A biogas plant is a facility that produces biogas, a renewable energy source, through the anaerobic digestion of organic materials. Anaerobic digestion is a biological process that breaks down organic matter in the absence of oxygen, producing biogas as a byproduct. Biogas primarily consists of methane (CH4) and carbon dioxide (CO2), along with small amounts of other gases.

1. BIOGAS PLANT

2. Biogas plant
 Biogas plant is an airtight container that facilitates
fermentation of material under anaerobic condition
 Anaerobic digestion of organic matter producesa mixyure of
methane (CH4) and carbon dioxide (CO2) gas.
 The material which is used in biogas plant for producing
biogas called Biomass.
 Forms of biomass listed below may be used along with water
 Animal dung, Poultry waste, Plant wastes, human excreta,
Industrial waste , Domestic waste.

3. Properties of Biogas
 Biogas is a mixture of different components and the
composition varies depending upon the characteristics of
feed materials, amount of degradation, etc.
 Biogas predominantly consists of 50 to 70 per cent methane,
30 to 40 per cent carbon dioxide and low amount of other
gases. Methane is a combustible gas.
 The energy content of biogas depends on the amount of
methane it contains. Methane content varies from about 50
percent to 70 percent.

4. Biogas composition
 Methane CH4 : 55-70%
 Carbon dioxide CO2 : 25-40%
 Nitrogen N2 :0-2%
 Hydrogen Sulphide H2S :0-3%
 Hydrogen H2 :0-2%
 Oxygen O2 :0-2%

6. Components Of Biogas Plant
 Digester or fermentation chamber
 Gas holder or gas storage chamber
 Inlet (pipe or tank)
 Outlet (pipe or tank)
 Mixing tank
 Gas outlet pipe
 Inlet and outlet displacement chambers
 Plant dome or arched roof
 Inlet and outlet gates
 Manhole or digester cover

8. Factors affecting the biogas
production
1. pH (6.5 – 7.5)
2. C:N ratio (30:1)
3. Temperature (30-35 °C)
4. Loading rate
5. Size of the material used
6. Retention time (30-55 days)
7. Seeding
8. Uniform feeding
9. Diameter to depth ratio (0.66:1)
10. Water to input material mixing ratio (1:1)
11. Total solid content of the feed materials (8-10 %)
12. Nutrients
13. Type of feed stocks
14. Effect of Toxic substances
15. Proper mixing/stirring of content in the digester

9. Microbiology of biogas production
 The production of biogas from organic material under
anaerobic condition involves sequence of microbial reactions.
 During the process complex organic molecule present in the
biomass are broken down to sugar, alcohols, pesticides and
amino acids by acid producing bacteria.
 The resultant products are then used to produce methane by
another category of bacteria.
 The biogas production process involves three stages namely:
i. Hydrolysis
ii. Acid formation and
iii. Methane formation

10. Classification
Biogas Plant
Community biogas plants Institutional biogas plants Family size biogas plants
This type of biogas
plants are installed at
individual family
level. The biogas from
this type of biogas
plants are used by the
individual family. The
size of these plants is
recommended up to 6
m3 per day.
These types of biogas
plants are installed by an
institution such as religious
institution like
Gurudwara/Mandir/Gowshal
a or educational institution
like School/College. The
biogas produced from these
plants is used for the
respective institution. The
size of these plants is
recommended also to be
more than 15 m3 per day.
It is a plant to be used by a
group of people as a
community. These types of
plants are installed by a
Village Panchayat/Municipal
Committee for any
Village/Mohalla/Town/City.
The biogas produced from
this type of plant is
distributed to the people
living in that locality. The size
of theses plants is
recommended to be more
than 15 m3 per day.

11. Conventional models
There are two basic models of biogas plants popular in India:
1. Floating-drum type model biogas plants - KVIC model
2. Fixed-dome type model biogas plants - Janta Model Biogas
Plants , Deenbandhu Model Biogas Plants

16. Advantages of biogas Disadvantages of biogas
 Biogas is eco-friendly.
 Provide employment by
biogas plant.
 Biogas generation
produces organic fertilizer.
 It is simple and low cost
technology.
 It reduce greenhouse effect
 . Biogas is not attractive in
large scale.
 Few technology
advancement
 Contains impurity
 Less suitable for
dense metropolitan

17. Reference
 https://slideplayer.com/slide/17101653/
 https://www.homebiogas.com/blog/what-is-a-biogas-plant-
and-how-does-it-
work/#:~:text=A%20biogas%20plant%20is%20a%20facility
%20that%20provides%20oxygen%2Dfree,positive%20effect
s%20on%20the%20environment.
 http://ecoursesonline.iasri.res.in/mod/page/view.php?id=143
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