i hope that this ppt will help to know about bio gas,and how to produce bio gas easily .....

1. Assignment
Topic: Biogas plant
Course Title: Textile Mill Utilities
Course Code: TE-4110
Submitted to:
Araf Al Rafi
Lecturer
Dept. of TE
Daffodil International University
Submitted by:
Md. Monjurul Alam
ID: 141-23-134
Date of Submission: 05 – 04 - 2017

2. Introduction:
Biogas is produced during fermenting or rotting of organic substances in airvoid conditions.
It consists on the average of 50 – 60% methan, 30 – 40% carbon dioxide and small quantities of
remainders.
The technology with biogas has important potentialities within the waste disposal.
Biogas can be yielded from every organic or biologic substrate, that can be disintegrated by
bacterial processes, e.g. manure, sludge, biodegradable waste and leftovers.
The ideal method to yield biogas is the fermenting of biological waste together with other
substances such as sludge or manure.
Biogas is condensed and brought to a granary. Via a supercharger the biogas is conducted to
a power station or to the gas engines producing electricity and utilizable waste heat by
means of a generator.
About 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 digesters.
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.

3. How Is Biogas 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.
About Fixed Dome Type Biogas Plant:
 The various forms of biomass are mixed with an equal quantity of water in the mixing
tank. This forms the slurry.
 The slurry is fed into the digester through the inlet chamber.
 When the digester is partially filled with the slurry, the introduction of slurry is stopped
and the plant is left unused for about two months.
 During these two months, anaerobic bacteria present in the slurry decomposes or
ferments the biomass in the presence of water.
 As a result of anaerobic fermentation, biogas is formed, which starts collecting in the
dome of the digester.
 As more and more biogas starts collecting, the pressure exerted by the biogas forces the
spent slurry into the outlet chamber.
 From the outlet chamber, the spent slurry overflows into the overflow tank.
 The spent slurry is manually removed from the overflow tank and used as manure for
plants.
 The gas valve connected to a system of pipelines is opened when a supply of biogas is
required.

4.  To obtain a continuous supply of biogas, a functioning plant can be fed continuously with
the prepared slurry.
Floating dome type biogas 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:
(i) Constant gas pressure.
(ii) No problem of gas leakage
(iii) Higher gas production
(iv) Scum problem is less

5. Modern Biogas Plant
Biogas plants are decentralized energy system that can lead to self-sufficiency in heat
and power requirements, and at the same time reduces environmental pollution. A biogas
plant stabilizes organic waste through natural biological process in the absence of air and
transforms waste into biogas and biofertilizer. Such facilities are well-suited to wet
organic material and are commonly used for treating biodegradable waste materials such
as waste paper, grass clippings, leftover food, sewage and animal waste. The components
of a modern biogas (or anaerobic digestion) plant includes manure collection, anaerobic
digester, effluent treatment plant, gas storage, and CHP or electricity generating
equipment.
Application of bio gas:

6. 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 (IARI) 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 from it.
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 systems.
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.

7. Advantages of a biogas plant:
1.Dramatically improves the health of users.
2.Rapid fall in diseases like schistosomiasis and tapeworm.
3.Reduces burden on forests and fossil fuel.
4.Produces a clean fuel.
5.Helps in controlling air pollution.
6.Provides nutrient rich manure for plants ( in nitroren and phosphorus).
7.Controls water pollution by decomposing sewage , animal dung and human excreta.
Limitations:
1.The construction costs of biogas plants vary between different countries, they are often high
relative to the income of the farmers and other potential users.
2.Poor farmers are still lacking behind for adopting this technology because:
>Initial cost of installation of the plant is high.
>Number of cattle owned by an average family of farmers is inadequate to feed a biogas plant.
Potential for spread:
In Bangladesh since it is thought 80% of the manure from 22 million cattle in the country could
be made available for biogas production.
It has been calculated that only 19% of biogas potential has been utilized in rural china and
1023 million tones of biogas can be extracted.
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 21st

8. 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.