| Intro to Rice Husk Briquetting |
Utilization of agricultural residues is often difficult due
to their uneven and troublesome characteristics. The process
of compaction of residues into a product of higher density
than the original raw material is known as densification,
briquetting or pelleting. Briquetting has lately aroused a
great deal of interest in developing countries all over the
world as a technique for upgrading of residues as renewable
energy sources.
NAEF saw the technology on tours in Bangladesh. There, nearly
every rice mill has a briquetting machine and local demand
for the briquetted logs is high from both households and restaurants
for cooking. The price of the briquettes is same price as
high quality firewood there, but the users claim that there
is less smoke/higher burning efficiency from the rice husk
briquettes.
In Nepal the technology was introduced in a donor funded
program some 20 years ago through Nepal Academy of Science
and Technology (NAST).
The program imported four whole briquetting factories from
Taiwan, and provided on a loan basis to private companies
along technical and marketing training. All but one company
failed Maihipi Briquette Factory (Shiva Mandir Kawasoti, Nawal
Parasi District Phone: 078 540200). This company has 10 production
lines yet due to low demand runs only two of the lines. Their
market is mostly at 3-5 star hotels in Kathmandu who use in
their,braziers and fireplaces to show their tourists/guests
that they are using renewable sources of energy and not precious
firewood from the mountains. Unfortunately, the costs are
three times higher than high quality firewood and therefore
there is no demand from local people.
Upon seeing the success of RHB in Bangladesh NAEF began developing
its own RHB machine in 2007 and utilizing the Bangladeshi
model will extend the technology to local rice mills that
should reduce the price (by our calculations) to that of firewood
and thereby making this safe renewable energy available to
all the people of Nepal.
Converting residues into a denser forms has the following
advantages.
- The process also helps to reduce deforestation by providing
a substitute for fuel-wood.
- The process increases the net calorific value per unit
volume
- The denser product is easy to transport and store
- The process aids in solving the problem of residue disposal.
- The fuel produced is uniform in size and quality
- Cleaner burning and reduced smoke improves the health
risks to women/kitchen workers.
Links to Rice Husk Briquette resources
Asian Institute
of Technology Manual for Screw-press briquetting machines
and briquette fired stoves
Asian
Institute of Technology A Study on Improved Biomass Briquetting
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