[Stoves] Calculating cooking costs and char costs ----Re: [biochar] Where to discuss STOVES AND CARBON offsets and drawdown

[Frans Peeters]

Paul,

 

   First cracking wood gives H20 out of its O+2H 

Dry wood is called 15% H2O content ……

Wett wood 16-30% H2O ;needs 3 years drying .

Biomass with leaves just cut  60% H20  !

LABO dry means 24 h at 120 °C for 1cm thick .

Analytic  is for definitions .  Charcoal makers may think different .

You get enery from 1Kg wood= 4KWh.

If you like the half now out of your wood,you can it ,during pyrolysis .

You like  the other half out your charcol LATER ….You can ,and evitting rotting !.Get easy distribution .

You NEED enery to get cracking ; but that energy is not LOST …..Use it for something the same time !

 

Regards

F.

 

 

Van: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] Namens Paul Anderson

 

To all.

Thanks for the explanation of 47%C
Something is still not clear:



Beginning with the baseline fuelwood use of 187,800 kg of fuelwood per year per village, if we assume a 10% moisture content, the baseline fuelwood is equivalent to 170,700 kg of dry fuelwood. 

I can accept that.   That is about 5 kg of wood per household per day.



We assume that dry mass can be converted to carbon mass using 47%C (Ryan et al., 2011),

I do not yet accept this (above).   Dry biomass is carbohydrates.   C and O and H, in the approximate proportion  of   CH2O (Tom Reed has more refined proportions, but I cannot find it at this moment) .   H has almost no weight.  The O  (at atomic weight 16) is a bit heavier than C at 12..  So when the O is gone during pyrolysis, about half of the total dry weight (47%) is attributed to carbon.  That much is fine.

But during pyrolysis, almost half of the carbon leaves the scene in the form of pyrolytic combustible gases that include C atoms.  How much of the C gets converted into graphine sheets of charcoal can vary with the pyrolysis temperature.  When pyrolysis is at less than 450 deg C, some of the carbon  still  hangs around in tarry / greasy content inside of charcoal, but it is not the same as the carbon of the charcoal.

So, if the dry  wood is 170,700 kg, and half of the weight leaves as exiting oxygen  atoms, then that would be what the article said was



resulting in 80,240 kgC per year per village.   

But that is the TOTAL of carbon.   About half of that C is gone in  the pyrolytic gases, leaving about 40,100 kg C per year per village.

Did I miss something?   Am I talking about something different?  I am here to learn.   

But if I am correct, what are the implications for the Jagger article?  

Paul




 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20170917/518803de/attachment.html>