Talk:Combustion

nitrogen hydrocarbon combustion?

Is the stöchiometric combustion for hydrocarbons containing nitrogen known? For example for Pyridin. Is NO2 or NO or N2 the stöchiometric product? — Preceding unsigned comment added by 129.70.70.122 (talk) 11:33, 6 October 2011 (UTC)

Respiration

I don't think respiration should be included in this page. I thought the definition of "combustion" was rapid oxidation, so by definition there can't be "slow combustion". --Keenanpepper 01:28, 14 Oct 2004 (UTC)

Speed has nothing to do with whether combustion occurs or not, it has to do with what the reactants are. As long as you have a hydrocarbon reacting with oxygen which is creating carbon dioxide, and sometimes carbon monoxide and/or water as well, you have combustion. Respiration is O₂ reacting with the various forms of carbon in an organism, and it creates CO₂ as a result. Therefore, by definition, it is combustion. --BMS 03:47, 16 Dec 2004 (UTC)

The definition of combustion does not include a reference to speed. Within the frame work of combustion - there is no such thing as 'slow' combustion -or 'rapid' combustion. There are rates of combustion which are relative. —Preceding unsigned comment added by 64.30.82.123 (talk) 02:26, 4 October 2009 (UTC)

But the definition states combustion is accompanied by the production of heat or both heat and light in the form of either a glow or flames.I do not believe this happens in respiration (except fot the inevitable increase in entropy). Is the definition not accurate then? Manuel N —Preceding unsigned comment added by 84.120.147.37 (talk • contribs) 7 December 2006 (UTC)

Spontaneous Combustion

The spontaneous combustion page disambiguates to this page and this page has a link to spontaneous combustion but neither actually describes what it is or how it works. Which should contain information or should a third page be created?

I think that someone should add to this page, under "types" of combustion. Bernard S. Jansen 04:14, 15 January 2007 (UTC)

I think that any section of Spontaneous Combustion should be separated from the established Combustion pages, and every section in there should be well sourced. IOW I think Spontaneous Combustion is right up there with Vampires and Werewolves, and deserves no place here. —Preceding unsigned comment added by Halligan00 (talk • contribs) 14:24, 6 February 2009 (UTC)

Factual error

This was a dispute over the inclusion of N2 in the equation of complete combustion since it doesn't react. It was decided it should be kept since it affects the temperature and does react to make minor species. Full details are in the Combustion Archive.

Example

in the example in the intro carbon is made a link in the reaction. Why? It is no more relevant than the other elements. Ozone 00:34, 1 January 2006 (UTC)

Improvements needed

This was a dispute that spawned from confusion over different terminology meaning the same thing, particular adiabatic combustion temperature with adiabatic flame temperature and heat of combustion with heating value. It was decided that a more conscious effort should be made to include multiple terminology but to also to point the terms are equivalent. Full details are in the Combustion Archive.

Formation of formaldehyde

Formaldehyde says that it can be formed by incomplete combustion. What kind of reaction would result in formaldehyde? Just taking a wild stab in the dark with methane:

$C H_4 + O_2 \to H_2 C O + H_2 O + heat$

I have no idea if that's a valid reaction but the elements at least are equal on both sides... Cburnett 05:02, 11 April 2006 (UTC)

The primary source of Formaldehyde in a steady flame is the reaction between the methyl and oxygen radical shown below.

$CH_3 + O \to CH_2O + H$

There are other reactions that'll make Formaldehyde but their rate of reaction are orders of magnitude lower. The most important of these are two reactions that are dominant during the ignition process because the concentration of the oxygen radical hasn't built up yet.

$CH_3O + M \to CH_2O + H + M$

$CH_3O + O_2 \to CH_2O + HO_2$

boy that is complicated--Kkidd (talk) 14:55, 18 May 2008 (UTC)

For the sake of completeness there is one more worth mentioning but it is the slowest of the four.

$CH + H_2O \to CH_2O + H$

BlatantHeroics 00:05, 24 June 2007 (UTC)

Combustion Analysis ?

In the short section called "Combustion Analysis", it is defined as the determination of the compounds created by combustion. Though, I added a link to a page called "Combustion Analysis" regarding -mainly- the application of exhaust fume analysis to the determination of combustion efficiency. We have here two different fields related to the same term: theory of chemistry and empirical thermal engineering. Does anyone can help to get an agreement on the definitions ? Kekel 20:04, 20 April 2006 (UTC)

Kekel, I really don't see any major difference. Combustion analysis (what you call "theory of chemistry") involves combusting an organic compound, analyzing the products of combustion and then using that information to determine the formula of the organic compond. The combustion link you added also analyzes the products of combustion and then uses that information to determine the quality of the combustion.

Both procedures involve combustion and analyzing the products of combustion. Both use that information to find additional useful information. I really don't see that as a conflict between "theory of chemistry" and "empirical thermal engineering". Nor do I understand why you labeled the boiler usage as "empirical". It is no more or no less empirical than the other usage. -mbeychok 18:23, 21 April 2006 (UTC)

Still, one approach is qualitative (the "chemistry" one) and the other is more quantitative (the "engineering one"). It makes a difference in my mind. But no big deal probably. The real thing is it would be nice if this section, "combustion analysis", could be developed in one way or another. Actually, I don't have the basics for this. I only entered the field cause I was looking for some info for my work that I finally found through this link.

Kekel 21:46, 23 April 2006 (UTC)

not really interested in the debate between chemistry related analysis vs. engineering related analysis- but I included a small section about combustion analysis at the end of the incomplete combustion section- where it applies practically?johntindale (talk) 15:55, 14 May 2008 (UTC)

Reverting of Pvsheridan's comment about fossil fuels

Pvsheridan had entered a paragraph in the Combustion Analysis stating that the term "fossil fuel" was a misnomer and that Wikipedia should completely remove that misnomer from all its articles. His reasoning was that "recent finds" made it obvious that the more correct term was "hydrocarbon fuels" ... presumably because hydrocarbon fuels did not originate from fossilized animals. He failed to furnish any source references or proof of his contention.

Since the term "fossil fuel" exists in a very great many Wikipedia articles and probably hundreds of thousands of books, magazines, journals, encyclopedias and web sites, that is a pretty drastic step that Pvsheridan is asking for. It really doesn't belong in any section of this article. I suggest that he/she make his proposal at the Wikipedia Village Pump. For that reason, I removed his paragraph from this article by reverting to the previous version. - mbeychok 22:16, 23 April 2006 (UTC)

No mention of radicals?

Why are free radicals not mentioned anywhere in this article? Aren't they necessary for the survival of a flame?--Joel 19:46, 6 June 2006 (UTC)

Yes, it should definitely be mentioned that the mechanism of a combustion reaction (at least when oxygen is a reactant) is via radicals. There is an good section on combustion in the radical article that should be integrated into this page. --Tospik 23:37, 24 July 2007 (UTC)

Hydrocarbons

Should this be expanded to cover combustion of eg alcohols, alkenes, etc. Joseph Sanderson 17:16, 8 October 2006 (UTC)

addition

would it be possible for somebody to add information about elemental impurities during combustion affecting what the products are? Although a few elements, such as sulfur and iron, were mentioned, I think that should be expanded to include a more general discussion of the combustion of other elements, like maybe silicon, or phosphorus, or boron. 65.78.17.194 20:22, 13 October 2006 (UTC)

Could we add information about DUST COMBUSTION to this entry??? —Preceding unsigned comment added by 68.58.152.238 (talk) 21:15, 28 November 2008 (UTC)

Away from the basics

Does anyone understand what characteristic of oxygen makes combustion happen? What is it about reactions with that specific element that makes fire? How does that attribute work which makes it different from any other reaction that is not combustion? I'd appreciate any input. Thank you.

double replacement vs. single replacement.... and plasma

Could someone please explain the difference between 'double replacement' and 'single replacement' in the following sentence? They aren't linked to another document to explain them: Combustion is double replacement, on the other hand a chemical reaction is single replacement.

Also, it would be great if someone would go into more detail about how and when fire/combustion is like a plasma (either on the combustion page, or the fire page).

Thanks!

Isabelle Hakala 04:11, 19 April 2007 (UTC)

Heat of Combustion of Sulfur

What is the heat of combustion of sulfur? Here it is listed at 9261 kJ/kg which is equal to 3982btu/#, but on the "Heat of Combustion" entry it is listed at 4.639MJ/kg, which is 1995 btu/#.... —Preceding unsigned comment added by 74.0.223.151 (talk) 13:33, 11 September 2007 (UTC)

The value given in this article is for solid sulfur and is correct. The value in the Heat of combustion article is incorrect and I have corrected it. - mbeychok 20:17, 11 September 2007 (UTC)

Combustion

Combustion is made when a complex sequence of axothermic chemical reactions betwwen a fuel and an oxidant ccompanied by the production of heat or both heat and ligh in the form of either a glow or flame. In other words its a specific reaction that happends wen there a chemical bond. When these 2 chimicals bond and form a combustion it usually oxidises. —Preceding unsigned comment added by 72.187.134.27 (talk) 03:28, 31 October 2007 (UTC)

Not all exothermic reactions should be considered combustion. For example, when carbon and hydrogen react to form methane, heat is evolved, but I don't think anybody regards this as "combustion". And when oxygen is added to methane to form methanol, calling this combustion pushes the term to a point where it's meaning becomes too diffuse to be useful.Thermbal 05:34, 9 November 2007 (UTC)

Indeed, and rusting is another one. Can we tighten up the definition to exclude these cases? 88.96.214.6 (talk) —Preceding undated comment added 17:49, 21 December 2009 (UTC).

Please see my comments under the header "Definition" I'll appreciate your comments. —Preceding unsigned comment added by 67.253.165.162 (talk) 19:01, 1 December 2010 (UTC)MK67.253.165.162 (talk) 16:45, 1 December 2010 (UTC)

What Chemicals was released?

During the burning of slate dumps there where chemicals relased from these burning slate dumps, Does anyone know what the chemicals was in English terms and was it toxic? —Preceding unsigned comment added by 75.108.161.89 (talk) 15:13, 15 February 2008 (UTC)

What causes heat to burn things?

Since this is an article that is primarily scientific in nature, I thought someone here might be able to answer it. What is it that causes fire and heat to burn other things. And I mean this on a molecular level. I really have no clue myself, yet it's the only question I've ever had about anything that I couldn't find on the internet. Does it have something to do with the speed that molecules of fire/heat are moving and when this hits say the molecules of something like wood or flesh it separates them or something? Another example would be lasers. Some lasers are fine to hit other objects, they have no visible effect. However a more intense/powerful laser will burn through very hard substances. What is the intense laser actually doing to the substance at a molecular level that the weaker laser isn't. Livingston 00:02, 18 September 2008 (UTC)

You'll probably get more answers if you post this question at Wikipedia:Reference desk/Science. That page is watched by more people, many of whom are eager to answer interesting questions such as this one. --Itub (talk) 18:05, 18 September 2008 (UTC)

I did try to answer the question in the reaction mechanism section. Obviously any unclear parts could be clarified, as it isn't always obvious to the writer what parts are too difficult to dereference (or too obscure or wordy). --Vuo (talk) 20:35, 18 September 2008 (UTC)

A reference in the at the end of title of the reaction mechanism section, linking to the "radicals" article could be helpful.67.253.165.162 (talk) 18:59, 1 December 2010 (UTC)MK

The lead

it is bad, rm all equations to start with? --Vuo (talk) 18:29, 13 January 2009 (UTC)

Vuo, with all due respect, I completely disagree with you. There is no good reason why all of the equations (or any of them) should be removed from the lead section. Nor do I believe that the the lead is "bad". regards, mbeychok (talk) 02:31, 14 January 2009 (UTC)

Possible typo

In the section titled "Reaction mechanism", hydroperoxl is mentioned and is given the formula "OH₂". Isn't hydroperoxyl actually HO₂ ? At least this is what the wiki article on hydroperoxyl says. (Also, wouldn't OH₂ be the same as H₂O?).

TinyTimZamboni (talk) 01:52, 11 June 2009 (UTC)

• I read "OH₂" as water! Agreed. Bridgettttttte (talk) 11:13, 22 May 2010 (UTC)

combustion

what are the advantages and disadvantages of combustion? —Preceding unsigned comment added by 121.7.77.25 (talk) 14:56, 19 July 2009 (UTC)

Definition

Several comments above have gotten at the issue, but without a clear answer. What definition of combustion is being used here? Is it "any oxidation-reduction reaction that is exothermic"? That seems rather broad. 68.239.116.212 (talk) 03:04, 7 December 2009 (UTC)

I agree with the original posting of the question (i.e. "what definition is being used here?") that any oxidation acompanied by release of heat is a rather broad definition. Expert books on combustion I browsed through do not define conbustion clearly, and quickly move on to topics of practical interest, which always involves organic fuels decomposing into other organic substances, many also fuels, which are gaseous under the conditions surrounding the reaction site. It seems to me that a practical definition should include the idea of the the presence of gas products that can transmit significant heat by convection. The intense light of a flash, for example, would be excluded as a "combustion" in that case. 67.253.165.162 (talk) 19:00, 1 December 2010 (UTC)MK67.253.165.162 (talk) 18:42, 1 December 2010 (UTC) —Preceding unsigned comment added by 67.253.165.162 (talk) 16:41, 1 December 2010 (UTC)

Elements supporting combustion

If my understanding that there are only a few substances that support combustion is correct, would it be worth naming them explicitly ?

Currently Oxygen & Flourine are mentioned.

According to <a href="http://sg.answers.yahoo.com/question/index?qid=20081228055613AA3jAcl">this forum post</a>, two more are mentioned. The author also makes the distinction that although Nitrous oxide (and a few other substances containing oxygen) are often said to support combustion, they are in fact oxidants. —Preceding unsigned comment added by ThermalCat (talk • contribs) 12:12, 8 January 2010 (UTC)

Combustion

It is the sequence of exothermic reactions between a fuel and an oxident accompanied by the production of heat and conversion of chemical species.The release of heat can result in the production of light in the form of either glowing or a flame.Most fuels of interest are organic compounds ( especially hydrocarbon) in the gas, liquid or solid phase. —Preceding unsigned comment added by 217.42.215.160 (talk) 16:23, 2 February 2010 (UTC)

I agree with the original posting of the question (i.e. "what definition is being used here?") that any oxidation acompanied by release of heat is a rather broad definition. Expert books on combustion I browsed through do not define conbustion clearly, and quickly move on to topics of practical interest, which always involves organic fuels decomposing into other organic substances, many also fuels, which are gaseous under the conditions surrounding the reaction site. It seems to me that a practical definition should include the idea of the the presence of gas products that can transmit significant heat by convection. The intense light of a flash, for example, would be excluded as a "combustion" in that case.67.253.165.162 (talk) 19:01, 1 December 2010 (UTC)MK

I would think the production of light or a flame would be a requirement for a reaction to be considered combustion. It seems to me that if light or a flame is not a requirement for a combustion reaction, the definition might as well be an exothermic oxidation reaction.24.14.162.203 (talk) 00:17, 5 June 2011 (UTC)

Reaction Mechanism Section starts off too advanced

Concepts involving singlet and triplet states are at the level of third-year college chemistry, typically a physical chemistry class or a class in molecular orbital theory for chemistry majors. A far simpler explanation is to describe diatomic oxygen as a molecule bonding two electronegative atoms, wheareas in combustion products the oxygen atoms are bonded to more electropositve elements such as hydrogen and carbon. Bridgettttttte (talk) 11:09, 22 May 2010 (UTC)

Thioformaldehyde Combustion

I think the beginning paragraph should make mention of the reactants (fuel) (i.e. For example: should be For example the combustion reactions of methane and of thioformaldehyde) —Preceding unsigned comment added by MarsInSVG (talk • contribs) 18:28, 24 August 2010 (UTC)

Solid Fuels

The text under the Solid Fuels heading sounds like an apt description of how cellulose (e.g., wood, paper, cardboard) burns, but it is not fully applicable to other solid substances (e.g., hexamine) burn. Hexamine, for example, does not burn in a "charcoal phase," and charcoal–a solid fuel in its own right–does not burn in a "distillation phase." 71.199.121.113 (talk) 19:16, 3 September 2010 (UTC)

Typo regarding Nitrogen

In the "Complete vs. incomplete" section:

"Nitrogen does not take part in combustion, but at high temperatures, some nitrogen will be converted to NOx, usually between 1% and 0.002% (2 ppm)."

One of those figures (0.002% and 2 ppm) has to be wrong, because...

0.002% would be 20 ppm.

0.0002% would be 2 ppm.

I would change it myself but I don't know which figure is the correct one, and having no luck searching online.

Ignition

I am surprised that there is not a topic (or indeed separate article) on ignition, and ignition temperature. Such an addition would be appreciated. ColinBJ (talk) 14:26, 9 February 2011 (UTC)

There is an article on Ignition system but not a separate article on ignition or ignition temperature. Wikipedia is still a work in progress. There are many worthy articles waiting to be written. Are you able to write such an article? Even it is just the beginning of an article - they are called stubs. Here is a link to some good information that will assist you in beginning an article on these subjects:

• How to write a great article
  

Happy editing! Dolphin (t) 21:31, 9 February 2011 (UTC)

I have found there is an article on 'autoignition temperature' which has most of what I'm thinking of. What's needed is a cross-reference to it in the combustion section, and also to redirect searches for 'ignition' to it. ColinBJ (talk) 06:19, 20 February 2011 (UTC)

Done. Searching for Ignition temperature now re-directs to the article Autoignition temperature. Check it out by selecting the following: Ignition temperature. Dolphin (t) 06:29, 20 February 2011 (UTC)

Thioformaldehyde?

Since 20 July 2005, this article has had the equation for the oxidation of thioformaldehyde, CH₂S, by fluorine, F₂: CH₂S + 6 F₂ → CF₄ + 2 HF + SF₆. Is this reaction, which was in the article before the equation for the combustion of methane, relevant to an encyclopedia article of on combustion?

Thioformaldehyde, is apparently an unstable compound. It is stable as its heterocyclic trimer, 1,3,5-Trithiane. If CH₂S is unstable, does it last long enough for a meaningful "combustion" reaction to occur? Is there an application for this reaction with fluorine that could be deemed "combustion."

Interestingly, an internet search on "CH2S + 6 F2 → CF4 + 2 HF + SF6" gives many, many links.[1],[2],[3], [4],[5]

I don't know if the information started here, but it seems to spread quickly. Here is your chance to defend the equation in this article.KudzuVine (talk) 23:25, 14 September 2011 (UTC)

• No discussion in three months. I will take it out.KudzuVine (talk) 15:33, 23 December 2011 (UTC)

Just trying to help, think I found a type in fuel does not burn rapidly and just glows and later only

The text said: fuel does burn rapidly and just glows and later only

I tried to change it to fuel does not burn rapidly and just glows and later only--notice the inclusion of "not"

That was because I thought that is what the author meant.

I don't really understand how to contribute, or discuss, and am assuming somebody will delete this section I just created after deciding of the "not" should be included. — Preceding unsigned comment added by 173.57.19.120 (talk) 12:59, 19 November 2011 (UTC)

Nitrogen

In the last reaction with nitrogen? isnt the nitrogen already balanced? then why is it part of the equation? the equation starts with some other elements +N(2) and after the chemical reaction, some other elements + the same N(2)is produced. This doesnt make any sense.

It is there to show that during combustion in air, the oxygen reacts, but the nitrogen does not. It is present in the reaction mixture, and present unchanged in the product mixture. I agree that this intention may not be readily apparent, so if there is a way that anyone can help clarify the text for the average reader, that would be helpful. -- Ed (Edgar181) 14:46, 1 March 2012 (UTC)

It should also be notes that the "air" in the left-hand side of the equation is composed of oxygen and nitrogen. All of the oxygen is consumed in the reaction, but none of the nitrogen is consumed since it is non-combustible. mbeychok (talk) 16:00, 1 March 2012 (UTC)