Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: CZARCAR on 30/08/2010 16:07:35

Title: ?what factors affect a wood pellet's thermal degradation?
Post by: CZARCAR on 30/08/2010 16:07:35

age of sawdust, age of pellet, etc........thanx

Title: ?what factors affect a wood pellet's thermal degradation?
Post by: CZARCAR on 22/10/2010 10:56:03

bump?

Title: ?what factors affect a wood pellet's thermal degradation?
Post by: CZARCAR on 30/10/2010 21:15:20

bump2

Title: ?what factors affect a wood pellet's thermal degradation?
Post by: RD on 30/10/2010 21:26:32

Maybe you are looking for factors which effect the "calorific value (http://en.wikipedia.org/wiki/Calorific_value#Heating_value)" of the pellets, (rather than "thermal degradation").

e.g. water content (http://en.wikipedia.org/wiki/Lower_heating_value).

Title: ?what factors affect a wood pellet's thermal degradation?
Post by: Bored chemist on 31/10/2010 09:47:29

Wood doesn't generally thermally degrade. What circumstances are you talking about?

Title: ?what factors affect a wood pellet's thermal degradation?
Post by: CZARCAR on 31/10/2010 16:21:54

sawdust is compressed,pelletized, & dried. wondering if age of sawdust, bark content,bacteria,+? might affect caloric value. also some pellets smell "pinier or fruitier" than others, might smell indicate a higher caloric value pellet?

Title: ?what factors affect a wood pellet's thermal degradation?
Post by: RD on 31/10/2010 17:02:16

Water content can make a big difference to the calorific value...

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http://en.wikipedia.org/wiki/Calorific_value#Heat_of_combustion_tables

When the fuel is damp some of the energy from the combustion is used to convert the water into steam,
that energy is not used to heat your boiler, (lost via water vapour up your chimney).

I suspect different types of wood will have different calorific values, but that water content will be the greatest factor.

Title: ?what factors affect a wood pellet's thermal degradation?
Post by: Geezer on 31/10/2010 22:42:21

I suspect the pitch content of the wood will contribute quite a bit of thermal energy, so the type of wood that was used to produce the pellets could make a big difference. It would be good if you could make the pellets yourself so that you really knew what was in them, but I don't think that's at all practical.