[Terrapreta] FW: [Stoves] Biomass Cooking Stoves Site in Back Online / wood vinegar/ --C.ADAM

[Tom Miles]

Here are the messages by Chris Adam (Germany) and Dr. AD Karve (India) on
the charcoal making workshop held in Pak Chong, Thailand by the Asian
Regional Cooking Stoves Program (ARECOP). 

-----Original Message-----
From: stoves-bounces at listserv.repp.org
[mailto:stoves-bounces at listserv.repp.org] On Behalf Of adam u partner
Sent: Monday, March 12, 2007 12:52 AM
To: Discussion of biomass cooking stoves
Subject: Re: [Stoves] Biomass Cooking Stoves Site in Back Online / wood
vinegar/ --C.ADAM

Tom Miles schrieb:

Dear Tom,
we were overwhelmed at the ARECOP workshop from the diversity of 
products which are available in Japan on the base of charcoal
(made mainly out of hard-bamboo-charcoal powder):
charcoal soap
charcoal shampoo
charcoal pillows
charcoal pads (for the smell in the fridge)
charcoal air ionizer
-----
Wood vinegar for ECO farmers, (Insecticide)
for improving the soil,
for spraying on the plants as a kind of growing hormone (?)
for being mixed with charcoal power and added to the chicken and pig 
food, no smell any more from the pigs, dark meat without grease etc., etc.
The wood vinegar was distilled- if used for animals or human.
----
Its also the 1st time I did hear about "white charcoal" = "Kishu 
binchotan". Its charcoal which is strong like glas(?) and sounds like 
metal or glass when you tap it.
You can not cut this charcoal by a metal saw(?). The bark stays 
connected with the wood kernel.
To produce it- you raise the temp. very slowly (1°C/h?), over 10 (?) 
days or so,
at the end the kiln or retort is opened shortly and the charcoal gets a 
final (?) heat shock (1000°C or even 1300°C?)
also a certain wood (kind of holm oak?) should be used.
But there is still some mystery in its production and the best pieces 
(long and thin pieces like a walking stick!) are kept like collection 
pieces (..Today, Japan's charcoal-making techniques are admired worldwide..)
WHAT    i     LEARNED:
i always promoted my  "Low-cost retort kiln" to make rapidly charcoal 
(starting in the morning at 7, getting the water out during the 
following approx. 5 hours,
burning and recycling the volatiles of the wood gases during the 
afternoon, finishing carbonization at aprox. 7 in the evening, cooling 
at night.
3 batches can be done per week à about 250kg each  (from about 3m3 
volume and about 750kg wet wood or 600kg dry wood)
= aprox. 750kg of charcoal per week.
Now, for getting extra-strong charcoal i would recommend to get the 
water out more slowly, one day, one night, starting wood gasification 
and charcoal the next morning,
finishing carbonization in the early afternoon, cooling late afternoon 
and night.
Still 3 batches per week Mon/Tues + Wed/Thur + Fri/Sat. can  still be 
obtained (= aprox. 750kg of charcoal per week).
I also would add a device in the construction  of the retort to enable 
to open the wood chamber at the end and raise the temperature above 
600°C and more for the "refinement"
of the charcoal.
Best
Chris
>  
> AD,
> Thank you for the report from Pak Chong. It sounds like you may have found
a
> good use for torrefaction. As you may know there is a group in the
> Netherlands that has been promoting torrefaction for making fuel pellets. 
>
> I also enjoyed your comment about the wood vinegar. Was there any
discussion
> at Pak Chong about the use of the charcoal itself as a soil amendment for
> growing crops? Ron Larson convinced me to create a discussion list and
> website on Terra Preta http://terrapreta.bioenergylists.org or the
> intentional use of charcoal in soil. Terra preta is the portuguese term
for
> black soil and derives from the practice in the amazons where charcoal was
> blended in soil. We have had discussions about terra preta here on the
list
> in the past. It is used in various forms with rice husk charcoal in Japan.
> Ron has always wanted to make a gasifying stove that would produce
charcoal
> that could be used in a planting hole. Have you tried using charcoal to
> improve crops? With the wood vinegar?
> Kind regards,
> Tom
>
> -----Original Message-----
> From: On Behalf Of adkarve
> Sent: Tuesday, March 13, 2007 6:30 AM
> 
> I am just back from a workshop organised by Asia Regional Cookstove
> Programme (ARECOP) in Pak Chong, Thailand. I take this opportunity to let
> the stovers and members of ETHOS get acquainted with the valuable work
being
> conducted by ARECOP in the South East Asian countries.Theme of this
> particular workshop was making high grade charcoal. A large variety of
kilns
> was demonstrated during the workshop by their respective users/inventors.
> The coal made in these kilns was hard. It had a metallic sound when hit
> against a hard object. It contained 95% carbon, had high electrical
> conductivity and a high calorific value. This carbon is used as a
supplement
> in animal feed. It improves the quality of meat and it reduces the smell
of
> the dung. In Japan they add this coal even to human food, to skin
ointments
> and hair tonics. The hard coal, if burned in a properly designed stove,
can
> generate temperature above 1000 degrees. The yield of charcoal from most
of
> the kilns was less than 30 percent. This means, that almost 75% of the
> energy in the wood is wasted when we convert wood into into charcoal.A
> valuable byproduct of these kilns was wood vinegar. It sells at about US$6
> per litre. Wood vinegar is used as an agricultural pesticide and also as a
> plant growth promoting agent. The name wood vinegar is misleading. It is
not
> used as a salad dressing. In fact, it contains certain carcinogenic
> chemicals. I was invited as a resource person and I demonstrated our
> oven-and-retorts process for charring agricultural waste and our extruder
> made from a meat mincer for extruding the char into briquettes. I hope
that
> I made an impact on the trainees. One Dr. Shreedhar from Indian Institute
of
> Science, Bangalore, India, also attended the workshop as a resource
person.
> He talked about torrefiying wood. After his lecture, I conducted an
> experiment with the help of the trainees to torrefy leaves with the
> oven-and-retorts  kiln that was constructed in Pak Chong as a
demonstration
> model. Leaf litter collected from underneath the local trees could be
> torrefied very easily by using my kiln and the torrefied material could
also
> be easily extruded into briquettes. The briquettes burned like wood with a
> tall flame and they also produced smoke, but this process opens up the
> possibility of converting dry leaves of sugarcane and other agricultural
> waste into fuel that can be used in a T-LUD type of stove. The residue can
> still be used as charcoal.
> Yours
> A.D.Karve
>
>   
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