generations there will be demand for excessive energy because of fast depletion
of fossil fuel deposits, fuel quality, price which is to be paid for basic
materials plus their transportation cost and all the above have degradation of
environment which is caused by the use of conventional energy sources. The
solution lies by the use of non-conventional energy or renewable resources
(Muthu, D 2017). The worldwide construction of
new biogas plants will continue in the next 10 years Between 2016 and 2025, the
installed capacity will increase from around 7,000 MWel to 9,600 MWel, while
the number of biogas plants will grow from circa 12,000 to 15,000 (Smith, Sarah
2016). The fact that biogas is not new but to modern days it is the effective
renewable energy. Society can also build their own biogas power plant, its
called biogas digester, before we go to how to make biogas digester lets learn
how does biogas ocured.
is a biofuel produced from the anaerobic fermentation of carbohydrates in plant
material or waste (eg food peelings or manure) by bacteria. Biogas is characterized
based on its chemical composition and the physical characteristics which result
from it. It is primarily a mixture of methane (CH4) and inert carbonic gas
(CO2). However the name “biogas” gathers a large variety of gases resulting
from specific treatment processes, starting from various organic waste –
industries, animal or domestic origin waste etc
Different sources of production lead
to different specific compositions. The presence of H2S, of CO2 and water make
biogas very corrosive and require the use of adapted materials. The composition
of a gas issued from a digester depends on the substrate, of its organic matter
load, and the feeding rate of the digester.It is mainly composed of methane, with some carbon dioxide and
other trace gases. However, the proportion of methane within the biogas can
vary between 50% and 80%, depending on whether some oxygen is able to enter at
the beginning or during the process. If some oxygen is present, the bacteria
will respire aerobically and will produce
a gas with a higher proportion of carbon dioxide and a lower proportion of
methane (BBC UK 2000).
The optimum temperature for biogas production is between 32oC
and 35oC. Temperatures above and below this optimum can result in
less biogas being produced, which can be a problem in hotter and cooler
countries (see table below) (BBC UK 2000).
Cooler country (ex. UK)
Temperatures below optimum slow
the respiration rate of bacteria resulting in slower biogas production.
Bury the biogas generator or build
the biogas generator with thick walls to insulate the generator and keep the inside warmer.
Hotter country (ex. India)
Temperatures above optimum begin
to denature bacterial enzymes, resulting in slower biogas production.
Bury the biogas generator in the
ground. The ground helps to insulate the biogas generator to keep it cool
during the day and warm at night.
Now we know that biogas main problem should be
temperatures, that’s why biogas built underground to get fixed temperature
without external factors affect it.
How does the digester works?
Collect the waste or cow dung and mix it with mixture
of anaerobi bacteria with water in the influent channel.
Quickly release the mixture into the influent channel
that lead to the main chamber.
There the anaerobic digestion will occur.
In few days after the digestion, the methane gas that
turn into biogas will rise on top of the dome and escape through the biogas
outlet, where lead to the kitchen to use as cooking gas.
After the mixture is being used, it will turn into a
sludge sediment. The sludge rise up to the effluent channel with help of a pump
to empty the dome
The escape sludge can be use again as a compost to
(SciTech, Youtube 2013)