JAWAHAR NAVODAYA

VIDYALAYA
PAIKMAL,

BARGARH(O)
INVESTIGATORY PROJECT OF BIOLOGY ON
BIOGAS PLANT
2024-25

PREPARED BY :- AYUSH TANDI

Roll no.:-
Guided by:-

S.K.MISHRA sir
Certificate
This is to certify that Ayush Tandi of
class XII has completed her BIOLOGY
project titled BIOGAS PLANT under the
guidance of Mr.S.K. Mishra for the
academic year 2024-25. The certified
student has been dedicated throughout
his research and completed his work
before the given deadline without
missing any important details from the
project. It is also certified that this
project is the individual work of the
student and can be submitted for
evaluation.

Sign of external.
Sign of teacher.
Sign of principal
Acknowledgeme
nt
Primarily i would thank god for being to complete this
project with success. Then I would like to thank my
Biology teacher Mr.S.K. MISHRA whose valuable guidance
has been the once that helped me patch this project and
make it “full proof” success his suggestions and his
instructions has served as the major contributor towards
the completion of the project.

Then I would like to thank my parents and friends who

have helped me their valuable suggestions and guidance
has been helpful in various phrases of the completion of
the project.

Last but not the least I would like to thank my classmates

who have helped me a lot.
 Contents
 BIOGAS
 BIOGAS PLANT
 BIOGAS GENERATION SYSTEM
 TEMPERATURE
 METHANOGENS
 TYPES OF BIOGAS PLANT.
 RAW MATERIAL FOR BIOGAS PRODUCTION
 QUALITY OF BIOGAS
 APPLICATION OF BIOGAS
 BIOGAS AND RURAL PEOPLE
 ECONOMICS
 SCOPE OF TECHNOLOGY
 PROBLEMS FACED
 RECOMMENDATION
 CONCLUSION
 BIBLIOGRAPHY
INTRODUCTION
This project is based on biogas, which is increasingly used
as an alternative source of energy, in today’s world where
there is crisis for energy. Human civilisation has been
using energy in different form from the very first day of
their existence. Most of this energy comes from fossil
fuels, which supply nearly 75% of the world’s energy. The
abundant, cheap energy provided by fossil fuels has
made it possible for humans to exploit a staggering
variety of resources, effectively expanding their resource
base. In particular, the development of mechanized
agriculture has allowed relatively few farmers to work
vast tracts of land, producing an abundance of food and
making possible a wild growth of population. But fossil
fuels are being depleted a hundred thousand times faster
than they are being formed. At current rates of
consumption, known reserves of Petroleum will be gone in
about thirty-five years: natural gas in fifty-two years: and
coal in some two hundred years. Hence there is a need to
look for alternative sources of energy including in rural
areas of INDIA where majority people live. BIOGAS PLANT
is one of the alternatives which are efficient, cost
effective and hygienic. This project tells about the
construction, working, cost, advantages and demand of
biogas in coming decades.
Biogas plant

What is biogas?
 Biogas is a flammable gas that accrues from
the fermentation of biomass in biogas plants.
Biogas typically refers to a gas produced by the
biological breakdown of organic matter in the
absence of oxygen. Biogas originates from
biogenic material and is a type of biofuel.
 Biogas is a renewable source of energy.
 Biogas comprises primarily methane (CH4) and
carbon dioxide (CO₂) and may have small
amounts of hydrogen sulphide (H₂S), moisture
and siloxanes.
 The gases methane, hydrogen, and carbon
monoxide (CO) can be combusted or oxidized
with oxygen. Biogas can be used as a fuel in
any country for any heating purpose, such as
cooking. It can also be used in anaerobic
digesters where it is typically used in a gas
engine to convert the energy in the gas into
electricity and heat. Biogas can be
compressed, much like natural gas, and used
to power motor vehicles.
Diagram of a typical plant
How biogas is generated?
 Biogas is practically produced as landfill gas (LFG) or
digester gas. Biogas can be produced using anaerobic
digesters. These plants can be fed with energy crops such as
maize silage or biodegradable wastes including sewage
sludge and food waste. During the process, an air-tight tank
transforms biomass waste into methane producing
renewable energy
 Landfill gas is produced by wet organic waste decomposing
under anaerobic conditions in a landfill. The waste is covered
and mechanically compressed by the weight of the material
that is deposited from above. This material prevents oxygen
exposure thus allowing anaerobic microbes to thrive. The gas
builds up.

What is biogas plant?

A biogas plant is the name often given to an anaerobic digester
that treats farm wastes or energy crops. Biogas can be produced
using anaerobic digester
A biogas plant consists of the following things-
Concrete tank (digester) – The bio wastes are collected here.
Floating cover- It is placed over the tank and it keeps on rising as
the gas keeps on increasing in the tank.
An outlet-The outlet is connected to a pipe through which the
gas is collected and further used.
Slurry collector- Here cow dung is added which contains
bacteria methanogens, which is present in the rumen part of the
stomach of cattle, that act on the bio wastes and produce
methane gas.
Sludge collector- The spent slurry is removed through this and
can be used as fertilizer or various purposes.

Steps in biogas generation-

There are four key biological and chemical stages of anaerobic
Digestion:
(i)Hydrolysis
(ii) Acidogenesis
(iii) Acetogenesis
(iv) Methanogenesis

 HYDROLYSIS-In most cases, biomass is made up of large

organic polymers. For the bacteria in anaerobic digesters to
access the energy potential of the material, these chains
must first be broken down into their smaller constituent
parts. These constituent parts, or monomers, such as sugars,
are readily available to other bacteria. The process of
breaking these chains and dissolving the smaller molecules
into solution is called hydrolysis. Therefore, hydrolysis of
these high-molecular-weight polymeric components is the
necessary first step in anaerobic digestion. Through
hydrolysis the complex organic molecules are broken down
into simple sugars, amino acids, and fatty acids. Acetate and
hydrogen produced in the first stages can be used directly by
methanogens. Other molecules, such as volatile fatty acids
(VFAs) with a chain length greater than that of acetate must
 first be catabolised into compounds that can be directly used
by Methanogens.
 ACIDOGENESIS-The biological process of Acidogenesis
results in further breakdown of the remaining components by
acidogenic (fermentative) bacteria. Here, VFAs are created,
along with ammonia, carbon dioxide, and hydrogen sulphide,
as well as other by-products. The process of Acidogenesis is
similar to the way milk sours.
 ACETOGENESIS-The third stage of anaerobic digestion is
Acetogenesis, Here, simple molecules created through the
acidogenesis phase are further digested by acetogens to
produce largely acetic acid, as well as carbon dioxide and
hydrogen.
 METHANOGENESIS-The terminal stage of anaerobic
digestion is the biological process of Methanogenesis. Here,
Methanogens use the intermediate products of the preceding
stages and convert them into methane, carbon dioxide, and
water. These components make up the majority of the biogas
emitted from the system. Methanogenesis is sensitive to
both high and low pH and occurs between pH 6.5 and pH 8.
The remaining, indigestible material the microbes cannot use
and any dead bacterial remains constitute the digestate.

Temperature
The two conventional operational temperature levels for
anaerobic digesters are determined by the species methanogens
in the digesters:
 Mesophilic digestion takes place optimally around 30 to 38
°C. Or at ambient temperatures between 20 and 45 °C,
where Mesophiles are the primary microorganism present.
 Thermophilic digestion takes place optimally around 49 to 57
°C, or at elevated temperatures up to 70 °C, where
thermophiles are the primary microorganisms present.
Methanogens
Methanogens are microorganisms that produce methane as a
metabolic by-product in anoxic conditions. They are classified as
archaea, a group quite distinct from bacteria. They are common in
wetlands, where they are responsible for marsh gas, and in the
guts of animals such as ruminants and humans, where they are
responsible for the methane content of belching in ruminants and
flatulence in humans. Methanogens are usually coccoid
(spherical) or bacilli (rod shaped). There are over 50 described
species of methanogens, which do not form a monophyletic
group, although all methanogens belong to Archaea.
Methanogens are anaerobic organisms and cannot function under
aerobic conditions. They are very sensitive to the presence of
oxygen even at trace level. Usually, they cannot sustain oxygen
stresses for a prolonged time.

Types of biogas plant

Classification of biogas plants depends upon the plants design
and mode of working-
 Movable types drums plant
 Continuous type plant
 Batch type plant
Batch type biogas plant-Batch type biogas plants are
appropriate where daily supplies of raw waste materials are
difficult to be obtained. A batch loaded digester is filled to
capacity sealed and given sufficient retention time in the digester.
After completion of the digestion, the residue is emptied and filled
again. Gas production is uneven because bacterial digestion
starts slowly, peaks and then tapers off with growing consumption
of volatile solids. Connecting batch loaded digester in series and
fed at different times so that adequate biogas is available for daily
use.

The salient features of batch-fed type biogas plants are:

(i) Gas production in batch type is uneven.
(ii) Batch type plants may have several digesters for
continuous supply of gas occupying more space.
(iii) This type of plants require large volume of digester,
therefore, initial cost becomes high.
(iv) This plant needs addition of fermented slurry to start the
digestion process.
Continuous type biogas plant-
In continuous type biogas plant, the supply of the gas is
continuous and the digester is fed with biomass regularly.
Continuous biogas plants may be single stage, double stage or
multiple stages. Digestion of waste materials in a single chamber
or digester is called single stage process, in two chambers or
digester is called multi stage process. In double stage process,
acidogenic and methanogenic stage are physically separated into
two chambers. These plants are economic, simple and easy to
operate. These plants are generally for small and medium size
biogas plants.

The important features of continuous type biogas plants are:

 Gas production is continuous.
 Retention period is less
 Less problems as compared to batch type.
 Small digestion chambers are required
MOVABLE DRUM TYPE PLANTS-
This also known as floating dome type biogas plants. The
conventional movable drum type comprises a masonry digester
with an inlet on one side for feeding slurry and an outlet on the
other side for removing digested slurry. The gas collects in a steel
gasholder which is inverted over the slurry and moves up and
down depending upon accumulation and discharge of gas guided
by a central guide pipe. This movable gas holder is made of steel.
Advantages:
 Constant gas pressure.
 No problem of gas leakage
 Higher gas production
 Scum problem is less
 Floating gas-holder type bio-gas plant.

RAW MATERIAL FOR BIOGAS

PRODUCTION-
Agricultural residues from both the agricultural and agro- industry
abound and are usually treated as waste materials and not as a
potential resource. Biomass is any material originating from living
organisms consisting of carbon and hydrogen that can be
combusted or burned. Agricultural wasted such as manure and
faeces also is biomass and can be harnessed to generate ethane
gas, a useful gas that can be used for energy production.
Biogas can be produce from mixtures of cattle slurry and pressed
sugar cane stalk, with and without urea.

Sources Raw materials

Crop waste Sugar cane trash, weeds, crop
stubble, straw, spoiled fodder,
haulms and tops, silage liquor
Animal waste Excreta and urine from man and
domesticated animals,
slaughterhouse wastes, fishery
wastes, tannery wastes, wool
wastes.
Municipal waste Sewage, kitchen wastes,
domestic refuse.
Agro industrial waste Oil cakes, sugar cane bagasse,
rice bran, tobacco wastes, fruit
and vegetable processing
wastes, sisal pulp, tea wastes,
coffee pulp, textile wastes,
brewery and distillery wastes,
sawdust.
Quality of biogas
Every day, BIOGAS used for power generation and heat transfer
robs the client of valuable dollars due to the improper treatment
of gas. Crude BIOGAS, like crude oil, cannot be used as a fuel
without at least some minimal form of environment.
Each BIOGAS has its own “Signature”.
 Methane Gas Content.
 Non-Methane Gas Fraction.
 Moisture Content.
 Sulphur Species Content.
 Volatile Organic Contaminants

WHAT ARE SILOXANES?

Siloxanes are organosilicons added to many personal care
products and are present in almost all biogas. These siloxanes are
formed from the anaerobic decomposition of materials commonly
found in soaps and detergents.
Typical levels are of siloxanes:
 Landfills-0.5 to 50 ppm v/v.
 Digesters-0.5 to 140 ppm v/v.
During combustion of biogas containing siloxanes, silicon is
released and can combine with free oxygen or various other
elements in the combustion gas. Deposits are formed containing
mostly silica (SiO₂) or silicates (Si.O.) and can also contain
calcium, sulphur, zinc, phosphorus. Such white mineral deposits
accumulate to a surface thickness of several millimetres and must
be removed by chemical or mechanical means. Carbon Dioxide,
Nitrogen, and Oxygen-containing organics also cause problems.
Water, hydrogen sulphide, and halogens also play a role
depending on the end use of the gas. Practical and cost-effective
technologies to remove siloxanes and other biogas contaminants
are currently available.

APPLICATION OF BIOGAS
Biogas is a renewable source of energy. Since it is cleaner
and greener and friendly it is used for a variety of
purposes
 Biogas production units provide a decentralized fuel
supply and waste management system, both of
which are becoming increasingly attractive,
particularly in rural areas of developing countries.
 The enormous potential of biogas, estimated at
17,000 MW. The capacity was derived principally
from estimated agricultural residues and dung from
India’s 300 million cattle. Biogas technology may
have the potential to short- circuit the ‘energy
transition’ and is described from biomass to ‘modern’
fuels.
 With the bourgeoning population in metro cities and
growth of urban centres, the enormity of waste
generated is proving to be a huge task for disposal
by city municipal authorities. Therefore, this process,
driven further can turn out to be best boon in waste
management.
 The scope for saving huge funds used for
transporting the waste as at present is
immeasurable. Also the search and location for land-
fills and promotion of pollution in areas nearer to
urban centres can be avoided.
  The gas is useful as a fuel substitute for firewood,
dung, agricultural residues, petrol, diesel, and
electricity, depending on the nature of the task, and
local supply conditions and constraints, thus
supplying energy for cooking and lighting.

 Biogas systems also provide a residue organic waste,

after anaerobic digestion that has superior nutrient
qualities over the usual organic fertilizer, cattle dung,
as it is in than aerobic digesters also function as a
waste disposal system, particularly for human waste,
and can, therefore, prevent potential sources of
environmental contamination and the spread of
pathogens
 Apart from the direct benefits gleaned from biogas
systems, there is other, perhaps less tangible
benefits associated with this renewable technology.
By providing an alternative source of fuel, biogas can
replace the traditional biomass based fuels, notably
wood. Introduced on a significant scale, biogas may
reduce the dependence on wood from forests, and
create a vacuum in the market, at least for firewood
(whether this might reduce pressure on forests
however, is contestable).
 Can be used as alternate power-generation to lift
water for farming purpose, house-hold, street
lighting.

BIOGAS AND RURAL PEOPLE

Biogas technology is a particularly useful system in the
Indian rural economy, and can fulfil several end uses. The
Indian Agricultural Research Institute (JARI) and Khadi and
Village Industries Commission (KVIC) introduce biogas
technology in rural India. It is known as "gobar gas" in
rural India. Due to huge availability of cow dung in rural
areas it is growing as a huge source of energy. Due to less
cost of biogas plant it can set up in every household and
the people get various benefits

1. PERSONEL USE
 The people get manure and gas for their personal use like
lighting and cooking
 Child education improves as they are no longer needed in
collection and process of fire wood and the mother can spare
time on child education
 Soil fertility increases as the humus in the form of organic
fertilizer is applied and replaces the chemical fertilizers.
 Women empowerment is seen as she generates income
equalling the family income per year.
2. INDUSTRIES-Small-scale industries are also made possible,
from the sale of surplus gas to the provision of power for a
rural-based industry; therefore, biogas may also provide the
user with income generating opportunities. The gas can also
be used to power engines, in a dual fuel mix with petrol and
diesel, and can aid in pumped irrigation system
3. WASTE MANAGEMENT- At village level, Taluk and District
levels, the waste management is effectively carried out by
optimum utilization of bio-waste for producing bio- gas. In
addition, the spending by local self-governments is
drastically cut down by using the Bio-waste for producing
bio-gas and thereby contributes for better environment.
 4. INCOME & EMPLOYMENT GENERATION- By introducing
the digesters at individual households, ample employment is
generated for villagers, income by way of sale of bio-gas,
sale of residuals etc.

ECONOMICS
Biogas plant can be set up at individual level also. It is within the
range of farmer family. However setting up of big biogas plant
takes about 5 lakh which can be regained within few years by
selling of the gas generated. Raw materials are also easily
available and priceless.

SCOPE OF THE TECHNOLOGY:

Enriched biogas is made moisture free by passing it through
filters, after which it is compressed up to 200 bar pressure using a
three stage gas compressor. Compressed gas is stored in high
pressure steel cylinders as used for CNG. There is large potential
of this technology in buses, tractors, cars, auto rickshaws,
irrigation pump sets and in rural industries. This will help to meet
energy demand for rural masses thus reducing burden of
petroleum demand, moving towards energy security and will
improve economic status by creating employment generation in
rural area.

PROBLEMS FACED IN INDIA

 Many people and farmers are not aware of the technology
and thus cannot obtain optimum utilisation
 Lack of sufficient feedstock: India has a shortage of
suitable feedstock for biogas production, such as
agricultural waste and sewage, which limits the potential
for CBG production.
  Limited technology and infrastructure: India have a limited
number of biogas plants and the technology used in these
plants is often outdated, which makes it difficult to
achieve large-scale CBG production.
 High costs: The cost of building and operating biogas
plants in India is relatively high, which makes it difficult for
small and medium-sized farmers to participate in CBG
production.
 Conventional Technology--It is common for several
compressed biogas plants in India to function using
conventional technology, which is not up to the mark and
directly limits the possibility of scaling CBG production.

CONCLUSION

With the increasing demand of energy biogas

demand has also increased. Many biogas
plants have been set up in the rural and urban
area by the municipality. Biogas will soon
replace fossil fuels as a source of energy. With
this global warming and greenhouse effect
will also reduce in the coming years. As we
head into the 21 century, awareness and
education will most assuredly continue to be
the most important ways to spread use of
biogas.
The developed countries are coming up with
new technologies to make better biogas plant
to meet the increasing demand. This project
will help the people to contribute towards the
biogas plant and understand it as a better
source of energy. In short, with the coming
technology the energy scenario will be
changed in the coming years.
Bibliograp
hy
 WIKIPEDIA
 BOOKS ON BIOMAS PLANT
 GOOGLE
 NCERT BOOK CLASS XII
CBSE.
 NEWSPAPER