Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: David VandeBunte via facebook on 12/09/2010 16:30:02

Title: Does charred wood burn as well as unused wood?
Post by: David VandeBunte via facebook on 12/09/2010 16:30:02
David VandeBunte via facebook asked the Naked Scientists:
I thought of a question this last weekend while camping: does charred wood (after it looks like coal) burn as well as unused wood?

What do you think?
Title: Does charred wood burn as well as unused wood?
Post by: tommya300 on 13/09/2010 09:34:16
I do not think so. Once oxidized it is more difficult to ignite after cooled. The theory of back fires are used in some forest fire cases to create a barrier of to avoid the massive uncontrolled oxidation.

Charcoal briquettes are made from wood pulped by going thought a controlled process of charring, ground up to a powder and are press molded into these fancy sort of cubed shape, than dried.
Title: Does charred wood burn as well as unused wood?
Post by: imatfaal on 13/09/2010 14:39:42
I am not sure you're right there Tommy.  Many moons ago I remember being told that the black and white charred wood was the best wood to use to get the fire going in the morning - this is the sort of wood that looks almost scaly; often it is at the side of the fire and has partially burnt away.  I thought this stuff took no time at all to get burning and create the nucleus of your morning fire.  Will dig out a picture of the sort of wood I mean.
Title: Does charred wood burn as well as unused wood?
Post by: Geezer on 13/09/2010 20:21:48
Well, speaking as someone who knows bugger all not much about this subject, maybe charred wood burns "better".

At one time, charcoal was used extensively to produce iron from iron ore. It took quite a bit of work to make the charcoal from wood, so, presumably it was done for a good reason.
Title: Does charred wood burn as well as unused wood?
Post by: tommya300 on 14/09/2010 07:01:33
Guess I was looking at it all a different way.
Title: Does charred wood burn as well as unused wood?
Post by: peppercorn on 14/09/2010 15:14:10
"Does charred wood burn as well as unused wood?"

Depends what 'well' means...

Charred wood will burn hotter than unburned wood.
But, it will be more difficult to light than dry seasoned wood.
[Although, assuming it is charred and not yet solid charcoal it should be easier to ignite the non-charred core, by snapping in two and concentrating the heat (from kindling) on the unburnt (but very dry) wood centre.]

It will, obviously, have less energy available overall than in its non-charred state, but will be more energy dense by weight.

Charcoal seems to me to be a most undervalued commodity for increasing the wealth of rural communities in developing countries.   95% solid carbon would appear to be an amazingly usable and easily transportable -cheap- chemical feedstock.
Title: Does charred wood burn as well as unused wood?
Post by: billinthewoods on 04/12/2010 11:28:53
hi, im new to this site and have registered so i can answer this.

i produce charred wood as a superior fuel for wood burners and multi-fuel stoves.
i live in a yurt in a woods in the brecon beacons, wales. we have recently recorded temperatures of -18 degrees C and i can justifiably say that YES partly charred wood burns better than ANY "seasoned hardwood" i or my colleagues have encountered and some of them have been working in forestry, countryside management and coppice industries for over 40 years.
it burns hotter, burns for longer, lights easier, weighs less, costs less (for me, nothing), is quicker and easier to make and through coppicing is great for the environment.

PAR-CHARô has had readings of under 5% moisture content. most seasoned hardwoods are about 20%. it takes c.2 years to make good quality seasoned firewoods and c.36hrs to make almost perfect PAR-CHARô.
i light my burner every day and use it to cook off of, i light it with newspaper directly under the PAR-CHARô, sometimes i even just light the PAR-CHARô directly with a match.
i went away for a couple of days last week, when i got back the water in my dogs large bowl was frozen solid, the water in the kettle was forzen solid as were my bottles of drinking water. i have a 20ft diameter yurt and within 10 minutes it was too hot and i had to open the door.
anyone who sells "seasoned firewood" will tell you that a moisture reader poked into the end reads 20% and that that is good, as i say, PAR-CHARô has measured 5% moisture AFTER it has been drilled into and the CENTRE moisture content has been measured.
it also has a great effect on coppice industries, but that's another story. ill stop my rant now lol. i am extremely keen on this subject, for years Britain has been producing low grade charcoal and firewood, something that the Japanese have been producing in abundance for thousands of years, with modern technology we still cant crack it in the mainstream. we are one of the very few countries in Europe who employ old techniques and because of that we stray behind the rest of the world and in turn have to pay over the odds for low grade firewood and consequently overpriced burners and log stoves to accommodate the backward nature of the fuel they use. this whole "secondary and tertiary burning" that some stoves employ is useless and costs more money.
anyway, that really is my rant over. if you want to hear more then my email address is open to all.

hope this help