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

[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   CH_2 O (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

Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
Email:  psanders at ilstu.edu
Skype:   paultlud    Phone: +1-309-452-7072
Website:  www.drtlud.com

On 9/16/2017 7:14 PM, 'Tom Miles' tmiles at trmiles.com [biochar] wrote:
>
> Paul,
>
> If you do what is called an “Ultimate Analysis” of the dry wood fuel 
> you will get about 47% of the dry weight as elemental carbon. (ASTM 
> method E777-17). The carbon is physically in the form of cellulose, 
> hemicellulose and lignin. When you heat the wood in pyrolysis or 
> gasification you will get about half of the carbon in the form of 
> charcoal. The rest converts to CO, CO2, or other gases.
>
> Tom
>
> *From:* Stoves [mailto:stoves-bounces at lists.bioenergylists.org] *On 
> Behalf Of *Frank Shields
> *Sent:* Saturday, September 16, 2017 4:11 PM
> *To:* Discussion of biomass cooking stoves 
> <stoves at lists.bioenergylists.org>
> *Cc:* biochar at yahoogroups.com; hsmclaughlin at verizon.net
> *Subject:* Re: [Stoves] Calculating cooking costs and char costs 
> ----Re: [biochar] Where to discuss STOVES AND CARBON offsets and drawdown
>
> I think they are referring to converting Organic Matter to Organic 
> Carbon.
>
> For biomass they typically consider about half biomass to be carbon 
> (DAF)).
>
> But then we have some of this loss during combustion so around 25% - I 
> am thinking (DAF basis).
>
> Frank
>
>     On Sep 16, 2017, at 3:49 PM, Paul Anderson <psanders at ilstu.edu
>     <mailto:psanders at ilstu.edu>> wrote:
>
>     tom,
>
>     This quote is from Pam Jagger's article, and cites Ryan.
>
>         We assume that dry mass can be converted to carbon mass using
>         47%C (Ryan et al., 2011),
>
>     What does   "  47%C " actually mean?   That is not the same as  
>     "% yield of charcoal compared to dry-weight of biomass"
>
>     Who can explain such a process with such a high yield of
>     charcoal?    I did not think that it is possible, unless it is a
>     bit beyond torrified wood.
>
>     Paul
>
>     Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
>
>     Email: psanders at ilstu.edu <mailto:psanders at ilstu.edu>
>
>     Skype:   paultlud    Phone: +1-309-452-7072
>
>     Website: www.drtlud.com <http://www.drtlud.com/>
>
>     On 9/16/2017 12:05 PM,tmiles at trmiles.com
>     <mailto:tmiles at trmiles.com>[biochar] wrote:
>
>         We could estimate the potential carbon products and benefits
>         (or costs) from TLUDs using known data from TLUD efficiency
>         tests and real examples. For example, what impact could a TLUD
>         have on the scenario tested in the work in Malawi that was
>         posted yesterday by Pam Jagger?
>
>         “Similarly, the average amount of fuelwood collected was
>         estimated at 1878 kg per year per household, or 187,800 kg of
>         fuelwood per year per village. We relate the fuelwood use in
>         kilograms to hectares to better quantify the regional forest
>         impact. From the rural exposure monitoring data set, we find
>         the average moisture content of the fuel (woody miombo
>         biomass) to be 10%. 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. We assume that dry mass can be
>         converted to carbon mass using 47%C (Ryan et al., 2011),
>         resulting in 80,240 kgC per year per village. A study of
>         carbon stocks in miombo woodland in Mozambique found that
>         woody biomass totaled 33.3 tC/ha (Ryan et al., 2011). If we
>         assume similar composition of woodland, we find that the
>         baseline case results in a miombo woodland deforestation rate
>         of approximately 2.41 ha per year per village.”
>
>         What impact could a TLUD have on 1878 kg/household per year?
>         How much biochar/charcoal would be produced and at what value?
>
>         Health Alert: Reading Pam’s paper could raise Nikhil’s blood
>         pressure. : - )
>
>         Tom
>
>

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