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| Stoves Archive for January 2002 |
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| 240 messages, last added Tue Nov 26 17:31:21 2002 |
[Date Index][Thread Index]
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Incidentally your friend was correct that charcoal making is approximately
driving off the water... Using the above formula I get
C H1.4 O0.6 = C 0.6(H2O) H0.2 ==> All the degrees of charcoal in the order
Torrefied wood; Sea Sweep (oil absorbent); Cooking charcoal; mettalurgical
charcoal; activated charcoal
corresponding to driving off 0.1, 0.2 etc. waters.... at temperatures of
275; 360; 425; 600 and 800 C.
Yours truly, TOM REED
In a message dated 1/3/02 11:22:40 PM Mountain Standard Time,
pverhaart@optusnet.com.au writes:
>
> Stove dried wood contains about 50% carbon (at least I think that was the
> rule of thumb we adopted). Next we assumed the rest was H and O in the
> proportion of water. This gives .
> Nobody suggests this is accurate but works in the world of stovers.
> There was a staff member at Eindhoven (not in our faculty, I am happy to
> say), who explained the charcoal making process as driving off the water.
> If things were only that simple.
>
> Piet
>
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Content-Type: text/html; charset="US-ASCII"
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<HTML><FONT FACE=arial,helvetica><FONT SIZE=2>Dear Piet and all:
<BR>
<BR>Your formula
<BR>
<BR>C3 H4O2
<BR>
<BR>suggests that we have a single molecule like cellulose, C6H10O5. We don't. Therefore I suggest you use a "ratio formula" giving the ratio of hydrogens and oxygens to one carbon, or
<BR>
<BR>C H1.33 O0.66
<BR>
<BR>However, Prof. Ray Desrosiers in 1979 made an extensive study of lots of biomass species and came up with
<BR>
<BR>C H1.4 O0.6 (quite different from the one you gave)
<BR>
<BR>I have used this for 20+ years and found it is very close for all species of wood and most species of other biomass on a dry, ash free basis.
<BR>
<BR>For instance, you can write the biomass combustion equation
<BR>
<BR>C H1.4 O0.6 + 1.05 (O2 + 3.76 N2) ==> CO2 + 0.7 H2O + 3.95 N2
<BR>
<BR>From this you can calculate that the air/fuel ratio for stoiciometric biomass combustion is 6.3. (Perfect adiabatic gasification is then 1/4 of that). etc. etc.
<BR> ~~~~~~~~~~~~~~~
<BR>Incidentally, I am soon going to re-issue the 400 page book published at that time which still exceeds most of what I find written today.
<BR>
<BR>Incidentally your friend was correct that charcoal making is approximately driving off the water... Using the above formula I get
<BR>
<BR>C H1.4 O0.6 = C 0.6(H2O) H0.2 ==> All the degrees of charcoal in the order
<BR>
<BR>Torrefied wood; Sea Sweep (oil absorbent); Cooking charcoal; mettalurgical charcoal; activated charcoal
<BR>
<BR>corresponding to driving off 0.1, 0.2 etc. waters.... at temperatures of
<BR>275; 360; 425; 600 and 800 C.
<BR>
<BR>Yours truly, TOM REED
<BR>
<BR>
<BR>
<BR>In a message dated 1/3/02 11:22:40 PM Mountain Standard Time, pverhaart@optusnet.com.au writes:
<BR>
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">
<BR>Stove dried wood contains about 50% carbon (at least I think that was the
<BR>rule of thumb we adopted). Next we assumed the rest was H and O in the
<BR>proportion of water. This gives .
<BR>Nobody suggests this is accurate but works in the world of stovers.
<BR>There was a staff member at Eindhoven (not in our faculty, I am happy to
<BR>say), who explained the charcoal making process as driving off the water.
<BR>If things were only that simple.
<BR>
<BR>Piet
<BR></BLOCKQUOTE>
<BR>
<BR></FONT></HTML>
--part1_b7.19819873.2968f99b_boundary--
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