A biogas plant is defined as a defined construction where biogas
is produced.Biogas is a mixture of gas, it is produced when organic
compounds are fermented and utilised by organisms under anaerobic
condition.
There are different types of digesters present,
- Floating drum plant
- Fixed dome plant
- Tubular plant
- Plastic container plant
- Balloon plant
Fixed dome biogas plant:
Construction and working:
It is one of the digester biogas plant for biogas production.It
has constructed with the following components
1.Digester
2.Mixing tank with inlet pipe
3.Compensating Tank
4.Removal tank
5. Gasholder
6. Gaspipe
7. Supernatant scum and sludge collector
- A fixed-dome biogas plant is constructed underground inorder to
avoid physical damage.
- It consists of a dome shaped fully closed digester.Then the
digester has a fixed, non-movable gas space.
- Size of the digester should be 20 m³.
- When the organic matter are digested by the microbes it
releases out gas.
- So, When gas started to produce and increases with respect to
digestion,the pressure inside the digester also increases.So the
slurry is dispersed into the upper compensation tank or
displacement pit.
- When sufficient amount of gas is produced it is extracted out
from the digester.
- At the same time equal amount of slurry is feed back into the
digester.
- Generally fixed dome plant have fluctuating pressure, so to
maintain constant pressure a special pressure controller and gas
holder is constructed along with the digester.
- Unwanted wastes and stones are collected as scum in the scum
collector.
Advantages:
- Initial cost is low.
- As the digester is fixed no damage occurs and as some parts are
made of steel no rusting.
- Long life span.
- The digester is well insulated.
Disadvantages:
- High technical skills required for operating the digester.
- leakage of gas occurs frequently.
- Gas pressure fluctuation occurs that complicates utilization of
gas.
Hope this helps you:)