[Stoves] Aside on coconut husks- continued

[Michael N Trevor]

Green nuts are a very improbable fuel source. They are available almost
exclusively only from harvesting
drink nuts which means climbing the trees. It is true that the green husk
are relatively easy to cut and split.
but difficulty getting it and limited supply are major issues. It is also
very wet and damp requiring
weeks to dry.

The Brown dry ones one are what most people are dealing with. These are
mature nuts which have fallen to the ground.
These are the normal nuts harvested for copra making or even grated coconut
as eaten. The nuts are husked by being force down on a sharp stick or pipe
and twisted to split the husk. It take no more than a few seconds per
coconut and a skilled copra make usually removes the husk
in three section which are still semi attached to each other. For fuel these
are generally or rent or split into separate sections and sun dried.
and by the bag full are no where as light as they might appear. They are
also remarkably tough as anyone who has receive a gift coconut
from Florida, the Bahamas, or Hawaii can attest. These people usually spent
the next several hours trying to split and tear the husk
off . Many people end up doing little more than ripping the husk off shred
by shred with pliers to finally reach the coconut inside.
To see some one actually husk a nut with a husking stick is total
revelation.

Copra making in itself is brutally hard work requiring gathering hauling
husking cracking and drying of thousands of coconuts per
ton. Moving it around means carrying sacks that often weigh well over a 100
pounds each and there repetitive motions in cracking
and cutting coconut meat from the shells that would delight a repetitive
motion injury specialist. Thing is when all the work is done
cubic yards of husks left over. In most rural areas it is simply burned to
dispose of it so air pollution, and soil degradation are the end result.
So we come full circle back to how to better use it as fuel or even char it
as a potential terra preta medium.

Michael
Enemanit





----- Original Message ----- 
From: "Paul S. Anderson" <psanders at ilstu.edu>
To: "Discussion of biomass cooking stoves" <stoves at listserv.repp.org>;
"Michael N Trevor" <mtrevor at ntamar.net>
Sent: Thursday, April 12, 2007 12:51 PM
Subject: Re: [Stoves] Aside on coconut husk


> Michael and all Stovers,
>
> If the dry coconut husks yield a smokey traditional fire, that is of
little
> consequence for the TLUD gasifier usage of husks.  TLUDs as gasifiers are
> constructed to produce smoke and then SEPARATELY burn the smoke.  More
smoke
> yields more flame.
>
> The gasifier flames are NOT at low temperatures, so Michael's comments
> about the
> advantages of the low temperature husk burning will not be available via
the
> gasifiers (except that the cook can move the pots, etc away from the
direct
> flames).  We will need to experiment to determine how much "turn down
ratio"
> can be achieved in a TLUD that has coconut husks as fuel.
>
> Michael wrote:
> > As for moisture content in husk, it is highly variable. It is nearly dry
in
> > relatively fresh unhusked nuts.
>
> I have seen dry, very brown coconuts.  Are you referring to these nuts?
>   And are
> those the nuts that are desired for harvest and processing?  To me, the
dry
> brown husks are hard to cut.  Am I correct about this and about the next
> paragraph?
>
> In contrast, when the un-cut nuts have high moisture and greenish
appearance,
> the large knife can cut the husk easily, giving nice pieces that will dry
and
> be correctly sized fuel for the TLUD gasifiers.
>
> A TLUD gasifier specifically for coconut husks will probably have a
> diameter of
> 8 or more inches (20 or more cm).  Therefore, the fuel size can be larger
> chunks than for the smaller diameter TLUDs that are burning wood chips or
> coconut shell pieces.  The husk pieces could be in sizes between 1 inch
cubes
> to 3 inch cubes, or any irregular sizes that have no measurement
> greater than 4
> inches.  These should be easy to make with a machete.
>
> What is the common practice in the Marshall Islands for cutting off the
husks,
> and how many days of drying?
>
> Paul
>
>
> -- 
> Paul S. Anderson, Ph.D., Geography professor - Emeritus
> Telephone:  USA-309-452-7072 (residence and office)
> Internet site:  www.ilstu.edu/~psanders
> For my gasifier stoves info, go to:
> http://bioenergylists.org/contributors#Paul_Anderson
>
>
> Quoting Michael N Trevor <mtrevor at ntamar.net>:
>
> > Coire are the fibers in the husk. Industrially today in general husks
are
> > mechanically beaten
> > and pounded to release the fibers and pith from each other. The fibers
are
> > combed to separate
> > the pith. The fibers have many uses and the pith can be recycled into a
> > masonite like press board.
> > Even Mercedes Benz was making use of coconut husk materials. Here in the
> > Marshall Islands
> > retting was carried out to obtain the coire fibers to hand twist the
ropes
> > and twine needed to
> > construct and sail the traditional canoes.
> >
> > As for moisture content in husk, it is highly variable. It is nearly dry
in
> > relatively fresh unhusked nuts.
> > Once coconuts are husked and the interior exposed they can reach 100%
> > saturation.  Therefore after
> > husking the sun drying of split pieces of husk as fuel is common. The
> > picking up, hauling,  drying, and storing
> > requires considerable time and effort on the part of women and girls.
> > However, discounting labor it costs
> > little.  While it is low in heat value, its plentiful nature and being
> > essentially "free" make it a preferred fuel.for
> > many here. In spite of its volumous smoke output,  dry,  it is actually
is
> > good fuel for certain uses: its low temperature makes
> > it good for not burning rice soups and stews. Roasting breadfruit is
best
> > done on husk too, wood coals and charcoal
> > are too hot. This results in a quick burning of the outside while not
> > allowing enough heat to penitrate and cook through
> > into the center portions.
> >
> > Culturally it is interesting to note how people have adapted and used
their
> > resources and the "3 stone fire" to take advantage
> > of what they have available. As we proceed working on better stoves,
which
> > certainly have myriads of good uses and benefits
> > there maybe local practices that need to be considered as well to
facilitate
> > adoption.
> >
> > Michael N Trevor
> > Enemanit.
> > Marshall Islands
> >
> >
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> >
>
>
>
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