[Stoves] Spherical Cow Dung Balls for ND-TLUDs in Bangladesh : Dung is very do-able

Nikhil Desai pienergy2008 at gmail.com
Sat Nov 3 10:13:54 CDT 2018


This "fertilizer v. fuel" debate is decades old and without resolution.
Fertilizer use is probably superior, as is shifting away from livestock for
non-food uses. Whether higher efficiency saves forests or soils is
indeterminate; too many confounding variables.

I learned my energy economics by doing village biomass balances in support
of a paper (by Russ deLucia) titled something like "Food, feed, fuel,
fertilizer" and adding other Fs over time - fence, furniture.

There was a chemistry question I never got around to researching, so I ask
here: Are these tradeoffs contextual, in the sense that animals in a
particular ecosystem produce wastes that are in balance with those
particular soils and crops? What happens when the village boundaries are
disturbed - from import/export of food, feed, fuel, fertilizer?

This is not an academic question. I remember also the controversies about
monoculture farming and forestation, water requirements, changes in soil
conditions and employment practices. One such was eucalyptus on hills
around Addis Ababa - an idea of the recent stove evangelist (and aDALY
promoter) Ken Newcombe. Eucalyptus in fuel use had to be limited to injera
mtads, which market was quickly captured by electricity, both at home and
commercial establishments. Eucalyptus wasn't good for making charcoal, so
the economics of charcoal production, distribution, and use in Addis were
transformed. (If I remember correctly, somehow charcoal stoves were not
used for injeras.)

While I respect all technical accomplishments of yours and others, I am
convinced that biomass use is fundamentally a matter of chemistries -
agronomy to food chemistry to animal biochemistry - and economics -
ownership of biomass, the politics of village control. Mere technology is a
red herring.  In the broad scheme of things, technologists have failed; I
could argue that they were made to fail, by incompetent energy and rural
development planners and financiers.

There are many biases that put up barriers against a single technology.
Around 1990, deLucia turned to a "village energization" paradigm, and a few
years later, the World Bank electric power staff coined "rural
transformation" argument for electrification. Common to both is the idea
that technological change is a multi-dimensional economic process - many
technologies change simultaneously, affecting the whole village biomass and
energy balance (along with transport of goods and labor). Nobody knows how
to ignite transformation without electricity and fossil fuels, so biomass
energy technologies remain in the compost pit by and large.

Nikhiil
------------------------------------------------------------------------
Nikhil Desai
(US +1) 202 568 5831
*Skype: nikhildesai888*



On Fri, Nov 2, 2018 at 9:39 PM Crispin Pemberton-Pigott <
crispinpigott at outlook.com> wrote:

> Dear Dung Dippers
>
> On Julien's last point, the Ag Ministry in Tajikistan has been concerned
> about burning dung instead of putting it on the fields. Because of a near
> complete loss of tree cover and zero planting, many people who used to heat
> and cook with wood now use dung which is prepared in thick centered 'pies'
> a little larger than a dinner plate, 60mm thick, tapering to the edges.
>
> Because of there being no quick solution to the fuel supply issue, the
> best thing to do is to reduce consumption be changing the stoves.
>
> Because of the poor design of the traditional heating stoves it is widely
> believed that dung cannot burn on its own so it is invariably mixed with
> some twigs like cotton stalks or coppiced ‎wood. Many fields are lined with
> trees trimmed for coppicing.
>
> A technical assistance project assisting Caritas Switzerland took place in
> early 2016 and resulted in two new stove designs intended to burn dung
> alone, at a high enough heating and cooking power to match or exceed the
> standard performance. These two models, initially dubbed Model 1 and Model
> 2 (there were four more in the set) came in two iterations each: with and
> without a cooking pot hole.
>
> The traditional way to burn dung is extremely smoky and requires attention
> about every 15 minutes ‎to add a small amount of fuel.
>
> The two new models adopt the combustion system used on a Mongolian stove
> known as the MM2 which was an end-lit crossdraft burner with a flame tube
> between the fire chamber and the heat exchanger.
>
> The TJ2.0 was adapted later to become the much more powerful KG2.5 for use
> in the mountains where it drops to -30 C.
>
> The fire is ignited at the far end of the fuel chamber directly in front
> of the flame tube (usually 3" pipe) and the fuel stacked around to and
> towards the door at the 'front' of the stove. There is a grate.
>
> The door has within it an air controller. There is no other air entrance.
> This arrangement also has the cooking station on top of the area in which
> the fire is lit, immediately next to the flame tube entrance. With a good
> draft from the chimney, the fire is quite intense and as the fuel is
> burning from the hot zone into the fuel stack, it is a sort of TLUD on its
> side. Cooking power is admirable, much higher than the traditional stove
> with mixed fuel.
>
> The fire is indeed very smoky, but all that goes into the fame tube and a
> substantial fraction of it is combusted inside the pipe. Apart from cooking
> over the fire, people cook on top of the heat exchanger as the temperature
> of the plate is over 300 C. It is certainly hot enough to heat a 20 litre
> container of water.
>
> The end result is a stove which will burn dung alone, or the twig fuel
> alone if you have it, under conditions controlled enough to limit the
> excess air and maintain a very hot fire zone no matter what the fuel.
>
> Fuel consumption is down 40-50% de‎pending on the home. They no longer
> have to buy twig fuel to co-fire, and there is more fertilizer available.
> The minerals are preserved in that the ash is tossed onto the fields.
>
> All the drawings and many photos are available at
> www.newdawnengineering.com in the Library, Stoves, [country] and [model]‎.
>
> Regards
> Crispin
>
>
>
> They are formed by hand and stuck onto a vertical wall to dry. So they are
> sticky.
>
>
>
> Hello Richard;
>
> What do you give a cow with diarrhea?  .... (answer at the end)
>
> Thanks for your advice.  I have visited www.legacyfound.org
> <https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.legacyfound.org&data=02%7C01%7C%7Ccc76cfb043924cab96c008d6411c5456%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636767987254576473&sdata=8yxyEt%2BTVMgbu2o6a%2BgYee9no5CUUb7wiCGohZfQ6oI%3D&reserved=0>
> in the past for ideas on making briquettes.
>
> In a past life, I spent at time at the south end of many cows facing
> north, but I never gave much thought as to what part of manure was sticky.
>
> I would not have expected the fiber to be the sticky part.  If the solutes
> and fine suspended particles can be removed, and the fiber used as a
> binder, that would be excellent!   The leachate could be combined with
> biochar.  Removing nitrogen from the fuel would reduce gaseous losses of
> N.   I have always been sorry to see good manure fertilizer burned.
>
> .... A lot of room.
>
> Cheers,
> Julien.
> --
> Julien Winter
> Cobourg, ON, CANADA
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20181103/6f0bcdf5/attachment.html>


More information about the Stoves mailing list