Talk:Pyrolysis

message: :::::::::::: (added in retrospect)--Tunheim 19:10, 3 February 2007 (UTC)
thread_title:  Uncategorized 

message: 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)
thread_title: Section on Bio-oil?

message: 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)
thread_title: Anhydrous pyrolysis

message: 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)
thread_title: Waste pyrolysis

message: 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)
replies: text: The strictest definition is that contained in the very term pyrolysis: decomposition or dissolution (lysis) by intense heat or by fire (pyros, both from Greek).  When it comes to organics, of course, the absence of O2 is in most cases a must so that oxidation or combustion are not the main reactions.  So you are partially right.--Unconcerned 08:05, 7 December 2005 (UTC)
replies: text: Hmm. I don't understand your meaning.  If you are trying to eliminate surface contaminants, do you really care if those contaminants are oxidized or combusted? ike9898 14:43, 7 December 2005 (UTC)
replies: text: Well, the term might be used in some cases as a fancy substitute for burning, but the chemical reaction/process of pyrolysis is fundamentally different from a combustion process in that the reactant molecules are fragmented without any incorporation of new atoms.  It'd be nice though if you could include in the article the specific usage you say you're aware of.--Unconcerned 05:23, 8 December 2005 (UTC)

text: I'd say this is an example of mis-use of the word. Simple and easy :P --Tunheim 19:13, 3 February 2007 (UTC)
thread_title:  Term used more loosely? 

message: 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)
replies: text:  The "what links here" for Pyrolysis and Destructive Distillation look pretty similar in application and context to me. Can you explain what the difference between Pyrolysis and Destructive Distillation is?  Toiyabe 01:22, 23 February 2006 (UTC)
replies: text:  pyrolysis in the laboratory is actually used in organic synthesis particularly radical chemistry and rearrangements. Destructive Distillation is an industrial process. V8rik 17:56, 23 February 2006 (UTC)
replies: text:  I am no chemist, but I would guess that "Destructive distillation" (DD) is generally used for industrial processes, and implies that the distilled phases are condensed and used; whereas pyrolysis is a geeneral chemical process, that may happen in any settings (including by accident) and does not imply recovery or use of the byproducts. So DD uses pyrolysis, but there is much pyrolysis that is not DD. Makes sense? Jorge Stolfi 12:51, 23 February 2006 (UTC)
replies: text:  OK, I can live with that.  To be consistent, a lot of the links to pyrolysis should be moved to DD.  DD and pyrolysis should include text that explains the distinction. Toiyabe 16:50, 23 February 2006 (UTC)

text: To me dry distillation and destructive distillation seems to be the same thing. It has been previously stated in the discussion thread of both articles that they are not the same thing (A B). However no explanation or references has been given to back up the statement. Would someone care to explain the difference? Please reply at destructive distillation talk page. --Alf 09:33, 22 December 2006 (UTC)
thread_title:  Merge? 

message: 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 think they are important examples of pyrolysis being part of an industrial/chemical  process. Just like an ion transfer or a reduction might be part of a more complex chemical process. As long as we make it clear that the pyrolysis is fueled by the heat from the combustion. So in my opinion it's a good example, but it might be possible to write it better. --Alf 09:42, 22 December 2006 (UTC)
thread_title:  Pyrolysis with charcoal production and coke production? 

message: Presently (http://en.wikipedia.org/w/index.php?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)
thread_title:  Link spam 

message: 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
* probably remove some detail about biochar, i don't want to lose material thought, so this might be transferred to biochar if it is not already duplicated there
* maybe too much info still in "4. Processes for biomass pyrolysis"? David Woodward 08:22, 28 October 2007 (UTC)
thread_title: more to do

message: 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)
thread_title: Comment

message: 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)
replies: text: Agreed, I didn't expect to come here either 87.194.30.190 (talk) 21:47, 8 May 2009 (UTC)
replies: text:  In the research field, we call it either bio-oil of pyrolysis oil. Kind of like "Kleenex" has come to be the name of nose-tissues. If it really bothers you, go ahead and change all references to "bio-oil" to "pyrolysis-oil" (or "py-oil"). PyrolysisGenius (talk) 23:19, 25 June 2012 (UTC)
thread_title:  "bio-oil" redirect 

message: 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)
thread_title:  Carcinogens 

message: 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." . 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)
thread_title:  Pyrolysis or non-organic materials 

message: 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)
replies: text: Yes! The pages ought to be the same. However, thermolysis has colloquially come to be more broad (temperature-wise), including gasification and torrefaction as well. I don't know why, though. PyrolysisGenius (talk) 23:21, 25 June 2012 (UTC)
thread_title:  Same as Thermolysis? 

message: 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)
thread_title: Chemistry and Biofuel sections edit

message: 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)
thread_title:  Laser cutting. 

message: Hello fellow Wikipedians,
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thread_title:  External links modified 

message: "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)
thread_title: Energy claim

message: === Cooking ===
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 , 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  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)
thread_title: Edits of Jan 2018

message: 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 , 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  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)
thread_title:  Cooking 

message: 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.Cynar Plastics to Diesel. Ricardo – AEA Ltd (2013) 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 texture and ecology, increasing its ability to retain fertilizers and release them slowly. It naturally contains many of the micronutrients needed by plants, such as selenium. Biochar is also safer than other "natural" fertilizers such as animal manure, since it has been disinfected at high temperature. And, since it releases nutrients at a slow rate, it greatly reduces the risk of water table contamination.
  
Biochar is also being considered for carbon sequestration, with the aim of mitigation of global warming.
  




 The solid, carbon-containing char produced can be sequestered in the ground, where it could remain for several hundred to a few thousand years.Frequently Asked Questions about Biochar | International Biochar Initiative. Biochar-international.org (2013-04-19). Retrieved on 2013-06-01. Research continues about the processes responsible for long-term sequestration of carbon in soils."
--Smokefoot (talk) 14:38, 10 January 2018 (UTC)
thread_title: Biofuels angle

message: "Neanderthals used pyrolysis of birch bark to produce a pitch with which they secured flaked stones to spear shafts.NOVA – Official Website | Neanderthals Defy Stereotypes. Pbs.org. Retrieved on 2016-12-16. 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).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" removed as tangential.--Smokefoot (talk) 14:48, 10 January 2018 (UTC)
thread_title: Neanderthal's adhesives

message: 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)
thread_title:  Top graphic needs elaboration 

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thread_title:  A Commons file used on this page or its Wikidata item has been nominated for deletion 

message: — Assignment last updated by 07JOS (talk) 18:19, 1 December 2022 (UTC)
thread_title: Wiki Education assignment: Environmental Chemistry