INSTITUTIONAL SIZE RICE HUSK GAS STOVE

Reactor
Engr. Alexis Belonio
Central Philippine University
Iloilo City, Philippines
Good news!
An institutional size rice husk gas
stove technology is already available
for use by restaurants, school canteen,
small scale processing industries,
catering services, and others. Instead
of spending fuel for LPG, a rice hull
fuel gas stove is a good alternative to
reduce fuel cost. Rice husk is
gasified inside the reactor, and the gas
generated is ignited in the burner to
produce luminous bluish flame for
cooking. The stove is very much
convenient to operate compared with
other designs of rice husk stove. The
amount of flame can be finely
controlled during operation.
Gas Pipe
The institutional size rice husk gas stove technology is another development in line with
rice husk gasification project of the Department of Agricultural Engineering and
Environmental Management of the College of Agriculture, Central Philippine University
in Iloilo City, Philippines.
This technology was
developed with the
assistance fromthe group
of undergraduate
agricultural engineering
students Lucio Larano,
Daniel Belonio, Norman
Apote, and April Belasa.
Primary
Burner
Secondary
Burner
Gas Pipe from
Reactor
Chimney
The Institutional Size Rice Husk Gasifier
The Burners Designed for 20-Liter Capacity Pot
The stove as shown
consists of (1) Primary and
Secondary Gas Burners -
where the gas is burned to
produce luminous blue
flame color, (2) Fuel
Reactor - where rice husk is gasified during
operation by burning the fuel with limited
amount of air, (3) Char Chamber – where
burned fuel is discharge fromthe reactor after
gasification, (4) Blower– which supplies the
needed amount of air for gasification,(5) Char
Lever – which discharge burned rice hull after
gasification, (6) Control Switch – which
increase or decrease the flame intensity, (7) Gas
Pipe – which convey the gas generated fromthe
reactor to the burner, and (8) Chimney – which
discharges unwanted gases .
The fuel reactor (40 cmdiameter) can be placed
outside the cooking area while the burner (30
cmdiameter) can be placed inside, for much
cleaner operation. Unwanted gases can be
discharged through a chimney (2 in. φpipe) that
can be extended through the roof.
Firing of Fuel Reactor
Flammable gas, primarily of carbon monoxide
and hydrogen are produced during operation as
the burning fuel moves down the reactor. The
by-product after gasification is a good source of
carbonized rice husk as material for crop
production. .
The stove consumes 14 kilograms of rice husk
per load within 50 to 55 minutes continuous
operation. The energy input for the blower is 22
watts at 220 volt line. The specific gasification
rate is 142 to 145 kg/hr-m
2
while the
combustion zone rate is 2 to 2.5 cm/min. Startup time for rice husk is 1 minute while the time
to produce combustible gases is alsoa minute. Two 10-literofwater can be boiled in the
stove within 18 to 23 minutes. The advantage features of the stove are as follows: (1)
Easy to start with almost no smoke at all, (2) Convenient to operate by using gate valves
and switch knob to control the flame, (3) Clean to operate with no fly ashes, (4) Low
operating cost since it uses rice husk as fuel and minimal amount of electricity, and (5)
the by-product after gasification is a carbonized rice husk (30% of rice husk weight)
which is a good material as soil conditioner.
Bluish Color Flame from the
Burners
The investment cost for the stove is P40,500.00 per unit (two-burner model) and the
computed cost per 6-hour day operation is P117.00 (1 USD = 55 PHP). A savings of
P173,374.32 per year can be realized comparedwith 50-kg LPG large size stove. Three
or more burner models can also be made but of relatively higher in cost.
The technology is now in commercialization stage.Interested organizations to adopt this
technology may contact the Project Director, Appropriate Technology Center,
Department of Agricultural Engineering and Environmental Management, College of
Agriculture Central Philippine University, Iloilo City, Philippines. Telephone number
063-33-3291971 loc 1071, email ad atbelonio@yahoo.com, and mobile phone 063-0916-7115222