View Full Version : What is ash made of?


Cyperium
07-23-08, 06:30 AM
When anything organic burns, it becomes carbon and when the carbon has burnt it becomes ash, so what is ash made of?

Enmos
07-23-08, 06:35 AM
When anything organic burns, it becomes carbon and when the carbon has burnt it becomes ash, so what is ash made of?

Carbon compounds and all sorts of other stuff originally present in the material.

Cyperium
07-23-08, 06:44 AM
Carbon compounds and all sorts of other stuff originally present in the material.But ash is the leftovers from that which burns, so what other stuff doesn't burn? Is it possible to burn away all the ash?

Is ash present when burning other things than organical stuff?

I know that plastics just seems to turn liquid and to smoke.

Enmos
07-23-08, 07:01 AM
But ash is the leftovers from that which burns, so what other stuff doesn't burn? Is it possible to burn away all the ash?

Is ash present when burning other things than organical stuff?

I know that plastics just seems to turn liquid and to smoke.

"In the large majority of the real world uses of combustion, the oxygen (O2) oxidant is obtained from the ambient air and the resultant flue gas from the combustion will contain nitrogen:

CH4 + 2O2 + 7.52N2 → CO2 + 2H2O + 7.52N2 + heat

As can be seen, when air is the source of the oxygen, nitrogen is by far the largest part of the resultant flue gas.

In reality, combustion processes are never perfect or complete. In flue gases from combustion of carbon (as in coal combustion) or carbon compounds (as in combustion of hydrocarbons, wood etc.) both unburned carbon (as soot) and carbon compounds (CO and others) will be present. Also, when air is the oxidant, some nitrogen will be oxidized to various nitrogen oxides (NOx)."
http://en.wikipedia.org/wiki/Combustion

Everything that's too heavy to get airborne stays behind as ash. It's largely carbon compounds.
Mostly it's organics that will produce ash.

Read-Only
07-23-08, 11:49 AM
"In the large majority of the real world uses of combustion, the oxygen (O2) oxidant is obtained from the ambient air and the resultant flue gas from the combustion will contain nitrogen:

CH4 + 2O2 + 7.52N2 → CO2 + 2H2O + 7.52N2 + heat

As can be seen, when air is the source of the oxygen, nitrogen is by far the largest part of the resultant flue gas.

In reality, combustion processes are never perfect or complete. In flue gases from combustion of carbon (as in coal combustion) or carbon compounds (as in combustion of hydrocarbons, wood etc.) both unburned carbon (as soot) and carbon compounds (CO and others) will be present. Also, when air is the oxidant, some nitrogen will be oxidized to various nitrogen oxides (NOx)."
http://en.wikipedia.org/wiki/Combustion

Everything that's too heavy to get airborne stays behind as ash. It's largely carbon compounds.
Mostly it's organics that will produce ash.

It depends, of course, on what the original material was. A common one, wood, also leaves a fair amount of phosphorus and potassium compounds in the ash. ;)

OilIsMastery
07-23-08, 12:19 PM
When anything organic burns, it becomes carbon
"Organic" means carbon...:rolleyes:

Therefore anything "organic" that burns was carbon before it was burned.


what is ash made of?
Carbon and a bunch of other elements. Duh.

John99
07-23-08, 01:26 PM
Fly ash:

http://en.wikipedia.org/wiki/Fly_ash

This is cool also - Electrostatic Precipitator

http://en.wikipedia.org/wiki/Electrostatic_precipitator

Enmos
07-23-08, 01:26 PM
It depends, of course, on what the original material was. A common one, wood, also leaves a fair amount of phosphorus and potassium compounds in the ash. ;)

Of course (see post 2) ;)

Enmos
07-23-08, 01:28 PM
"Organic" means carbon...:rolleyes:

NO.

or·gan·ic
–adjective
1. noting or pertaining to a class of chemical compounds that formerly comprised only those existing in or derived from plants or animals, but that now includes all other compounds of carbon.
2. characteristic of, pertaining to, or derived from living organisms: organic remains found in rocks.
3. of or pertaining to an organ or the organs of an animal, plant, or fungus.
4. of, pertaining to, or affecting living tissue: organic pathology.
http://dictionary.reference.com/browse/organic

car·bon
–noun
1. Chemistry. a widely distributed element that forms organic compounds in combination with hydrogen, oxygen, etc., and that occurs in a pure state as diamond and graphite, and in an impure state as charcoal. Symbol: C; atomic weight: 12.011; atomic number: 6; specific gravity: (of diamond) 3.51 at 20°C; (of graphite) 2.26 at 20°C.
http://dictionary.reference.com/browse/carbon

Read-Only
07-23-08, 06:17 PM
Of course (see post 2) ;)

Yep, But I thought it might be of interest to the OP to know what some of the "other stuff" is. ;)

Enmos
07-23-08, 06:26 PM
Yep, But I thought it might be of interest to the OP to know what some of the "other stuff" is. ;)

Fair enough :p

OilIsMastery
07-24-08, 05:32 PM
NO.

or·gan·ic
–adjective
1. noting or pertaining to a class of chemical compounds that formerly comprised only those existing in or derived from plants or animals, but that now includes all other compounds of carbon.
2. characteristic of, pertaining to, or derived from living organisms: organic remains found in rocks.
3. of or pertaining to an organ or the organs of an animal, plant, or fungus.
4. of, pertaining to, or affecting living tissue: organic pathology.
http://dictionary.reference.com/browse/organic

car·bon
–noun
1. Chemistry. a widely distributed element that forms organic compounds in combination with hydrogen, oxygen, etc., and that occurs in a pure state as diamond and graphite, and in an impure state as charcoal. Symbol: C; atomic weight: 12.011; atomic number: 6; specific gravity: (of diamond) 3.51 at 20°C; (of graphite) 2.26 at 20°C.
http://dictionary.reference.com/browse/carbon
Seriously, borrow a clue.

http://www.merriam-webster.com/dictionary/organic


b (1): of, relating to, or containing carbon compounds (2): relating to, being, or dealt with by a branch of chemistry concerned with the carbon compounds of living beings and most other carbon compounds

Cyperium
07-25-08, 03:55 AM
Yep, But I thought it might be of interest to the OP to know what some of the "other stuff" is. ;)Yeah, thanks :)

I just stumbled upon the question when I thought about how fascinating it was that when things burn you can see what it is made of (carbon based) since it doesn't burn as easily :), then I just wondered what all the ash was.

So the other things are turned into gas (and smoke), but ash are the things that just simply won't burn.

If you heated it tremendously it would burn though (right?), how tremendously would you need to heat ash for it to burn? - depends on the things in it of course, but generally?

Sciencelovah
07-25-08, 04:37 AM
Yeah, thanks :)

I just stumbled upon the question when I thought about how fascinating it was that when things burn you can see what it is made of (carbon based) since it doesn't burn as easily :), then I just wondered what all the ash was.

So the other things are turned into gas (and smoke), but ash are the things that just simply won't burn.

If you heated it tremendously it would burn though (right?), how tremendously would you need to heat ash for it to burn? - depends on the things in it of course, but generally?


Ash is basically a residue resulted from an incomplete combustion. What are ash
made of is basically depends on:
1. the element that composed the material that you burn (of course).
2. the oxygen available for the combustion
3. the temperature you use for the combustion.

That is said, if the material composed of organic (including organic carbon)
and anorganic (including anorganic carbon), and you burn with insufficient
oxygen, you will likely get the organic carbon, anorganic carbon (carbon in
anorganic compound) and the rest of the anorganic (minerals) in the ash.
If you increase the oxygen until it is more than its stoichiometric requirement,
you can burn all the organic carbon as well. However, if the temperature is
low enough, you will still get the anorganic carbon and other anorganic /
minerals in the ash.

Here is an example of ash composition resulted from combustion of different
woods and different temperature (600 vs 1300 oC):

http://i216.photobucket.com/albums/cc247/x_inzomnia/ash_comp.jpg

Table source: Misra et. al, 1993, "WOOD ASH COMPOSITION AS A FUNCTION OF FURNACE TEMPERATURE" (pdf) (http://www.fpl.fs.fed.us/documnts/pdf1993/misra93a.pdf).

Sciencelovah
07-25-08, 04:42 AM
As an additional note, as Read-Only mentioned before:


It depends, of course, on what the original material was. A common one, wood, also leaves a fair amount of phosphorus and potassium compounds in the ash. ;)


Because ash mostly composed of mineral residue (that is the minerals which
compose the original material but left unburnt), such as phosphorous (P) and
potassium (K), such ashes are often used as fertilizer because it contains
nutrient needed for plant growth (N, P, K, etc). It is also common to use ash
for potash production, provided the ash contain potash (K) mineral.

Enmos
07-25-08, 06:32 AM
Seriously, borrow a clue.

http://www.merriam-webster.com/dictionary/organic

lol COMPOUNDS, not carbon. Carbon is an element, it's NOT organic.

I used to think you were just a trolling asshole, now I'm starting to think you are just an arrogant dumb shit.

OilIsMastery
07-25-08, 11:27 AM
Carbon is an element, it's NOT organic.
No shit...lol. I know.

Tell that to vitalists, organic chemists, and biogenic petroleum geologists.


I used to think you were just a trolling asshole, now I'm starting to think you are just an arrogant dumb shit.
Good scientific argument. I love ad hominem attacks because they make you look like a moron.

Enmos
07-25-08, 12:31 PM
No shit...lol. I know.

Tell that to vitalists, organic chemists, and biogenic petroleum geologists.
Then why did you say Carbon = organic ?


Good scientific argument. I love ad hominem attacks because they make you look like a moron.
Now you know why I call you one.

OilIsMastery
07-25-08, 01:18 PM
Then why did you say Carbon = organic ?
I don't say that; vitalists, organic chemists, and biogenic petroleum geologists say that.

Enmos
07-25-08, 02:37 PM
I don't say that; vitalists, organic chemists, and biogenic petroleum geologists say that.

Then what is this:

"Organic" means carbon...:rolleyes:

Therefore anything "organic" that burns was carbon before it was burned.


Carbon and a bunch of other elements. Duh.

Yorda
07-25-08, 04:22 PM
i thought ash was made of ash, but i guess i was wrong. thanks for the information.

OilIsMastery
07-25-08, 09:30 PM
Then what is this:
That is according to vitalists, "organic" chemists, and biogenic petroleum geologists. Ask them why they believe that don't ask me. Carbon is abiotic.

nietzschefan
07-25-08, 11:03 PM
As an additional note, as Read-Only mentioned before:




Because ash mostly composed of mineral residue (that is the minerals which
compose the original material but left unburnt), such as phosphorous (P) and
potassium (K), such ashes are often used as fertilizer because it contains
nutrient needed for plant growth (N, P, K, etc). It is also common to use ash
for potash production, provided the ash contain potash (K) mineral.

Which is why some forest fires are quite natural and sometimes should be left to burn.

Enmos
07-26-08, 01:42 AM
That is according to vitalists, "organic" chemists, and biogenic petroleum geologists. Ask them why they believe that don't ask me. Carbon is abiotic.

Well ok.. I don't know about vitalists and I don't know what exactly you mean by "organic" chemists but I very much doubt that biogenic petroleum geologists think that carbon is alive. It's retarded.

Reiku
07-26-08, 02:48 AM
When anything organic burns, it becomes carbon and when the carbon has burnt it becomes ash, so what is ash made of?

Oh, ok.

Vkothii
07-26-08, 06:51 AM
Apparently a certain dipstick can't figure out the difference between carbon chemistry and organic chemistry.
Organic Chemistry is a subject, so is Biochemistry, they intersect, but they're in different parts of the campus usually. Both involve carbon chemistry. Carbon chemistry involves carbon (I think).

Now, what the hell is: "a campus"?
Anyone?

OilIsMastery
07-26-08, 07:13 AM
Well ok.. I don't know about vitalists and I don't know what exactly you mean by "organic" chemists but I very much doubt that biogenic petroleum geologists think that carbon is alive. It's retarded.
I suggest you do some reading and come back to us when you have some knowledge and wisdom at your disposal.

OilIsMastery
07-26-08, 07:15 AM
Apparently a certain dipstick can't figure out the difference between carbon chemistry and organic chemistry.
Please enlighten us oh omniscient one.


Organic Chemistry is a subject, so is Biochemistry
Congratulations. Now you can apply to college.

Vkothii
07-26-08, 07:18 AM
Please enlighten us oh omniscient one.

You really are a dipstick, right?
Carbon chemistry is the chemistry that the schools of Physics, Mineralogy, Biochemistry, Biology, and Organic Chemistry have got covered.

So, you know what a college is, huh?

OilIsMastery
07-26-08, 07:23 AM
Organic Chemistry
You don't know what organic chemistry is.

http://www.merriam-webster.com/dictionary/organic


b (1): of, relating to, or containing carbon compounds (2): relating to, being, or dealt with by a branch of chemistry concerned with the carbon compounds of living beings and most other carbon compounds
Organic means carbon because vitalists are retarded.

Enmos
07-26-08, 07:29 AM
I suggest you do some reading and come back to us when you have some knowledge and wisdom at your disposal.

Coming from you.. :bugeye:

Enmos
07-26-08, 07:31 AM
You don't know what organic chemistry is.

http://www.merriam-webster.com/dictionary/organic


Organic means carbon because vitalists are retarded.

Now look up "biotic".
From the dictionary you used:
http://www.merriam-webster.com/dictionary/biotic

Enmos
07-26-08, 07:33 AM
Organic means carbon because vitalists are retarded.

You need to polish your writing skills :rolleyes:
Where does it say in the definition that organic means carbon. Explain it to me, I'm dumb.

OilIsMastery
07-26-08, 07:39 AM
Where does it say in the definition that organic means carbon. Explain it to me, I'm dumb.
Reading comprehension problems?

http://www.merriam-webster.com/dictionary/organic


b (1): of, relating to, or containing carbon compounds

Enmos
07-26-08, 07:42 AM
Reading comprehension problems?

http://www.merriam-webster.com/dictionary/organic

What don't you understand ? I will explain.
Heh.. never mind you are too stupid anyway.

OilIsMastery
07-26-08, 07:45 AM
What don't you understand ? I will explain.
Heh.. never mind you are too stupid anyway.
You should read and quote the definition you deliberately ignored.

Vkothii
07-26-08, 07:49 AM
So there's a dipstick (who looks much like another dipstick who fails to understand the difference between carbon chemistry and organic chemistry) who doesn't think organic chemistry or biochemistry is carbon chemistry.

Now we got a spare dipstick.

OilIsMastery
07-26-08, 07:51 AM
So there's a dipstick (who looks much like a dipstick who fails to understand the difference between carbon chemistry and organic chemistry)
Still waiting to hear what the difference is. Please go learn what organic chemistry is so you can sound intelligent.

Vkothii
07-26-08, 07:54 AM
Is there another one??

Now there's a dipstick who looks like they think organic and carbon aren't any different, they want to hear something that explains the difference?

Enmos
07-26-08, 08:01 AM
You should read and quote the definition you deliberately ignored.

I read it alright.
It says that something organic is made of carbon compounds, relates to carbon compounds, or contains carbon compounds.
It does not say the organic means carbon.

Enmos
07-26-08, 08:02 AM
Is there another one??

Now there's a dipstick who looks like they think organic and carbon aren't any different, they want to hear something that explains the difference?

They ?

OilIsMastery
07-26-08, 08:09 AM
a branch of chemistry concerned with the carbon compounds of living beings and most other carbon compounds
Do you know what nonliving carbon compounds are? Organic chemistry studies nonliving carbon compounds.

Enmos
07-26-08, 08:12 AM
It does not say that.


Do you know what nonliving carbon compounds are?


Wrong. Organic means carbon according to vitalism.

You gave the definition, live with it.

OilIsMastery
07-26-08, 08:13 AM
S0-called "organic" chemistry studies nonliving carbon compounds. Deal with it.

Enmos
07-26-08, 08:14 AM
S0-called "organic" chemistry studies nonliving carbon compounds. Deal with it.

Yea and ?

OilIsMastery
07-26-08, 08:17 AM
Yea and ?
:roflmao:

:bravo:

Enmos
07-26-08, 08:18 AM
:roflmao:

:bravo:

Have I ever said otherwise ?

OilIsMastery
07-26-08, 08:21 AM
Have I ever said otherwise ?
:roflmao:


Carbon is an element, it's NOT organic.

Enmos
07-26-08, 08:26 AM
:roflmao:

Oh so it is organic according to you ?

How does carbon equate to carbon compounds in your mind ? Just curious.. ?

Enmos
07-26-08, 08:26 AM
Are you saying that carbon is alive ? :crazy:

OilIsMastery
07-26-08, 08:28 AM
Oh so it is organic according to you?
I refer you to my comments posted above.


How does carbon equate to carbon compounds in your mind ? Just curious.. ?
Carbon compounds are made up of carbon.

Enmos
07-26-08, 08:28 AM
Carbon compounds are made up of carbon.

Among other elements. So why do you say that carbon = carbon compounds again ?

OilIsMastery
07-26-08, 08:29 AM
Are you saying that carbon is alive ? :crazy:
I refer you to my comments posted above.

Vkothii
07-26-08, 04:27 PM
They ?The universal pronoun: applied in those cases where one is unsure of the number (or superposition) of individuals. Multiple personality types, that sort of thing.

Enmos
07-26-08, 05:36 PM
The universal pronoun: applied in those cases where one is unsure of the number (or superposition) of individuals. Multiple personality types, that sort of thing.

Ah ok, I thought you might have misread one of my posts :p

OilIsMastery
08-05-08, 12:09 PM
"The subject of organic chemistry was wrongly taken by petroleum geologists long ago to mean chemistry of biologic origins. You can still have a book of organic chemistry that has nothing to do with organisms at all." -- Thomas Gold, 2002

Myles
08-05-08, 12:14 PM
Ash is made from bodies in crematoria, Next ?

OilIsMastery
08-05-08, 12:19 PM
Ash is made from bodies in crematoria, Next ?
Isn't that funny? That's exactly why people think we are "carbon based" even though we are actually hydrogen and oxygen (H2O) based.

Myles
08-05-08, 03:43 PM
Ashes to ashes. dust to dust.

Vkothii
08-05-08, 06:41 PM
Funk to funky.

We know (etc)

OilIsMastery
08-06-08, 11:30 AM
Back to the OP, according to volcanologist John Westgate from the University of Toronto, all ash has a unique chemical signature.


Westgate is a quaternary tephrochronologist, in plain English, a volcano detective. Westgate can identify a volcano anywhere in the world, using just one critical piece of evidence, volcanic ash.

Give Westgate some volcanic ash, and he'll track down the volcano that produced it.

JOHN WESTGATE (University of Toronto): We try to find out where the ash comes from, its parent volcano. And in that framework it's exactly like a DNA signature.

NARRATOR: Volcanic ash from every eruption is unique. It has a specific mixture of rock fragments and minerals that can point to its source.
Link (http://www.pbs.org/wgbh/nova/transcripts/3312_megavolc.html)

Stryder
08-06-08, 12:40 PM
Isn't that funny? That's exactly why people think we are "carbon based" even though we are actually hydrogen and oxygen (H2O) based.

Actually I think you find it's because we are "Carbon Based". If you were to look at CH4 (not saying we are comprised wholey of that) the Hydrogen only has one bond so technically it's the Carbon that's the main element even though it's "outnumbered". Technically I doubt anything would ever be classed as "Hydrogen Base" other than of course "Hydrogen".

This is also the reason we can not be H2O based, because you are attempting to base our foundations round an already formulated molecule. (The Molecule can't be Base in this instance)

Billy T
08-06-08, 06:51 PM
Quick skim indicates no one has yet mentioned that wood or coal fires in homes fireplaces leave unseen residues in the chimney also. They condense out of the hot flue gases and occasionally catch fire. (Can make deep roaring sound when they do as the chimney helps it "organ pipe".) Sometimes, especially with cracked chimney, this burns down houses. Most would not think of these deposits as ash, unless ash is defined as the material left behind by wood or coal fires.

Fernan
04-12-10, 06:06 PM
You guys look like 8 yr. old kids arguing about meaningless stuff.


But ash is the leftovers from that which burns, so what other stuff doesn't burn? Is it possible to burn away all the ash?


Yes, it is possible.

Every element has a boiling point beyond which it will evaporate for Carbon it is 4827 degrees C. The element with the highest boiling point is Tungsten at 5660 degrees C.

If you define "to burn" as "to undergo combustion" (i see that you need to choose your words very carefully in this forum) then you will need a compound with enough fuel and enough Oxygen to produce the right amount of heat for long enough to evaporate everything that won't combust.

If you use a broader definition of "to burn" then all you need to do is heat the compound and/or reduce it's pressure enough for it to evaporate. As mentioned above anthing will evaporate beyond 5660 degrees C at atmosphere pressure.

It's also worth mentioning that Carbon's melting point is the 3500 degrees C and it's the highest melting point of all known elements, so if you heat ashes beyond this point (as long as they're high in Carbon) it will turn into a crystal clear liquid, all the impurities will sink to the bottom and if you let it cool under enough pressure you get a diamond.


Is ash present when burning other things than organical stuff?

Yes, whenever you combust a compound containing some fuel and other elements ( not necessarily Carbon ), and the fuel does not produce enough heat to evaporate everything else you'll get some leftovers that are by your definition ashes.

The reason why ash is associated with organic compounds is because as mentioned above, Carbon has the heighest melting point so whenever you burn something organic almost everything else is going to either melt or evaporate.

Captain Kremmen
05-04-10, 05:45 AM
It is mainly made from metal oxides, which have a high boiling point, and would not be driven off in fires of normal heat.


Calcium Oxide white, has a boiling point of 2850C
Sodium Oxide, white, has a boiling point of 1950C
Magnesium Oxide, white, has a boiling point of 3600C

Potassium Oxide, yellowish white, decomposes at >350 so is probably burned off.
So will the oxides of nitrogen, sulphur, and phosphorous.

There are other metals in small quantities as well.

People used to make ash into soap by boiling it up in water with fat.

Captain Kremmen
05-05-10, 07:53 AM
Ash from a cremation oven, 760° to 1150°C (1400° to 2100°F), during the cremation process, will have few contaminants, and should be whiter.
Get down your granny's urn from the sideboard and check would you?

Sorry Gran, I'm just checking you for carbon remains. Won't be a jiff.

Facial
05-18-10, 02:12 PM
It is mainly made from metal oxides, which have a high boiling point, and would not be driven off in fires of normal heat.


Calcium Oxide white, has a boiling point of 2850C
Sodium Oxide, white, has a boiling point of 1950C
Magnesium Oxide, white, has a boiling point of 3600C

Potassium Oxide, yellowish white, decomposes at >350 so is probably burned off.
So will the oxides of nitrogen, sulphur, and phosphorous.

There are other metals in small quantities as well.

People used to make ash into soap by boiling it up in water with fat.

Finally, back on topic.

Nitrogen oxides are always in gaseous form, so they probably aren't a part of ash. The three main nutrients for plants, abbreviated "NPK" - nitrogen, phosphorus, and potassium - happen to be their main constituents after the three main elements of life - H,O,C.

Potassium oxide is formed in potash, but quickly forms into potassium hydroxide once the heat is reduced.
Phosphorus oxide is present too, but also absorbs water and turns into something else.
Magnesium oxide, derived from chlorophyll, would be fairly stable, turning into MgOH over a longer period of time.

Cyperium
08-25-10, 03:33 PM
Thank you for all your replies, this is a old thread and is yet at the first page after all this time! Never expected it to grow this large :D, shows that it was a good question though!

ericdaniels
05-21-12, 11:01 PM
i think those 2 nerdy guys should have a fight or keep arguing. it was kinda entertaining.

Gremmie
05-21-12, 11:22 PM
i think those 2 nerdy guys should have a fight or keep arguing. it was kinda entertaining.

They were just making ashes of themselves...

Of course that was a long time ago.:bugeye:

WangLP
08-01-12, 09:56 PM
I also want to know the answer...

texsoroban
02-05-14, 05:07 PM
Don't read any further in this thread. Wood ash typically amounts to 1-2% of the original woods mass prior to burning. assuming that all of the cellulose lost all of it's water of hydration (CH + O -> C + h2O) and got converted to charcoal (carbon) and then all of the carbon got enough air and heat to combust ( C+O2 -> CO2) then all you will be left with are non-combustable salts of Calcium, Sodium, Potassium, and Magnesium with trace amounts of others. completing the salts are chloride, carbonate, sulfate sulfite, nitrate, Oxide and phosphate. The mix will vary depending on what you are burning, how hot it was, and how much air was able to get to it. some of the salts are soluble in water, some are not.

Billy T
02-06-14, 04:55 AM
Welcome to Sciforums.
Don't read any further in this thread. Wood ash typically amounts to 1-2% of the original woods mass prior to burning. assuming that all of the cellulose lost all of it's water of hydration (CH + O -> C + h2O) and got converted to charcoal (carbon) and then all of the carbon got enough air and heat to combust ( C+O2 -> CO2) then all you will be left with are non-combustable salts of Calcium, Sodium, Potassium, and Magnesium with trace amounts of others. completing the salts are chloride, carbonate, sulfate sulfite, nitrate, Oxide and phosphate. The mix will vary depending on what you are burning, how hot it was, and how much air was able to get to it. some of the salts are soluble in water, some are not.Nice answer, but you will be left with oxides of these salts, at least while still very hot, and some will be quite soluble, others not. See post 67 for some more facts.

BTW, if the wood is burnt in chamber "starved" for O2, there will lot of carbon left as coke or charcoal provided you let it cool before extracting it.* In Brazil this chamber is often made from sun-dried mud bricks, with walls many "bricks" thick and each layer of slightly smaller radius - a dome shaped chamber. The inner layer is sold as are not bad bricks, and the next time a new chamber is built, new sun dried bricks form the outer layers. Usually this is done near the edge of a road in rural areas as the smoldering makes lots of smog.

* You can tell when the charcoal and bricks are (or soon will be) ready for sale if you drive that road daily - no smoke rising and dome may be half gone. I don't know, and it depends on the weather some, but think the production cycle takes about a month, so usually there are at least two, "out of phase" ovens. There is always a large array of bricks drying in the sun, and full time work, often for the children of the area making these bricks. - It is a way of life, not entirely legal as cutting trees is illegal. They are usually cut some miles from where the field of drying bricks is during the night.

I had a cattle farm for a decade and at least twice some of my trees were stolen. The cutters were kind - did not clear cut, but were selective in their cutting. Every month or so, a government plane flies over your farm taking photos. A neighbor did slightly and slowly expand his pasture into the adjoining woods, of his land. They finally caught him - I think he did both jail time and paid a big fine. Brazil has probably the world's tightests environmental laws and enforcements in the world.

There are a few trees in pastures - left for cows /steer to have shade to rest in. One in my pasture had toxic leaves that a strong wind blew off. Several of my steers got sick and one died. I only visited the farm for a couple of week-ends each month as had very honest smart field man.** He "came with the land" when I bought it - had worked there since a child and almost knew every blade of grass by name. When I arrived, and learned what had happen, I said: "Cut that damn tree down and burn it." He explained: You don't want to do that, but knew what to do and had already done it. Cut a deep grove thru the bark all around the trunk. The government's photographing plane would see tree dying and after standing dead for few years we could safely cut it down.

** A leader of the local community and very intelligent and honest - a politician once gave him a new steel door, just for every day wearing the a political T-shirt the month before election. He was naturally gifted in personal relationships - I think most of the valley voted as that T-shirt said to. He was also nearly illiterate, so Brazil lost potentially one of the best diplomats it could have had. He never knew what day I would come, but was always up in the field with his hoe when I arrived. The cattle make Darwinian selection favoring the weeds when eating the good grass - he did the opposite - selectively killed weeds to keep the pasture in good shape.

I paid him the local equivalent of $100/ month for his 44 hour work week (Half day on Saturday). That got other "absentee" owners mad at me. Their workers wanted better pay too. The whole valley lived self-sufficient out side the cash economy. Grew their own coffee, tobacco, food, made cooking *** lard from the pigs, had lots of chickens, a productive garden, clean unpolluted water, fresh milk every day, etc. No one had a refrigerator, so if they killed an old cow not giving much milk any more, all came to share the "beef feast." No one ever ate even just a samwich in the presence of another without offering to share. My hired man, offered to me part of his lunch (beans & rice) during his lunch breaks if I went outside my small house there, so I rarely did. A few times, just to be polite, I accepted his offer, returned to get a small bowl, and ate some with him. I usually then gave him a can of Vienna sausages or sardines I had for him to later share with his wife (after confirming he did have a rarely used can opener).

*** Their wood fire stove is clever design, with only three or four holes (covered by lids or with pots) in one small piece of flat steel. It has an "entrance table" and burns logs from the end - no need to cut the dry fallen limbs used as fuel. Just jump on them supported at ends by two rocks until the pieces are not more than about 6 or 7 feet long. The cook feeds them into the combustion part of the stove as needed to regulate the heat.

They will all be still doing well, when the "advanced world" collapses under its growing, unpayable debt, with no food in your local grocery store etc.

Mathers2013
02-06-14, 10:57 AM
You already gave my answer: carbon.

Billy T
02-06-14, 11:33 AM
You already gave my answer: carbon.Except that is not true. Almost, if not fully, by definition, "ash" must be material that will not oxidize more.

CaptainWho
06-08-14, 01:03 PM
Then why did you say Carbon = organic ?


Now you know why I call you one.

"All living things on our planet are constructed of organic molecules-complex microscopic architectures in which the carbon atom plays a central role."
-Carl Sagan

Enmos
06-08-14, 06:25 PM
"All living things on our planet are constructed of organic molecules-complex microscopic architectures in which the carbon atom plays a central role."
-Carl Sagan

"...plays a central role."

Carbon in itself is an element. It's not organic.