There are ways one can
contribute to the environment even as you stand in the kitchen. Rather than
throw the banana peels or spinach stems or other biodegradable waste into the
dustbin, you could toss them into the Compact Biogas Plant to create pollution-free
methane gas and, in effect, help conserve planet earth's depleting fossil fuels.
The significance of this innovation:
"Traditionally,
biogas is produced from dung. Around 40 kg of dung needs to be fermented for 40
days to produce 250 grams of methane. Due to this highly inefficient process,
biogas has not emerged as an alternative to LPG. However, this system requires just
1 kg of sugar or equivalent in biodegradable substance to be fermented for 24
hours, to produce the same amount of methane." It is this efficiency and
uniqueness, as compared to other biogas projects.
1CuM Digestor
CARE Biodigestor
Tremendous Acceptance
The CBP has found
tremendous acceptance. Currently, the plant system has been installed in 20000
households in rural as well as urban Maharashtra and in
surrounding areas. This is a conservative figure.
TheThane Municipal
Corporation has installed a 20,000-litre plant. "They use the feedstock
from a nearby restaurant. The Thane Municipal Corporation is looking at
increasing the capacity of the plant by four times. Incidentally, the
Thane Municipal Corporation CBP produces 1.83 lakh kg of methane gas per annum,
which otherwise would have cost the civic body Rs 76.5 lakh annually to
generate. The methane is used for various heating applications such as those in
use at hospitals and crematoria, and has resulted in a reduction in the use of
diesel.
While
the CBP is more
suitable to farmers (for whom installation space and biodegradable materials,
such as farm waste, are easily available), city households and, more
appropriately, bungalow residents can also avail of the device.
Kit Model for Schools
How
it works ?
The plant is installed in an open area close to the
house. The
device has several pipes through which feedstock is added to the approximately
6 ft X 6 ft fermentor; digested residue is removed and the generated blue
methane biogas travels into the kitchen to a special burner.
Biogas is not really a substitute for LPG, but is
a standby and can
be used alongside LPG. Installation costs at Rs 9,000 for a 1,000-litre
fermentor (compared to Rs 5, 000 for an LPG cylinder with a two-burner range)
may seem steep, but the kitchen budget does eventually get a breather.
The per-day running cost of a CBP fed on waste flour
would come to
around Rs 2, compared to the Rs 30 a day equivalent usage in terms of LPG.
In addition to the benefits in terms of environment
and household
budgets, the CBP can be a life-saving device for those who use indoor
biogas choolas (stoves). According to the World Health
Organisation, about three million people die every year due to exposure to
suspended particle matter in the air, and 85 per cent of those deaths are due
to indoor air pollution.
"Indoor pollution is caused mainly due to traditional
cooking
stoves, using traditional biomass- So why has this biogas plant
created a stir in international scientific circles and aroused curiosity
amongst people? The conventional biogas plant works on human or animal excreta.
To produce 250 gms of methane, you require 40 kgs of excreta. It takes 40 days
for this to decompose. In sharp contrast, this innovative 'new compact biogas
technology' method requires 1 kg of starch or sugar (in the form of vegetable
waste, flour collected from the floor of a flour mill) and just 24 hours to
produce 250 gms of methane gas.
copyright 2007 @ Centre for Application
of Renewable Energy
