BURNING DIFFERENT WOODS

[Herman Meekes]

Stephen J Bungard wrote:

>Why do some woods burn better than others?
>
>What do I mean by better?  Well, obviously heat given out would be one
>criterion, but it seems to me that the problem with woods that burn less
>well is that they tend to smoulder or go out rather than burn completely.
>
>Speculating...  amount of lignin ..which must burn well with all those
>unsaturated bonds .. but all trees must have plenty of lignin in order to
>stand up...
>
>Amount of cellulose/hemicellulose - cannot be the problem per se as in sheer
>combustion terms, polysaccharides must burn pretty much the same.  However,
>different (amounts of) hemicelluloses might result in different physical
>structure eg porosity which could effect burning rate.
>
>Perhaps connected with porosity, amount of inorganics (dried sap, etc) ..
>high might dampen burning...
>
>Anybody know the answer?
>

Just my humble guess: porosity and possibly cell wall composition might
affect water retention, leading to decreased burning. Resins (as in fir or
pine) may increase burning rates.



Herman Meekes
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