[Stoves] Bagasse Briquette Work

Tue Oct 12 07:13:36 CDT 2010

Dear Miss Tiwari,

I believe DR. A.D. Karve of ARTI found an effective means of making charcoal
from sugar cane trash,  which could then be ground and formed into
briquettes with a suitable binder.

I am not sure whether Dr. Karve went on to try this process with bagasse -
but the technique may be applicable.

I am not aware of a non carbonising method for processing bagasse into
briquettes - however others on this list,(notably Richard Stanley et
al.) have experimented with simple presses to make "holey" briquettes from
assorted raw biomass.

http://www.bioenergylists.org/taxonomy/term/243

http://www.repp.org/discussion/stoves/200109/msg00002.html

Carbonising the waste is very often the approach used, because it drives off
moisture and volatiles and leaves an embrittled product which is much more
easily mechanically processed, with a more uniform composition and calorific
value. Plus with the advantage that the energy density is much improved.

The energy lost in the volatiles during the carbonisation process can be
recouped for drying or torrefying the waste.

There is rising interest in biochar, you might wish to look at the BEK
biochar reactor which could be used to produce charred bagasse on a pilot
scale.

http://www.gekgasifier.com/2009/08/apl-releases-bek-biochar-experimenters-kit-new-videos/

regards

Ken Boak

Try this link

http://www.bioenergylists.org/taxonomy/term/31

Here is the text that describes Dr. Karve's process

Second question: The process described is for sugae cane trash -- leaf --
should it also work on bagasse??

Here is some of the text:

The Ashden Awards, 2005

First Prize - 2002

Converting sugar cane trash into domestic fuel.

Appropriate Rural Technology Institute, India

Summary of the Project

Every year the sugar cane fields of Maharashtra State in India produce a
staggering four and half million tonnes of leaf waste. As the cane is
harvested, the farmer is left with a mass of leaves known as 'sugar cane
trash'. The leaves are full of lignin and silica, so don't decompose easily
and are no good as food for cows. Traditionally, the answer has been to get
them out of the way by burning them.

The Appropriate Rural Technology Institute of India (ARTI) has come up with
another solution. It has developed a special kiln that puts the leaves to
good use by converting them to charcoal powder. The powder is then formed
into briquettes that can be used as fuel for domestic stoves. ARTI
estimates that a rural family could make 100Kg of char-briquettes a day and
so earn 3,000 Rupees (approx £35) a week by selling them on.

Charring the sugar cane trash in kilns instead of burning it in the open is
helping to keep the skies clear and is reducing unnecessary carbon
emissions.

ARTI has also developed a new, improved, cooker that can use these
briquettes as fuel. This 'Sarai' cooker uses only 100g of briquettes to
cook food that would normally need 3Kg of firewood.

The aim of this project is to increase the production of briquettes from
sugar cane trash and to popularise the use of briquettes for cooking.

The need for the project

Charcoal has always been a favourite fuel for cooking with in Maharashtra.
It burns cleanly, produces little smoke and has traditionally been cheaper
than petrol products like kerosene. In the 1950s, the government of India
banned charcoal production and subsidised the price of kerosene in order to
try and stop deforestation. The ban on charcoal making (from wood) is still
in place, but in 2000 the Government reduced the subsidy on kerosene,
forcing people to return to using wood as fuel. The production of charcoal
from sugar cane trash therefore provides a much-needed source of cheap
fuel. The briquettes are expected to displace the use of about 30 times
their weight in wood. This could mean saving about 15,000 hectares of dry
deciduous forest a year in Maharashtra alone.

As mentioned above, sugar cane leaves are extremely tough and won't
decompose easily. They are long and springy and the farmer has to get them
out of the way before ploughing and replanting can begin. The burning of
four and a half million tonnes of sugar cane trash in Maharashtra each year
produces a massive amount of smoke and atmospheric pollution.

Key features of the project and technical information

The first kiln that ARTI built was fixed to the ground, but more recent
versions are portable and can be taken to the fields as they are ready for
clearing. This is an important improvement as collecting up the trash and
taking it to a kiln is not economically viable.

The leaves are packed tightly into lidded stainless steel cans. Seven of
these are loaded into the metal drum that forms the body of the kiln, and
supported by a grate. Sugar can trash is burned below the grate and used to
fire the charring process. Flue gases are forced to move between the cans
on their way to the chimney, transferring their heat as they go.

Being starved of oxygen in the lidded cans, the cane trash is forced to
pyrolise rather than burn as it heats up, and so it turns into a mass of
charcoal. An innovative twist to the kiln design is that a small hole in
the bottom of each can allows gases produced in the process of pyrolysis to
escape at the level of the grate and be burned as fuel. This reduces
atmospheric pollution and means that the charring process is exceptionally
efficient.

It takes 45 minutes to fire one load of trash. At this rate one kiln,
working full time, would take 40 days to char the trash from a one-hectare
cane field. The farmers are generally in a hurry to get their fields
cleared, so the project usually puts 10 kilns into a field at a time. The
harvest lasts about five months, and after that the kilns can be used to
char other things like wheat straw and leaf litter.

At the end of a firing, the cans contain a charcoal mass that needs to be
pulverised with a light roller and then mixed with a liquid binder before
being formed into briquettes. Starch paste, made from the floor sweepings
of flour mills, cattle slurry or sugar cane juice can all be used as
binders. The resulting charcoal paste is pushed into briquette moulds or
extruded from a hand-operated briquette extruder, and left out in the sun
to dry.

Briquette making can only be done when the sun is strong enough to dry the
briquettes. Good sun usually lasts for about 35 weeks a year. During this
time a family could make enough briquettes to earn about 100,000 rupees,
equivalent to the annual salary of an urban white-collar worker. This would
clearly make a dramatic improvement to the quality of life for a rural
family.

As mentioned above, ARTI has developed a new stove, the Sarai cooker, which
uses the cane trash briquettes. The Sarai uses a neat system of three cans
stacked inside a large cooking pot. A small amount of water at the bottom
of the large pot quickly turns to steam and cooks the contents of the cans.
Rice, beans and vegetables can be cooked in one go. The Sarai system has
proved popular, and cookers are now being produced on a commercial basis in
the city of Pune. They are marketed through a rural cooperative at a price
of 350 rupees (about £5).

At present the kilns are not being produced on a commercial basis because
of their cost (one kiln costs about £250 to make), but are made on request
by one manufacturer.

Contact details

Contact name: Dr A. D. Karve

Address: 2nd Floor, Maninee Apartments, S. No 13, Dhayarigaon, Pune,
Maharashtra 411041, INDIA

Telephone: + 91 20 439 0348 / 4392284 / 5442217

Fax: + 91 20 439 0348

Email: adkarve at
pn2.vsnl.net.in<http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org>
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