[Stoves] Spherical Cow Dung Balls for ND-TLUDs in Bangladesh

[Julien Winter]

Hello  Roberto et al.;

The spherical balls used in the Akha "Agriculture-Friendly Stove" (to use
its full name) are made with 50% (w/w) cow dung and any chopped biomass.
Informal tests have been done using mustard husk, water hyacinth, rice
husk, maize cobs, rice straw, tree leaves, sawdust.  I have seen a report
from Pakistan were cow dung was 25% of a biomass brick.

Cow dung is quit high in ash.  Thirty-five percent ash is not uncommon, but
it depends on what the cow has been eating.   In a ND-TLUD, the char yield
can be as much as 50% of the original air dry mass of dung, because of the
high ash content.  Mixing in biomass increase the energy content of the
fuel.

In India, the energy content of cow dung is higher than Bangladesh, because
Indian cows eat plastic:
http://www.karunasociety.org/the-plastic-cow-project

Cow dung balls are being used in Bangladesh, because there is not enough
fire wood to burn for cooking all year round.  Since ND-TLUDs require dense
fuel, the cow dung balls augment the wood.

Bangladesh has two main seasons, a dry winter and a wet summer.  Rural
people tend to burn sun-dried leaves and straw in the dry season, and
conserve the wood for the wet season.

The Akha "Agriculture-Friendly Stove" burns about 35% less fuel than a
traditional cookstove (that looks like a clay volcano, with a side port for
stoking).  Any kind of compressed fuel will help to extend the use of the
"Agriculture-Friendly Stove"

We need to develop village-made compressed fuels in Bangladesh.  We have
made balls with paper, but we are uncertain about the weather the ink dyes
contain heavy metals.

Has anyone tried algae as a binder?

Baojun Yi, Qiaoxia Yuan, Hongliang Cao, Ming Wang, Wenjuan Niu, Shuiping
Yan. 2018.  Combustion Characteristics of Densified Cattle Manure Briquette
in an Isothermal Condition.  BioResources 13(2):3571-3584
can be downloaded from
http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_13_2_3571_Yi_Combustion_Characteristics_Densified_Cattle_Manure

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/20181101/f4ff4b2b/attachment.html>