[hamdani yusuf]

PLWASE JUST FIND OUT WHAT "FLASH POINT" MEANS!

Since you asked politely,

First entry of google search :
The flash point is the lowest temperature at which a volatile substance evaporates to form an ignitable mixture with air in the presence of an igneous source and continues burning after the trigger source is removed.

If you think you have a better definition, please let me know. What makes you think that it's better than google's answer above?

[eric2011 (OP)]

Thanks Bored Chemist. I have learned so much from you

[Bored chemist]

If you think you have a better definition, please let me know. What makes you think that it's better than google's answer above?

I didn't ask you to quote it, I asked you to understand it.

Once you do, you will be able to answer your own questions about it.
I keep making this point- you should try leaning science.

[hamdani yusuf]

I didn't ask you to quote it, I asked you to understand it.

How would you know when I understand it?

[hamdani yusuf]

Once you do, you will be able to answer your own questions about it.
I keep making this point- you should try leaning science.

How would I know if my understanding is correct?
I also suggest you to keep learning science.

[Bored chemist]

How would I know if my understanding is correct?

Because you believe nonsensical claims that you read on the internet- such as the idea that charcoal has a flash point.

[Bored chemist]

How would you know when I understand it?

Because you would apologise for your absurd mistake.

[Bored chemist]

The flash point is the lowest temperature at which a volatile substance evaporates to form an ignitable mixture with air

Does charcoal evaporate at 40C (or even at 400C)?

[hamdani yusuf]

The flash point is the lowest temperature at which a volatile substance evaporates to form an ignitable mixture with air

Does charcoal evaporate at 40C (or even at 400C)?

https://www.fao.org/3/x5328e/x5328e0b.htm#10.1.2.%20volatile%20matter%20other%20than%20water

The volatile matter other than water in charcoal comprises all those liquid and tarry residues not fully driven off in the process of carbonization. If the carbonization is prolonged and at a high temperature, then the content of volatiles is low. When the carbonization temperature is low and time in the kiln is short, then the volatile matter content increases.

These effects are reflected in the yield of charcoal produced from a given weight of wood. At low temperatures (300°C) a charcoal yield of nearly 50% is possible. At carbonization temperatures of 500-600°C volatiles are lower and retort yields of 30% are typical. At very high temperatures (around 1000°C) the volatile content is almost zero and yields fall to near 25%. As stated earlier, charcoal can reabsorb tars and pyroligneous acids from rain wash in pit burning and similar processes. Thus the charcoal might be well burned but have a high volatile matter content due to this factor. This causes an additional variation in pit burned charcoal in wet climates. The resorbed acids make the charcoal corrosive and lead to rotting of jute bags - a problem during transport. Also it does not burn cleanly.

The volatile matter in charcoal can vary from a high of 40% or more down to 5% or less. It is measured by heating away from air, a weighed sample of dry charcoal at 900°C to constant weight. The weight loss is the volatile matter. Volatile matter is usually specified free of the moisture content, i.e. volatile matter - moisture or (V.M. - moisture).

High volatile charcoal is easy to ignite but may burn with a smoke flame. Low volatile charcoal is difficult to light and burns very cleanly. A good commercial charcoal can have a net volatile matter content - (moisture free) of about 30%. High volatile matter charcoal is less friable than ordinary hard burned low volatile charcoal and so produces less fines during transport and handling. It is also more hygroscopic and thus has a higher natural moisture content.

[Bored chemist]

The flash point is the lowest temperature at which a volatile substance evaporates to form an ignitable mixture with air

Does charcoal evaporate at 40C (or even at 400C)?

https://www.fao.org/3/x5328e/x5328e0b.htm#10.1.2.%20volatile%20matter%20other%20than%20water

The volatile matter other than water in charcoal comprises all those liquid and tarry residues not fully driven off in the process of carbonization. If the carbonization is prolonged and at a high temperature, then the content of volatiles is low. When the carbonization temperature is low and time in the kiln is short, then the volatile matter content increases.

These effects are reflected in the yield of charcoal produced from a given weight of wood. At low temperatures (300°C) a charcoal yield of nearly 50% is possible. At carbonization temperatures of 500-600°C volatiles are lower and retort yields of 30% are typical. At very high temperatures (around 1000°C) the volatile content is almost zero and yields fall to near 25%. As stated earlier, charcoal can reabsorb tars and pyroligneous acids from rain wash in pit burning and similar processes. Thus the charcoal might be well burned but have a high volatile matter content due to this factor. This causes an additional variation in pit burned charcoal in wet climates. The resorbed acids make the charcoal corrosive and lead to rotting of jute bags - a problem during transport. Also it does not burn cleanly.

The volatile matter in charcoal can vary from a high of 40% or more down to 5% or less. It is measured by heating away from air, a weighed sample of dry charcoal at 900°C to constant weight. The weight loss is the volatile matter. Volatile matter is usually specified free of the moisture content, i.e. volatile matter - moisture or (V.M. - moisture).

High volatile charcoal is easy to ignite but may burn with a smoke flame. Low volatile charcoal is difficult to light and burns very cleanly. A good commercial charcoal can have a net volatile matter content - (moisture free) of about 30%. High volatile matter charcoal is less friable than ordinary hard burned low volatile charcoal and so produces less fines during transport and handling. It is also more hygroscopic and thus has a higher natural moisture content.

Was that a yes or a no?
I suspect that you just cut and pasted something because you don't understand it well enough to answer the question.

[hamdani yusuf]

Was that a yes or a no?

The article tells that a charcoal is not a homogenous chemical substance. It contains volatile parts which are easier to evaporate than the solid part.
Your question is like asking if a wet cloth evaporates at 40C.

[Bored chemist]

Was that a yes or a no?

The article tells that a charcoal is not a homogenous chemical substance. It contains volatile parts which are easier to evaporate than the solid part.
Your question is like asking if a wet cloth evaporates at 40C.

No.
It is like asking if a wet cloth evaporates at -40C.

[hamdani yusuf]

Do you accept that powdered charcoal forms an ignitable mixture with air in the presence of an igneous source and continues burning after the trigger source is removed?

[Bored chemist]

Do you accept that powdered charcoal forms an ignitable mixture with air in the presence of an igneous source and continues burning after the trigger source is removed?

If it's hot enough, yes.
Obviously it does.
Do you think that is due to formation of "charcoal vapour" at a temperature near 40C, or do you think it's because the small particles are easily heated to a temperature high enough for the particles to react with air, even though they are not in the vapour phase?


Incidentally, your video shows the answer- look at the colour of the "flash".

Also, are you aware that you can get mists of high- flash-point oils to ignite at temperatures well below their flash points?
https://www.icheme.org/media/9045/xxiii-paper-43.pdf

By the way, why do you use the word "igneous"?

[Bored chemist]

Incidentally, if one of the mods can be bothered to split out the efforts to explain flash points to hamdani yusuf from the stuff about charcoal furnaces, that would improve the quality of the thread.

[eric2011 (OP)]

If for example, a homemade charcoal foundry like the attached photo, if another hairdryer is connected and turned on on the other side so is 2 hairdryers are blowing on the charcoal, what do you think the maximum ot top temperateure willl be reached inside? By guessing. 1300 C? 1600 c?