Re: GAS-L: The Mystery of heat variance in biomass

["Dick Glick" <dglickd@pipeline.com>]

Hello Carefreeland and All --

Plant initial chemistry -- photosynthesis -- is the light catalyzed reaction
of carbon dioxide and water to form carbohydrates.   As is true for both
animals as well as for plants -- respiration accounts for further reactions.
Photosynthesis provides the mechanism for formation of carbohydrates and
then respiration in plants is the reaction of carbohydrates with oxygen to
yield carbon dioxide and oxygen depleted organic plant substances.  Examples
of interest is the plant progeny mechanism -- the seed producing process --
as well as the formation of lignin, plant oils, etc.

Best, Dick


----- Original Message -----
From: <Carefreeland@aol.com>
To: <dglickd@pipeline.com>; <stoves@crest.org>; <gasification@crest.org>;
<wastewatts@yahoogroups.com>
Sent: Wednesday, January 02, 2002 11:56 AM
Subject: Re: GAS-L: The Mystery of heat variance in biomass


> Dear dglickd,
>     This is exactly what we need every now and then, a good organic
chemist.
>  This formula is a great way to determine by analysis, what a plant is
> producing for the purpose of converting chemistry to physics.
>     What I am deriving from this formula is the way in which some plants
> produce higher caloric value per mass.  If one is to take a chart of local
> firewood's we can see a very direct correlation between strength/weight of
> fiber and heat value.  This could easily be explained by the presents of
more
> high energy lignin, which is a bonding agent in the fibers. Lignin has
less
> percentage oxygen than cellulose.
>     Osage orange (hedge) comes out near the top by my chart, at 7073 Btu
per
> pound. It is indeed one of the strongest woods known to man hence it's
name
> Boise, DE Ark or "wood of the bow."  This is from figures from Firewood
for
> your Fireplace by Warren Donnelly, 1974.  Probably air dry wood.
>     How do we explain the high figure for Black cherry at 7142 Btu/pound,
or
> Cottonwood at 7142?  I would say that the raw sugars present in cherry sap
> must be very high energy.  Any clue as to what their formula is?
Cottonwood
> may be low strength because of the light density of fibers lacking a good
> "weave."  Cottonwood also has so many large pores that it tends to rot
fast.
> The high heat here may also come somewhat from low ash content.
>     Pine is much lower at 6190 Btu/pound, but again are we talking split
> heartwood or small stock with a high bark to weight ratio?  I would
venture
> to say that the resin here, which is more hydrocarbon in nature, would be
> very high in heat, but present less in the core than in the bark.  Again,
> what variety of pine, and growing where?
>     Silver maple comes out lower at 5937 Btu/pound, probably due to
simpler
> cellulose and ash.  Box elder is very low at 4783 Btu/pound but it is very
> high in ash.
>     I will say that all of this indicates that the usual ways that trees
> repair damage and add strength for wind resistance all seem to add heat
> density to the wood.  I cannot make this a rule though.
>      Cork bark elm is no higher heat than Siberian elm, yet it makes
stronger
> wood.  Why? The woven grain of the cork bark gives it it's strength.  The
> open grain of Siberian elm makes an excellent charcoal though because of
it's
> porosity and lower apparent ash.
>     I suppose we could do this complex analysis of compounds which change
> with the weather.  This is of great use to botanists who are unlocking the
> secrets of Btu. production.
>      The simpler way for most folks, is just to test raw heat value of
what
> material you have, with an understanding of the processes by which those
> values vary.  Start with dry wood and subtract the ash.  Just don't be
upset
> by a 2% variation from your neighbors experiments, it's not worth the
trouble
> to track it down.
>     If 2% is the difference for you, than pay for good feedstock analysis,
> with a very consistent material.  F 1 Hybrid or cutting produced trees
grown
> on plantations, wheat or other grain crops, sugarcane and grasses, all
tend
> to be much more similar in final make up due to the trouble farmers have
gone
> through to make a consistent product.  Just use test samples from the same
> crop to compare apples to apples.
>     Any good chemical analysis avalible of saps and resins?  What is
cherry
> sap Vs maple sap?  How about pine sap Vs spruce?  What is in the high
energy
> sap in locust wood?
>     This will expand the range of chemistry for analysis.
>                                       Daniel Carefreeland(scape) Dimiduk


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