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-- Alex 08:31, 17 July 2006 (UTC)
I still think that there should be a section on bio-oil: 1) There are 4 sections on solid products of pyrolysis: charcoal, biochar, coke and carbon fiber. There is only 1 section on biofule that looks at liquid products. This is unbalanced. 2) The current section on biofuel ignores the real difficulties encountered when using bio-oil as a fuel. 3) Although some companies, recently, have used bio-oil as a biofuel, the companies that have been in business for more than 10 years produce bio-oil for non-fuel applications (Ensyn and RTI, for example). It would better to replace the "bio-fuel" title by "bio-oil" and, then, talk about fuel and other applications. Cbriens ( talk) 05:55, 12 January 2009 (UTC)
I slightly modified the first sentence of the Anhydrous Pyrolysis section to make it compatible with the rest of the article, i.e. the presence of a section on Hydrous Pyrolysis.-- Cbriens 17:06, 27 October 2007 (UTC)
This page needs a subsection on Waste pyrolysis plants which are being globally proposed as alternative waste treatment solutions.-- Alex 11:48, 25 July 2006 (UTC)
It says: "Pyrolysis typically occurs under pressure and at operating temperatures above 430°C (800°F)." This phrase applies only to *some* process of *industrial* pyrolysis, which should be specified (perhaps pyrolysis of wood scraps and sawdust to generate charcoal+?). Pyrolysis is a general term and it can occur anywhere (nature, kitchen, lab, etc.), to any (organic?) substance, at temperatures as low as 100°C. Jorge Stolfi 01:43, 11 Mar 2004 (UTC)
Why is this article in the firefighting category? -- Andrew 20:04, Feb 7, 2005 (UTC)
some discussion recently in New Scientist about unburnt pyrolysis products: http://environment.newscientist.com/channel/earth/mg19526151.900-ignition-impossible-when-wildfires-set-the-air-alight.html http://www.newscientist.com/article/mg19526200.600-burning-bush.html David Woodward 08:08, 28 October 2007 (UTC)
I believe this term is sometimes used more loosely to mean "heating to decompose organic materials" (absense of O2 not specified). I know that this is not really correct, but I have see this in, for example, analytic glassware cleaning protocols. Can anyone confirm this looser definition? ike9898 22:27, 6 December 2005 (UTC)
There's three closely related articles on this general topic: This one, Destructive distillation and Cracking (chemistry). The cracking article is mostly concerned with petroleum, but the Pyrolysis and Destructive distillation have large overlaps. I think at least those two should be merged. Toiyabe 22:30, 22 February 2006 (UTC)
I have suggested that the stub "Dry distillation" be merged into this article because:
I have tagged both this article and the stub with merge tags. - mbeychok 21:34, 7 May 2006 (UTC)
These should not be merged. According to the "dry distillation" entry, there is an intent to collect the byproducts from a reaction, so it is a process. Pyrolysis refers to general chemical thermal decomposition, with or without oxygen present, and the compound doesn't even have to be organic. Sometimes industrial or lab terminology hijacks a strict definition to make it into more of a process definition. If this is the case for a specific use of the term "pyrolysis", a link should be added to point to "dry distillation". 208.223.129.170 14:38, 1 June 2006 (UTC)
I am not especially happy that the two industrial examples above are listed as examples of pyrolysis. Strictly speaking, they are not. Both involve partial combustion using air in order to generate the heat required for the pyrolysis. In both examples about 10% of the material is combusted, to pyrolyse the other 90%. I am not arguing that these processes don't contain pyrolysis, they do. But they are not examples of pyrolysis in its true sense, which must, by necessity involve indirect heating (to avoid contact with oxygen or toher reagents). What do you think?
I added other processes that do not use partial combustion-- Cbriens 18:37, 2 January 2007 (UTC)
Presently ( http://en.wikipedia.org/?title=Pyrolysis&oldid=105365069) there are multiple links in the article to companies working with pyrolysis technology. They are incorporated into the text. However, to me, it makes the article seem a little more like a buyers guide than an encyclopædic article. Any thoughts? Are there any Wikipedia policies, discussions or guidelines on this? Also, unless I receive any good reasons to keep these links, I'll probably remove them. -- Tunheim 09:59, 6 February 2007 (UTC)
I agree. Remove them. No disrespect to the companies concerned, but they do not deserve special status amongst hundreds of others. The examples of particular company processes give detail but not depth or understanding to the article. Indeed, they tend to give a bias and a suggestion that this is something new. Chemical Engineer 21:49, 1 September 2007 (UTC)
i'm wikied out at the moment, having left some jobs undone, i will probably be back, but here are some to-do's for anybody
This page should include a link to "Wood Gas" and to "Charcoal". The pyrolysis of wood produces a solid; the charcoal, and also gasses; the "wood gasses". These are all related concepts. I haven't figured out how to add links or I would do it myself. Alexander Selkirk Alexselkirk1704 ( talk) 17:37, 12 April 2008 (UTC)
Microwaves should be mentioned as they are used for this. 80.186.110.204 ( talk) 08:44, 3 July 2009 (UTC)
I think this should be changed because of the product called Bio-Oil (TM) http://www.bio-oil-direct.co.uk/ Eugene-elgato ( talk) 18:35, 8 February 2009 (UTC)
Some mention of the carcinogens produced by the pyrolysis of food would be appropriate. 78.144.248.102 ( talk) 10:42, 30 October 2009 (UTC)
This site mentions that heterocyclic amines and polycyclic aromatic hydrocarbons are known carcinogens produced when muscle meat is cooked at high temperatures. The site does not specify whether this is due to pyrolysis or some other process. http://www.cancer.gov/cancertopics/factsheet/Risk/cooked-meats The12thMan ( talk) 21:41, 8 July 2011 (UTC)
The article has been modified so as to imply that pyrolysis applies only to organic substances. However the term seems to be used also for inorganic substances, e.g. "Yakubovich and coworkers obtained insoluble polymers [...] by the pyrolysis of phosphazene phosphoxides at 220°C." [1]. So I will restore the original wording "mainly used for organics" (but not exclusively). All the best, -- Jorge Stolfi ( talk) 22:55, 4 January 2010 (UTC)
The article states that pyrolysis is a special case of thermolysis. However, reading both articles, I could not find or imagine an example of thermolysis that is not a pyrolyis. In fact, the IUPAC Gold Book defines them as synonyms. http://goldbook.iupac.org/P04961.html and http://goldbook.iupac.org/T06326.html. Do you agree with that? 200.164.157.164 ( talk) 19:21, 14 April 2010 (UTC)
Pyrolysis is usually reported as a special case of thermolysis in review papers examining biomass as pyrolysis feedstock. I agree that coal for instance can be described as operated on by pyrolysis and thermolysis (with no difference at all?). If it is just a semantics issue, it'd be worth a note in the article about which scientific "cliques" use what term. I know torrefaction is usually considered a low temperature (200 celsius or less?) form of pyrolysis.
Hero of Ludi (
talk)
03:36, 17 August 2012 (UTC)
I expanded (actually rewrote) the Chemistry section to add more detail and improve the sense. I agreed with the original author, but just tried to add a little more detail from a personal survey of recent research. I neglected to add additional citations (I just left the original citation in place). I will add citations.
I also added a little more detail to the Biofuel section and linked out to biomass sources by name. I didn't add citations, but they could be added. Hero of Ludi ( talk) 03:40, 17 August 2012 (UTC)
I believe (but don't have refs) that laser-cutting of wood produces it's effect by pyrolysis. If that's correct, it would be a useful addition to the Examples section. SteveBaker ( talk) 20:10, 16 April 2013 (UTC)
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Cheers.— cyberbot II Talk to my owner:Online 21:48, 1 June 2016 (UTC)
"Using tires as fuel produce equal energy as burning oil and 25% more energy than burning coal.[23]"
This statement is meaningless. Tabby ( talk) 10:39, 1 August 2016 (UTC)
Today I removed this content. Unless one cooks like my grandmother, pyrolysis and the kitchen are not connected concepts. "Pyrolysis also plays an important role in several cooking procedures, such as baking, frying, grilling, and caramelizing.
Pyrolysis occurs whenever food is exposed to high enough temperatures in a dry environment, such as roasting, baking, toasting, or grilling. It is the chemical process responsible for the formation of the golden-brown crust in foods prepared by those methods.
In normal cooking, the main food components that undergo pyrolysis are carbohydrates (including sugars, starch, and fibre) and proteins. (See: Maillard reaction.) Pyrolysis of fats requires a much higher temperature, and, since it produces toxic and flammable products (such as acrolein), it is, in general, avoided in normal cooking. However, it may occur when one is grilling fatty meats over hot coals.
Even though cooking is normally carried out in air, the temperatures and environmental conditions are such that there is little or no combustion of the original substances or their decomposition products. In particular, the pyrolysis of proteins and carbohydrates begins at temperatures much lower than the ignition temperature of the solid residue, and the volatile subproducts are too diluted in air to ignite. (In flambé dishes, the flame is due mostly to combustion of the alcohol, while the crust is formed by pyrolysis as in baking.)
Pyrolysis of carbohydrates and proteins requires temperatures substantially higher than 100 °C (212 °F), so pyrolysis does not occur as long as free water is present, e.g., in boiling food — not even in a pressure cooker. When heated in the presence of water, carbohydrates and proteins suffer gradual hydrolysis rather than pyrolysis. For most foods, pyrolysis is usually confined to the outer layers of food, and begins only after those layers have dried out.
Food pyrolysis temperatures are, however, lower than the boiling point of lipids, so pyrolysis occurs when frying in vegetable oil or suet, or basting meat in its own fat.
Pyrolysis also plays an essential role in the production of barley tea, coffee, and roasted nuts such as peanuts and almonds. As these consist mostly of dry materials, the process of pyrolysis is not limited to the outermost layers but extends throughout the materials. In all these cases, pyrolysis creates or releases many of the substances that contribute to the flavor, color, and biological properties of the final product. It may also destroy some substances that are toxic, unpleasant in taste, or those that may contribute to spoilage.
Controlled pyrolysis of sugars starting at 170 °C (338 °F) produces caramel, a beige to brown water-soluble product widely used in confectionery and (in the form of caramel coloring) as a coloring agent for soft drinks and other industrialized food products.
Solid residue from the pyrolysis of spilled and splattered food creates the brown-black encrustation often seen on cooking vessels, stove tops, and the interior surfaces of ovens."-- Smokefoot ( talk) 01:29, 10 January 2018 (UTC)
This WP:UNDUE ("hippie science") was also removed. The article is about pyrolysis, not someone's dream for how if might make the world wonderful..."[Pyrolysis of plastics produces fuels] with a higher cetane value and lower sulphur content than conventional diesel.<ref>[http://www.zerowaste.sa.gov.au/upload/resource-centre/publications/waste-to-energy/Case%20Study%203%20Cynar%20Plastics%20to%20Fuel%20FINAL.pdf Cynar Plastics to Diesel]. Ricardo – AEA Ltd (2013)</ref> Using pyrolysis to extract fuel from end-of-life plastic is a second-best option after recycling, is environmentally preferable to landfill, and can help reduce dependency on fossil fuels and geo-extraction."
Long essay on biochar, which is tangential to this topic. Reads like a rant. "Biochar improves the [[soil structure|soil texture]] and [[ecology]], increasing its ability to retain fertilizers and release them slowly. It naturally contains many of the [[micronutrient]]s needed by plants, such as [[selenium]]. Biochar is also safer than other "natural" fertilizers such as animal [[manure]], since it has been [[disinfect]]ed at high temperature. And, since it releases nutrients at a slow rate, it greatly reduces the risk of [[water table]] contamination.<ref name='gardaus1'> {{cite news | first = Peter | last = Cundall | title = Fact Sheet: Pete's Patch | date = 2007-10-27 | publisher = Australian Broadcasting Corporation | url = http://www.abc.net.au/gardening/stories/s2071694.htm | work = Gardening Australia | accessdate = 2008-07-10}}</ref> Biochar is also being considered for [[carbon dioxide sink|carbon sequestration]], with the aim of [[mitigation of global warming]].<ref name='horstman1'> {{cite news | first=Mark | last=Horstman | title=Agrichar – A solution to global warming? | date=2007-09-23 | publisher=Australian Broadcasting Corporation | url =http://www.abc.net.au/catalyst/stories/s2012892.htm | work =ABC TV Science: Catalyst | accessdate = 2008-07-10 }} </ref><ref> {{cite news |url=http://news.bbc.co.uk/1/hi/england/7993034.stm |title=Trial to reverse global warming |publisher=BBC News |accessdate=2009-04-21 | date=2009-04-09}} </ref><ref> {{cite news |url=http://www.economist.com/sciencetechnology/displaystory.cfm?story_id=14302001 |title=The virtues of biochar: A new growth industry? |date=2009-08-27 |publisher=The Economist |accessdate=2009-08-30 }} </ref> The solid, carbon-containing char produced can be sequestered in the ground, where it could remain for several hundred to a few thousand years.<ref>[http://www.biochar-international.org/biochar/faqs#q9 Frequently Asked Questions about Biochar | International Biochar Initiative]. Biochar-international.org (2013-04-19). Retrieved on 2013-06-01.</ref> Research continues about the processes responsible for long-term sequestration of carbon in soils.<ref>{{Cite journal|last=Schmidt|first=Michael W. I.|last2=Torn|first2=Margaret S.|last3=Abiven|first3=Samuel|last4=Dittmar|first4=Thorsten|last5=Guggenberger|first5=Georg|last6=Janssens|first6=Ivan A.|last7=Kleber|first7=Markus|last8=Kögel-Knabner|first8=Ingrid|last9=Lehmann|first9=Johannes|date=2011-10-06|title=Persistence of soil organic matter as an ecosystem property|url=http://www.nature.com/nature/journal/v478/n7367/abs/nature10386.html|journal=Nature|language=en|volume=478|issue=7367|pages=49–56|doi=10.1038/nature10386|issn=0028-0836|bibcode=2011Natur.478...49S}}</ref>"
-- Smokefoot ( talk) 14:38, 10 January 2018 (UTC)
"Neanderthals used pyrolysis of birch bark to produce a pitch with which they secured flaked stones to spear shafts.<ref>[https://www.pbs.org/wgbh/nova/evolution/defy-stereotypes.html NOVA – Official Website | Neanderthals Defy Stereotypes]. Pbs.org. Retrieved on 2016-12-16.</ref> Recently, researchers have developed a process to pyrolyze birch bark to produce an oil that can replace [[phenol]] in [[phenol formaldehyde resin]] (these resins are mostly used to manufacture [[plywood]]).<ref>Dongbing Li, Franco Berruti, Cedric Briens, "Autothermal fast pyrolysis of birch bark with partial oxidation in a fluidized bed reactor", Fuel, Volume 121, 1 April 2014, Pages 27–38</ref>" removed as tangential.-- Smokefoot ( talk) 14:48, 10 January 2018 (UTC)
I'm reasonably smart and sciencey and stuff but I have no idea what is going on in the graphic that is labeled "Simplified depiction of pyrolysis chemistry". I respectfully suggest it needs a really good descriptive caption or it should be eliminated. Kirkpete ( talk) 23:32, 28 February 2019 (UTC)
The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for deletion:
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This article was the subject of a Wiki Education Foundation-supported course assignment, between 24 August 2022 and 9 December 2022. Further details are available on the course page. Student editor(s): 07JOS ( article contribs).
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This is the
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Pyrolysis article. This is not a forum for general discussion of the article's subject. |
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-- Alex 08:31, 17 July 2006 (UTC)
I still think that there should be a section on bio-oil: 1) There are 4 sections on solid products of pyrolysis: charcoal, biochar, coke and carbon fiber. There is only 1 section on biofule that looks at liquid products. This is unbalanced. 2) The current section on biofuel ignores the real difficulties encountered when using bio-oil as a fuel. 3) Although some companies, recently, have used bio-oil as a biofuel, the companies that have been in business for more than 10 years produce bio-oil for non-fuel applications (Ensyn and RTI, for example). It would better to replace the "bio-fuel" title by "bio-oil" and, then, talk about fuel and other applications. Cbriens ( talk) 05:55, 12 January 2009 (UTC)
I slightly modified the first sentence of the Anhydrous Pyrolysis section to make it compatible with the rest of the article, i.e. the presence of a section on Hydrous Pyrolysis.-- Cbriens 17:06, 27 October 2007 (UTC)
This page needs a subsection on Waste pyrolysis plants which are being globally proposed as alternative waste treatment solutions.-- Alex 11:48, 25 July 2006 (UTC)
It says: "Pyrolysis typically occurs under pressure and at operating temperatures above 430°C (800°F)." This phrase applies only to *some* process of *industrial* pyrolysis, which should be specified (perhaps pyrolysis of wood scraps and sawdust to generate charcoal+?). Pyrolysis is a general term and it can occur anywhere (nature, kitchen, lab, etc.), to any (organic?) substance, at temperatures as low as 100°C. Jorge Stolfi 01:43, 11 Mar 2004 (UTC)
Why is this article in the firefighting category? -- Andrew 20:04, Feb 7, 2005 (UTC)
some discussion recently in New Scientist about unburnt pyrolysis products: http://environment.newscientist.com/channel/earth/mg19526151.900-ignition-impossible-when-wildfires-set-the-air-alight.html http://www.newscientist.com/article/mg19526200.600-burning-bush.html David Woodward 08:08, 28 October 2007 (UTC)
I believe this term is sometimes used more loosely to mean "heating to decompose organic materials" (absense of O2 not specified). I know that this is not really correct, but I have see this in, for example, analytic glassware cleaning protocols. Can anyone confirm this looser definition? ike9898 22:27, 6 December 2005 (UTC)
There's three closely related articles on this general topic: This one, Destructive distillation and Cracking (chemistry). The cracking article is mostly concerned with petroleum, but the Pyrolysis and Destructive distillation have large overlaps. I think at least those two should be merged. Toiyabe 22:30, 22 February 2006 (UTC)
I have suggested that the stub "Dry distillation" be merged into this article because:
I have tagged both this article and the stub with merge tags. - mbeychok 21:34, 7 May 2006 (UTC)
These should not be merged. According to the "dry distillation" entry, there is an intent to collect the byproducts from a reaction, so it is a process. Pyrolysis refers to general chemical thermal decomposition, with or without oxygen present, and the compound doesn't even have to be organic. Sometimes industrial or lab terminology hijacks a strict definition to make it into more of a process definition. If this is the case for a specific use of the term "pyrolysis", a link should be added to point to "dry distillation". 208.223.129.170 14:38, 1 June 2006 (UTC)
I am not especially happy that the two industrial examples above are listed as examples of pyrolysis. Strictly speaking, they are not. Both involve partial combustion using air in order to generate the heat required for the pyrolysis. In both examples about 10% of the material is combusted, to pyrolyse the other 90%. I am not arguing that these processes don't contain pyrolysis, they do. But they are not examples of pyrolysis in its true sense, which must, by necessity involve indirect heating (to avoid contact with oxygen or toher reagents). What do you think?
I added other processes that do not use partial combustion-- Cbriens 18:37, 2 January 2007 (UTC)
Presently ( http://en.wikipedia.org/?title=Pyrolysis&oldid=105365069) there are multiple links in the article to companies working with pyrolysis technology. They are incorporated into the text. However, to me, it makes the article seem a little more like a buyers guide than an encyclopædic article. Any thoughts? Are there any Wikipedia policies, discussions or guidelines on this? Also, unless I receive any good reasons to keep these links, I'll probably remove them. -- Tunheim 09:59, 6 February 2007 (UTC)
I agree. Remove them. No disrespect to the companies concerned, but they do not deserve special status amongst hundreds of others. The examples of particular company processes give detail but not depth or understanding to the article. Indeed, they tend to give a bias and a suggestion that this is something new. Chemical Engineer 21:49, 1 September 2007 (UTC)
i'm wikied out at the moment, having left some jobs undone, i will probably be back, but here are some to-do's for anybody
This page should include a link to "Wood Gas" and to "Charcoal". The pyrolysis of wood produces a solid; the charcoal, and also gasses; the "wood gasses". These are all related concepts. I haven't figured out how to add links or I would do it myself. Alexander Selkirk Alexselkirk1704 ( talk) 17:37, 12 April 2008 (UTC)
Microwaves should be mentioned as they are used for this. 80.186.110.204 ( talk) 08:44, 3 July 2009 (UTC)
I think this should be changed because of the product called Bio-Oil (TM) http://www.bio-oil-direct.co.uk/ Eugene-elgato ( talk) 18:35, 8 February 2009 (UTC)
Some mention of the carcinogens produced by the pyrolysis of food would be appropriate. 78.144.248.102 ( talk) 10:42, 30 October 2009 (UTC)
This site mentions that heterocyclic amines and polycyclic aromatic hydrocarbons are known carcinogens produced when muscle meat is cooked at high temperatures. The site does not specify whether this is due to pyrolysis or some other process. http://www.cancer.gov/cancertopics/factsheet/Risk/cooked-meats The12thMan ( talk) 21:41, 8 July 2011 (UTC)
The article has been modified so as to imply that pyrolysis applies only to organic substances. However the term seems to be used also for inorganic substances, e.g. "Yakubovich and coworkers obtained insoluble polymers [...] by the pyrolysis of phosphazene phosphoxides at 220°C." [1]. So I will restore the original wording "mainly used for organics" (but not exclusively). All the best, -- Jorge Stolfi ( talk) 22:55, 4 January 2010 (UTC)
The article states that pyrolysis is a special case of thermolysis. However, reading both articles, I could not find or imagine an example of thermolysis that is not a pyrolyis. In fact, the IUPAC Gold Book defines them as synonyms. http://goldbook.iupac.org/P04961.html and http://goldbook.iupac.org/T06326.html. Do you agree with that? 200.164.157.164 ( talk) 19:21, 14 April 2010 (UTC)
Pyrolysis is usually reported as a special case of thermolysis in review papers examining biomass as pyrolysis feedstock. I agree that coal for instance can be described as operated on by pyrolysis and thermolysis (with no difference at all?). If it is just a semantics issue, it'd be worth a note in the article about which scientific "cliques" use what term. I know torrefaction is usually considered a low temperature (200 celsius or less?) form of pyrolysis.
Hero of Ludi (
talk)
03:36, 17 August 2012 (UTC)
I expanded (actually rewrote) the Chemistry section to add more detail and improve the sense. I agreed with the original author, but just tried to add a little more detail from a personal survey of recent research. I neglected to add additional citations (I just left the original citation in place). I will add citations.
I also added a little more detail to the Biofuel section and linked out to biomass sources by name. I didn't add citations, but they could be added. Hero of Ludi ( talk) 03:40, 17 August 2012 (UTC)
I believe (but don't have refs) that laser-cutting of wood produces it's effect by pyrolysis. If that's correct, it would be a useful addition to the Examples section. SteveBaker ( talk) 20:10, 16 April 2013 (UTC)
Hello fellow Wikipedians,
I have just modified 3 external links on Pyrolysis. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit User:Cyberpower678/FaQs#InternetArchiveBot*this simple FaQ for additional information. I made the following changes:
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Cheers.— cyberbot II Talk to my owner:Online 21:48, 1 June 2016 (UTC)
"Using tires as fuel produce equal energy as burning oil and 25% more energy than burning coal.[23]"
This statement is meaningless. Tabby ( talk) 10:39, 1 August 2016 (UTC)
Today I removed this content. Unless one cooks like my grandmother, pyrolysis and the kitchen are not connected concepts. "Pyrolysis also plays an important role in several cooking procedures, such as baking, frying, grilling, and caramelizing.
Pyrolysis occurs whenever food is exposed to high enough temperatures in a dry environment, such as roasting, baking, toasting, or grilling. It is the chemical process responsible for the formation of the golden-brown crust in foods prepared by those methods.
In normal cooking, the main food components that undergo pyrolysis are carbohydrates (including sugars, starch, and fibre) and proteins. (See: Maillard reaction.) Pyrolysis of fats requires a much higher temperature, and, since it produces toxic and flammable products (such as acrolein), it is, in general, avoided in normal cooking. However, it may occur when one is grilling fatty meats over hot coals.
Even though cooking is normally carried out in air, the temperatures and environmental conditions are such that there is little or no combustion of the original substances or their decomposition products. In particular, the pyrolysis of proteins and carbohydrates begins at temperatures much lower than the ignition temperature of the solid residue, and the volatile subproducts are too diluted in air to ignite. (In flambé dishes, the flame is due mostly to combustion of the alcohol, while the crust is formed by pyrolysis as in baking.)
Pyrolysis of carbohydrates and proteins requires temperatures substantially higher than 100 °C (212 °F), so pyrolysis does not occur as long as free water is present, e.g., in boiling food — not even in a pressure cooker. When heated in the presence of water, carbohydrates and proteins suffer gradual hydrolysis rather than pyrolysis. For most foods, pyrolysis is usually confined to the outer layers of food, and begins only after those layers have dried out.
Food pyrolysis temperatures are, however, lower than the boiling point of lipids, so pyrolysis occurs when frying in vegetable oil or suet, or basting meat in its own fat.
Pyrolysis also plays an essential role in the production of barley tea, coffee, and roasted nuts such as peanuts and almonds. As these consist mostly of dry materials, the process of pyrolysis is not limited to the outermost layers but extends throughout the materials. In all these cases, pyrolysis creates or releases many of the substances that contribute to the flavor, color, and biological properties of the final product. It may also destroy some substances that are toxic, unpleasant in taste, or those that may contribute to spoilage.
Controlled pyrolysis of sugars starting at 170 °C (338 °F) produces caramel, a beige to brown water-soluble product widely used in confectionery and (in the form of caramel coloring) as a coloring agent for soft drinks and other industrialized food products.
Solid residue from the pyrolysis of spilled and splattered food creates the brown-black encrustation often seen on cooking vessels, stove tops, and the interior surfaces of ovens."-- Smokefoot ( talk) 01:29, 10 January 2018 (UTC)
This WP:UNDUE ("hippie science") was also removed. The article is about pyrolysis, not someone's dream for how if might make the world wonderful..."[Pyrolysis of plastics produces fuels] with a higher cetane value and lower sulphur content than conventional diesel.<ref>[http://www.zerowaste.sa.gov.au/upload/resource-centre/publications/waste-to-energy/Case%20Study%203%20Cynar%20Plastics%20to%20Fuel%20FINAL.pdf Cynar Plastics to Diesel]. Ricardo – AEA Ltd (2013)</ref> Using pyrolysis to extract fuel from end-of-life plastic is a second-best option after recycling, is environmentally preferable to landfill, and can help reduce dependency on fossil fuels and geo-extraction."
Long essay on biochar, which is tangential to this topic. Reads like a rant. "Biochar improves the [[soil structure|soil texture]] and [[ecology]], increasing its ability to retain fertilizers and release them slowly. It naturally contains many of the [[micronutrient]]s needed by plants, such as [[selenium]]. Biochar is also safer than other "natural" fertilizers such as animal [[manure]], since it has been [[disinfect]]ed at high temperature. And, since it releases nutrients at a slow rate, it greatly reduces the risk of [[water table]] contamination.<ref name='gardaus1'> {{cite news | first = Peter | last = Cundall | title = Fact Sheet: Pete's Patch | date = 2007-10-27 | publisher = Australian Broadcasting Corporation | url = http://www.abc.net.au/gardening/stories/s2071694.htm | work = Gardening Australia | accessdate = 2008-07-10}}</ref> Biochar is also being considered for [[carbon dioxide sink|carbon sequestration]], with the aim of [[mitigation of global warming]].<ref name='horstman1'> {{cite news | first=Mark | last=Horstman | title=Agrichar – A solution to global warming? | date=2007-09-23 | publisher=Australian Broadcasting Corporation | url =http://www.abc.net.au/catalyst/stories/s2012892.htm | work =ABC TV Science: Catalyst | accessdate = 2008-07-10 }} </ref><ref> {{cite news |url=http://news.bbc.co.uk/1/hi/england/7993034.stm |title=Trial to reverse global warming |publisher=BBC News |accessdate=2009-04-21 | date=2009-04-09}} </ref><ref> {{cite news |url=http://www.economist.com/sciencetechnology/displaystory.cfm?story_id=14302001 |title=The virtues of biochar: A new growth industry? |date=2009-08-27 |publisher=The Economist |accessdate=2009-08-30 }} </ref> The solid, carbon-containing char produced can be sequestered in the ground, where it could remain for several hundred to a few thousand years.<ref>[http://www.biochar-international.org/biochar/faqs#q9 Frequently Asked Questions about Biochar | International Biochar Initiative]. Biochar-international.org (2013-04-19). Retrieved on 2013-06-01.</ref> Research continues about the processes responsible for long-term sequestration of carbon in soils.<ref>{{Cite journal|last=Schmidt|first=Michael W. I.|last2=Torn|first2=Margaret S.|last3=Abiven|first3=Samuel|last4=Dittmar|first4=Thorsten|last5=Guggenberger|first5=Georg|last6=Janssens|first6=Ivan A.|last7=Kleber|first7=Markus|last8=Kögel-Knabner|first8=Ingrid|last9=Lehmann|first9=Johannes|date=2011-10-06|title=Persistence of soil organic matter as an ecosystem property|url=http://www.nature.com/nature/journal/v478/n7367/abs/nature10386.html|journal=Nature|language=en|volume=478|issue=7367|pages=49–56|doi=10.1038/nature10386|issn=0028-0836|bibcode=2011Natur.478...49S}}</ref>"
-- Smokefoot ( talk) 14:38, 10 January 2018 (UTC)
"Neanderthals used pyrolysis of birch bark to produce a pitch with which they secured flaked stones to spear shafts.<ref>[https://www.pbs.org/wgbh/nova/evolution/defy-stereotypes.html NOVA – Official Website | Neanderthals Defy Stereotypes]. Pbs.org. Retrieved on 2016-12-16.</ref> Recently, researchers have developed a process to pyrolyze birch bark to produce an oil that can replace [[phenol]] in [[phenol formaldehyde resin]] (these resins are mostly used to manufacture [[plywood]]).<ref>Dongbing Li, Franco Berruti, Cedric Briens, "Autothermal fast pyrolysis of birch bark with partial oxidation in a fluidized bed reactor", Fuel, Volume 121, 1 April 2014, Pages 27–38</ref>" removed as tangential.-- Smokefoot ( talk) 14:48, 10 January 2018 (UTC)
I'm reasonably smart and sciencey and stuff but I have no idea what is going on in the graphic that is labeled "Simplified depiction of pyrolysis chemistry". I respectfully suggest it needs a really good descriptive caption or it should be eliminated. Kirkpete ( talk) 23:32, 28 February 2019 (UTC)
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This article was the subject of a Wiki Education Foundation-supported course assignment, between 24 August 2022 and 9 December 2022. Further details are available on the course page. Student editor(s): 07JOS ( article contribs).
— Assignment last updated by 07JOS ( talk) 18:19, 1 December 2022 (UTC)