>There has been a lot of controversy about the compressibility of wood. A
>minimum value can easily be obtained by using the range of specific
>gravities of modern woods (>10% moisture content)which vary from about .2
>for Balsa to over 1.0 (ironwood, for example) with an average of about .6.
>Given that carbohydrate is about 50% oxygen, and that coal has a specific
>gravity of 1.3 or so, the maximum compressibility of wood would be a factor
>of (1.3/.6*.5), or about 4. I don't know where the figures greater than
>this come from, unless one assumes the plant tissue from which coal is made
>is watermelon (in which case the factor would be about 20 or so).
I can tell you where some of it goes, I think. When plant matter is
compressed lots of carbon is turned into CO2 and CH4 and these gases escape
taking lots of carbon with them. Thus the problem is not merely what is the
percentage of carbon in coal or even what is the specific gravity of coal vs.
vegetable matter. Your equation above also forgets the hydrogen in
carbohydrates of the vegetable matter. It also forgets that only 18% of plant
matter is carbon while coal is 80% carbon.
glenn
Foundation,Fall and Flood
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