[Terrapreta] Farm Scale Batch Charcoal Furnace for Homestead or Farm

[Gerald Van Koeverden]

AJH,

The Peko Pe stove produces char, and can sized up easily to a 200  
litre drum. http://www.pekope.net/energy_unit.html

  Is that sort of what what you were thinking?

Gerrit


On 6-Apr-08, at 1:30 PM, andrew wrote:

> On Sunday 06 April 2008 11:05, David Stewart wrote:
>>  My interest runs to using wood as a biomass source
>> (I am located in the Northeast US) both for heat and for agrichar
>> and biogas.
>
> It's a shame you're about 4000 miles away, charcoal heat and power is
> something I've been interested in for a few years, my colleague
> managed to get as far as running a gas turbine (with support fuel)
> off the offgas (biogas tends to be interpreted as the gas given off
> by the anaerobic digestion of volatile solids and is a mixture of
> CO2 and methane).
>
>> The primary attribute of
>> this furnace would be to create the biochar in a chamber separate
>> from the heat creation chamber.  This would allow for easy
>> extraction of biogas and efficient use of the wood being burned in
>> the combustion chamber when not being used to heat the house...
>
> The thing about the offgas from a retort/kiln is that it is
> quite "dirty" being a mixture of tarry vapours as well as gases like
> methane and CO, so piping it any distance is problematical.
>
> If you use a wet (hydronic) system then you can take this heat after
> it has done some work for you in pyrolysisng the wood, which is
> happening at between 270C and 500C, depending on what sort of char
> you're after, so taking heat out at 95C makes a later call on it.
> This hot water can be a fairly inexpensive thermal store to even out
> fluctuation between batches.
>
> The trouble with a batch system will be in reconciling the heat from
> the flaring of offgas with the earlier need for it to heat the
> retort. A Russian chap, Yury, from the [stoves] list gets around
> this by loading large cassettes of prepared logs sequentially into a
> kiln, so that the heat from a pyrolysing batch initiates pyrolysis
> in the new batch.
>
> I cannot see any real need for running as a batch, especially as
> there is no need for the char to be large particles or dry. Why not
> a simple downdraught chip burner but with the char withdrawn before
> it gets oxidised to CO?
>
> How about some figures for heating requirements and an idea of the
> raw material you are considering?
>
> AJH
>
>
> _______________________________________________
> Terrapreta mailing list
> Terrapreta at bioenergylists.org
> http://bioenergylists.org/mailman/listinfo/ 
> terrapreta_bioenergylists.org
> http://terrapreta.bioenergylists.org
> http://info.bioenergylists.org