[Terrapreta] a low-cost low-pollution barrel charcoal maker

[Gerald Van Koeverden]

Dear Bakaryjatta,

it sounds like your design is more efficient with less pollution than  
the M.I.T. barrel carbonizer.  (Their sugarcane carbonizer handbook  
(365KB) is at:  http://web.mit.edu/d-lab/portfolio/ 
sugarcanecharcoal.htm )

Whether or not an ideal design for a DIY barrel retort charcoal maker  
is economical or not for developing countries, we should work towards  
that goal.  What are the essential characteristics of such a design?

1.  An efficient heater:  there's a ton of designs of low-cost so- 
called super-efficient stoves on the Web.  This list alone, has a few  
participants who are designers of such stoves.  Surely we can come  
with a suitable one to sufficiently heat a barrel of biomass that not  
only utilizes hard fuel but also the gaseous waste from the barrel  
retort?  Who can recommend their design, or another's, for this  
task?  Who can figure out how to integrate that design efficiently  
with a barrel retort?

2.  An efficient retort:  it should be insulated, not only for energy  
efficiency, but also for quality - the more its insulated, the more  
evenly will the heat be distributed inside.  This insulation need be  
no more complicated than a six inch wall of soil surrounding the  
barrel, or a coating of??

The first step is the stove-barrel design.  Any concrete suggestions  
on which stove to use, and how to integrate it physically with the  
barrel to heat it and utilize its waste gases?

Gerrit




On 24-Mar-08, at 7:09 PM, bakaryjatta wrote:

> Dear list members,
>
> At great cost of telephone bills andISP charges I tried to keep up  
> with the
> postings, hoping to find something practical beyond what I am doing  
> myself
> right now.
>
> Unfortunately I see long repetitions of previous posts and stuff  
> that does
> not edify matters in the least, but rather confused what appeared  
> to be a
> straight forward thing.
>
> My retort is in my back yard. It is a drum with a fairly tight lid  
> and a
> piece of pipe letting volatile gasses take over the initial firing  
> in the
> firebox underneath. The drum is enclosed in a rock and soil and  
> lime plaster
> wall. For a quick start I surrounded the drum with small branches  
> or crop
> waste before covering the top with a scrap iron sheet with a gap  
> for smoke
> to escape in the beginning. The drum costs money, the rest is labor.
>
> The biomass is crop waste and or tree trimmings. Some material is  
> up to 50
> mm thick and still chars all through. Like was stated on the list,  
> the char
> appears to be about 40 %. After initial smoke, the volatiles take  
> over and
> burn with a roaring sound. Sorry, no analysis of the off gasses,  
> but I trust
> I am not a poluter beyond the normal CO2. With adequate investment the
> excess gas or heat can be utilized, not likely an easy option for  
> most third
> world farmers.
>
> Where does all the biomass come from? Plant it!  People still get  
> rid of
> lots of it to clear roadsides and farms here. OTOH, I am planting more
> biomass every year and my soil is improving in the process. My mini  
> climate
> is improving too as many of the trees retain their leaves during  
> the dry
> season . Jatropha curcass is a soil improver and wind break. Not  
> useful for
> char, but it makes great fuel oil for lamps and soap making. The  
> oil cake
> makes good methane gas for cooking.  The digester effluent is mixed  
> with the
> bio char before it put in the planting holes on the field.  Soil  
> improver,
> energy and soil micro-organism inoculant.
>
> Is it economic? What is the meaning of that? Maybe, when I get a good
> harvest, which depends on many other factors, like rain, etc. After  
> all,
> food prices are going up because of increasing scarcity. Maybe some  
> people
> think they can eat their economic gain in the form of money. During  
> the last
> world war money could not buy food that was not there! You think the
> government is going to regulate food production to assure economic  
> gain and
> sustainability? Or the market place will be regulating the climate  
> in a
> timely fashion so that harvests will be reliable. My conclusion is  
> that the
> real value is the food and other resources provided by the life of  
> the plant
> springing from the soil.
>
> Why am I doing this?  I think it is a usefull thing to do. There was a
> quotation that I recognized as true: 'The Spritual precedes the  
> material'
>
> The economic consideration will not bring a solution. It has in  
> fact been
> the cause of the problem!
>
> So, considering economic criteria, maybe no present value seen  
> yet , but the
> net value will be having a future worth having at all. It is a  
> choice and it
> better be a collective choice. If it does not do all as expected,  
> do we lose
> anything?
>
> Kind regards,
>
> Bakary Jatta
>
> Bwiam village, WR
>
> The Gambia
>
>
>>   1. Re: Net Present Value and Net Future Value of TPBenefits
>>      (Greg and April)
>>
>>
>>
>
>
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