RogueRose
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Extracting useful compounds from creosote - phenols, guaiacol, xylenol, etc
Well it's that time of year where people may be cleaning out stoves and chimney's of built up creosote and some chimeny's can hold A LOT of it (ours
had over 7 5 gallon buckets of it after 6-8 years of use) - some jobs fill a 55 gallon drum of the stuff.
Now there are a number of different creosotes, wood, coal, oil, gas based which is all dependent upon what is being burnt in the system and then the
content of the creosote varies even more based upon what type of fuel is being burnt, especially the types of wood.
It seems that the two highest components are various phenols and guaiacol. I wasn't aware that the creosote itself was flammable (in fact it is
highly flammable once heated) and is one of the main reasons for chimney fires. This stuff is usually just thrown out in normal waste disposal
avenues (land filling or burning at municipal levels). If anyone wants to experiment with this it can easily be obtained (should be free of charge)
from any company that sweeps chimneys or ask a property owner if you can access the chimney clean out port at the bottom of the chimney or scrape some
off the doors of the stove (if it is wood stove especially).
I searched through the forum and didn't find any threads about processing creosote but found some references where it was discussed in some part about
a possible source of phenol.
So, I'm wondering if anyone has experience with this or has ever looked at its potential. I'm guessing that seperating the compounds might be
possible by fractional distillation but I really don't know how this stuff will work when heated as to whether it melts or if it needs some kind of
solvent or something that will allow it to melt and mix together better before distillation.
I guess the biggest question is whether there are any worthwhile products that can be extracted from it and as said, content varies greatly depending
upon what is being burnt.
Can anyone shed any light on this topic and whether distillation would be the best method to separate the compounds?
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aga
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Start by mixing well with water.
Anything non-soluble will separate, so you can simply decant it off.
Saves many hours of distilling to get to first base.
After that, many hours of distilling each portion.
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NEMO-Chemistry
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Charcoal making in a steel drum gives alot of what you creosote. Maybe soot would leach something useful.
Real creosote was banned for general sale in the UK, it was carcinogenic, so i would take precautions.
[Edited on 17-11-2017 by NEMO-Chemistry]
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RogueRose
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Thanks for the suggestions. I was under the impression that creosote wasn't water soluble but i've never worked with it other than to scrap from
stove door or chimney clean out.
I did read that it is most likely carcenogenic and was a little concerned when I found how it is disposed in normal practice for cleaning residential
house chimney's. When a house has an average of 25-55 gallons per cleanout (so maybe 5-10 gallons per year) that is significant amounts of
carcinogens being disposed of in a non-hazardous/clean manner. I wonder if local municipalities even consider this or if it is worth mentioning to
local governances where coal and wood is still used in a lot of houses (where I live maybe 20% or more - but vast majority is wood based).
I'm not very experienced with fractional distillation, but would that be the best method for distilling creosote and if so, what kind of fractioning
column (if there are different types) or minimum length for this application.
With the recent postings about different methods to obtain phenol (or derivatives) and it looks like oak creosote distilled between 200-210C yields
about 55% phenol!
From what the Wiki page says that the m-phenol extracted from the oak, with simple methylation (addition of methanol) yeilds Anisole, or
methoxybenzene. IDK if this could be useful for anything but looks like it could be interesting for a base of perfume scents.
Guaiacol is also fairly expensive and I know it is used as a precursor of Eugenol and Vanillin
Here are some composition numbers as per wiki
Composition of a typical beech-tar creosote
Phenol - C6H5OH - 5.2%
o-cresol - (CH3)C6H4(OH) - 10.4%
m- and p-cresols - (CH3)C6H4(OH) - 11.6%
o-ethylphenol - C6H4(C2H5)OH - 3.6%
Guaiacol - C6H4(OH)(OCH3) - 25.0%
1,3,4-xylenol - C6H3(CH3)2OH - 2.0%
1,3,5-xylenol - C6H3(CH3)2OH -1.0%
Various phenols - C6H5OH - 6.2%
Creosol and homologs C6H3(CH3)(OH)(OCH3)— 35.0%
Constituency of distillations of creosote from different woods at different temperatures
Beech wood from 200-220C
Monophenols - 39.0 %
Guaiacol - 19.7 %
Creosol and homologs - 40.0%
Loss - 1.3%
Beech wood from 200-210C
Monophenols - 39.0 %
Guaiacol -26.5 %
Creosol and homologs - 32.1%
Loss - 2.4%
Oak wood from 200-210C
Monophenols - 55.0 %
Guaiacol - 14.0 %
Creosol and homologs - 31.0%
Loss …..
Pine wood from 200-210C
Monophenols - 40.0%
Guaiacol - 20.3%
Creosol and homologs - 37.5%
Loss - 2.2%
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NEMO-Chemistry
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I thought about chimney soot... Dont do this, i can see some real potential horrors. We got two open fire places, this is why i mentioned soot. But
reading what you put reminded me of something, we had the chimney sweep in maybe 2 years ago now.
Since that time we have burnt all sorts on the fire, you tend to just chuck stuff on when the fire is alight, so plastic wrapping etc etc etc has all
gone on it. Makes you wonder what soot will actually contain, i think if your going to potentially concentrate it and separate it, then maybe its a
bad idea.
I dont think creosote as such is soluble in water, but i know when making charcoal, you get alot of what i would call oily gunk, and you would call
creosote. Might be a safer way, also consider hard wood and softwood give different types of oily gunk after you make it.
Watch a few videos on u tube about making charcoal, you get a good idea of the shit that comes out. Adding water or steam as it cooks pushes alot of
the oily shit out.
Oily woods like pine and teak might yield something interesting.
[Edited on 18-11-2017 by NEMO-Chemistry]
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RogueRose
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Quote: Originally posted by NEMO-Chemistry  | I thought about chimney soot... Dont do this, i can see some real potential horrors. We got two open fire places, this is why i mentioned soot. But
reading what you put reminded me of something, we had the chimney sweep in maybe 2 years ago now.
Since that time we have burnt all sorts on the fire, you tend to just chuck stuff on when the fire is alight, so plastic wrapping etc etc etc has all
gone on it. Makes you wonder what soot will actually contain, i think if your going to potentially concentrate it and separate it, then maybe its a
bad idea.
I dont think creosote as such is soluble in water, but i know when making charcoal, you get alot of what i would call oily gunk, and you would call
creosote. Might be a safer way, also consider hard wood and softwood give different types of oily gunk after you make it.
Watch a few videos on u tube about making charcoal, you get a good idea of the shit that comes out. Adding water or steam as it cooks pushes alot of
the oily shit out.
Oily woods like pine and teak might yield something interesting.
[Edited on 18-11-2017 by NEMO-Chemistry] |
Well there is NO plastics in our fire, I garuntee that unless we had some intruders come in and put something like that in the fire. We don't even
burn colored paper, glossy paper, printer paper or anything of the sort. The only thing in our wood stove is a little newspaper to start the fire
after cleaning out ash every 4-6 weeks and then natural hardwoods from our property (oak or cherry). There maybe 2lbs of newspaper per year the rest
is wood that we split, so it should be pretty straight and clear/clean creosote. Now the "soot", I'm not sure what you mean about that, I thought
that is basically like lamp black, just carbon.
our chimney always looks totally clean with a few flakes here and there of creosote that flake off and drop to the clean-out pit. The fire burns
ultra clean and the chimney has never needed cleaned in 35+ years (though we do put the brush down just to make sure). It helps when the wood is
really dry as wet wood releases more tar and creosote I beleive.
AS far as charcoal making, yeah, I've tried that and it is a bloody mess. Tried filling a 5 gal bucket (heated over a wood/charcoal forge) with
blocks of oak from a furniture shop (scrap cuttings) and it ended up dripping out the rim of the lid and all over the concrete in a permeate stain
that was high in tar (probably could be cleaned with acetone, alcohol or similar). The charcoal inside had a sticky layer on the outside that was
gross, but it burnt nicely in the forge as a fire starter - never got it to be charcoal as I stopped b/c it was too messy.
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Vosoryx
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I think this is a very interesting idea, and I doubt there would be any more dangers than what is a constant in, for example, fractionally distilling
flammables.
I doubt that any product you get would be pure enough to warrant the process, and I encourage you to enjoy the task of glassware clean-up. All the
same, however, it might be a fun proof of concept.
I hope that, if you do decide to try this, you keep us informed.
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wg48
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After I brushed my chimney I had a few gallons of soot. I used some of it in an attempt to colour some cement. When mixed with water and left to
settle it produces dark brown clear solution. It did not smell of creosote just chimney soot though mostly wood had been burnt in an open fireplace.
Curiously it inhibited the setting of cement for at least three days. I was forced to replace the cement with regular cement. I did wonder how much
bucky balls it contained and how that could be separated from the gunk.
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RogueRose
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Well I'm not exactly sure what soot would look like in a chimney but i've seen fire places that have blackened around the edges and on the inside
masonry/stone. It seems kind of powdery but with a sticky nature, not like the smooth dry feeling of lamp black. The creosote I have is bery shiny
and glossy, crispy, thin flakes (some 3"x 6" in size but probably .5-1mm thick, most are much smaller pieces though). The creosote crunches kind of
like potato chips and crumbles.
Our stove is made of plate steel and a steel double walled chimney that is very tall so it has excellent draft and there is usually no smoke coming
out - so it is a very clean burn. IDK if this makes for less soot (I know less creosote) and I didn't seem to notice much of any on clean out. Maybe
it is mixed in with the finer pieces of creosote in the bottom or it is layered in the creosote. I figured that the soot would be a component of the
creosote but I guess not.?
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unionised
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Extracting the creosote with sodium hydroxide solution would dissolve the phenols / acids and leave a lot of (relatively uninteresting) hydrocarbons
behind.
Passing CO2 into that solution would free up the phenols (which would separate out as an insoluble layer, while leaving any carboxylic acids in
aqueous solution as their salts.
Redistilling that phenolic fraction should give you phenol, cresols, xylenols naphthols etc.
The non-phenol fraction is probably rather full of nasty poly-cyclic aromatics that you don't want to mess with.
It might be interesting to do an acid wash of it, neutralise the washings and see if you get any pyridines etc.
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NEMO-Chemistry
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We have very high chimneys, its a very old large house, tall ceilings. I found the soot changes as you go up the flu, kind of like a soot fractional
column.
Most the stuff near the bottom does seem to be Carbon, but two things made me think about it, one of them is old time allotment growers who want it
big time. Apparently great soil conditioner?? The other was, soot taken from near the bottom the bottom of the chimney smells alot different from the
top.
Wood if not completely seasoned, contains alot of chemicals, these should deposit in some form in the smoke as it rises.
March/April is likely next time it will be cleaned, then the chimneys get capped to stop birds nesting in them. I might go up on the roof when dry and
grab some from near the top. Sodium Hydroxide sounds like a good idea, from the brick work at the back of the fireplace, i would think its fairly
acidic.
If you havnt burnt plastics then fair enough, we burn burn coal and wood, most waste stuff that burns often gets put on. I think next year we are
getting wood burning stoves put in, open fireplaces are crap from a heat point of view.
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aga
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In amateur practice, Fractional Distillation is simply switching the receiver each time the temperature stabilises at a particular level. The contents
of each pot is a different 'fraction'.
Booze distillers do 'fractional distillation' by throwing away the first drops that come over below 78 C (the 'heads') as that 'fraction' contains
things like Methanol.
Then they collect the main flow of ethanol at 78~79 C (depending on the distiller) and stop when the temperature climbs above that.
The main flow 'fraction' is mostly the ethanol & water azeotrope.
Stuff that comes over above 79 C (the 'tails' in booze distilling) contains things like Furfural, which tastes bitter, making it a nasty fraction !
Having a column, e.g. vigreux, definitely helps to get much cleaner fractions.
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aga
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Oh, Definitely inferior to a purpose-made wood burner when it comes to heating.
It's that time of year again, so here's mine in action.
Oddly the thing has no grate ...
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UC235
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I think you've fundamentally confused two things based off of name. The wood-tar creosote rich in phenolics is an oily liquid produced by destructive
distillation of wood with limited oxygen. The creosote in chimneys is a mess of carbon and polycyclic aromatics. While it might contain some small
proportion of extractable phenolics, I think you're wasting your time.
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