAPTER 8 Personal, domestic and community hygiene. WHO. Accessed Oct. 2014. http://www.who.int/water_sanitation_health/hygiene/settings/hvchap8.pdf
  3. ↑ WHO 2014: Water Sanitation Health. How can personal hygiene be maintained in difficult circumstances? Accessed Oct. 2014
  4. 1 2 McClements, D. Julian. "Analysis of Ash and Minerals". Analysis of Food Products Lectures. Retrieved 2024-06-15.
  5. ↑ Pépin, Denis (2013). Composts et paillis: pour un jardin sain, facile et productif. Terre vivante. p. 54. ISBN   978-2360980918.
  6. ↑ Couturier, Christian; Brasset, Thierry. "Gestion et valorisation de cendres de chaufferies bois" [Management and recovery of wood boiler ashes](PDF) (in French). Agence de l'Environnement et de la Maîtrse de l'Energie. Archived from the original (PDF) on 2015-01-15. Retrieved 2024-06-24.
  7. ↑ "What Are Cremains? (& What to Do with Them)". usurnsonline.com. 31 May 2022.
  8. ↑ "Education | Cremation ashes". www.lonite.ca.
  9. ↑ "What To Do With Cremated Remains". cremation.com. Retrieved 25 June 2023.
  10. ↑ Giang, Lam Van; Thanh, Tran; Hien, Truong Thanh; Tan, Lam Van; Thi Bich Phuong, Tran; Huu Loc, Ho (2021). "Heavy metals emissions from joss paper burning rituals and the air quality around a specific incinerator". Materials Today: Proceedings. 38: 2751–2757. doi: 10.1016/j.matpr.2020.08.686 . S2CID   226353498.
  11. ↑ Khezri, B.; Chan, Y. Y.; Tiong, L. Y. D.; Webster, R. D. (2015). "Annual air pollution caused by the Hungry Ghost Festival". Environmental Science: Processes & Impacts. 17 (9): 1578–1586. doi:10.1039/C5EM00312A. hdl: 10356/82684 . PMID   26220212.
  12. ↑ Lin C, Huang RJ, Duan J, Zhong H, Xu W, Wu Y, Zhang R (April 2022). "Large contribution from worship activities to the atmospheric soot particles in northwest China". Environ Pollut. 299: 118907. Bibcode:2022EPoll.29918907L. doi:10.1016/j.envpol.2022.118907. PMID   35091017.
  13. ↑ Finlay SE, Moffat A, Gazzard R, Baker D, Murray V (November 2012). "Health impacts of wildfires". PLOS Currents. 4: e4f959951cce2c. doi: 10.1371/4f959951cce2c (inactive 1 November 2024). PMC   3492003 . PMID   23145351.{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)
  14. ↑ "Wildfire smoke can increase hazardous toxic metals in air, study finds | Climate crisis | The Guardian". 21 July 2021.
  15. ↑ Sobrado Correa, H. (2004). La fertilisation des terres dans la Galice de l'Ancien Régime (xviie-xixe siècle). Histoire & Sociétés Rurales, 21, 39-72. https://doi.org/10.3917/hsr.021.0039
  16. ↑ La lessive à la cendre, faite maison
  17. ↑ "Precipitation". National Geographic. 19 Oct 2023. Retrieved 19 Aug 2024.
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