why does a clean flame produce soot?

[Colt45]

for example, light a butane lighter under a piece of glass.
the glass will get black soot (carbon??) on it.

i thought a butane flame is fairly pure.. why does it produce this soot?

any ideas?

thanks

 

[gopunk]

i think it's a reaction on the glass' part, not that the flame is depositing something.

 

[FrontlineWarrior]

i dunno but it's not oxidation

 

[FrontlineWarrior]

has nothing to do with glass. the soot comes from whatever stuff (impurities or whatever) is involved in the combustion.

 

[Colt45]

hmmm.. well im just using glass as an example.. it could be anything though..
ceramic, aluminum, etc. they all do it for me..

and ive never had a technical explanation, so im just curious

 

[Jerboy]

<< for example, light a butane lighter under a piece of glass.
the glass will get black soot (carbon??) on it.

i thought a butane flame is fairly pure.. why does it produce this soot?

any ideas?

thanks >>




The flame looks orange, because small soot particles are emitting incandescent glow. The particles will burn off, but when exposed to cool surface, it deposits there.

Give it more oxygen and you wouldn't get soot and you'll have blue flame.(natural gas stove, oxyacetylene torch with sufficient O2)

 

[FrontlineWarrior]

interesting pics

 

[FrontlineWarrior]

interesting page

 

[aphex]

pretty cool page

 

[nirgis]

the combustion of any hydrocarbon may result in the following products: carbon dioxide, carbon monoxide, or carbon (soot). Which product is produced is directly dependent on the amount of oxygen present. Thus, in every combustion there is a varying amount of soot, dependent on the oxygen levels

 

[Jerboy]

<< the combustion of any hydrocarbon may result in the following products: carbon dioxide, carbon monoxide, or carbon (soot). Which product is produced is directly dependent on the amount of oxygen present. Thus, in every combustion there is a varying amount of soot, dependent on the oxygen levels >>




and various other chemicals..


Anyone ever noticed a pungent odor from natural gas appliance for a few sec immediately after ignition? When cold, some of the natural gas turns into formaldehyde. It is more noticeable in presence of catalyst such as platinum.

Have you operated an engine powered RC stuff? Then I'm pretty sure you know that pungent smelling exhaust when engine is idling.