1. Bio-gas plant
.Introduction:
. Biogas is formed by the natural degradation of organic
matter under anaerobic conditions.
.Microbially controlled production of biogas is an
important part of the global carbon cycle.
.Every year 590-800 million tons of methane are
released into the atmosphere.
.Biogas contains 50-70% methane and 30% carbon
dioxide.
2. .Methane has a calorific value of 21-24Mj/m3 or
around
6KW/m3.
.Biogas is often used for cooking, heating, lighting or
electricity generation.
.Biogas is produced in three steps :
>Hydrolysis: where enzymes degrade complex
carbohyderates , proteins and lipids into their
constituent units.
3. >Acidogenesis: where hydrolysis products are
converted to acetic acid, hydrogen and carbon
dioxide.
>Methanogegesis: where obligate anaerobic bacteria
control methane production from acidogenesis
products.
.Sludge produced from the anaerobic digestion of
liquid biomass is often used as a fertilizer.
.Biogas technologies have been failures in many
developing countries.
4. History:
.Biogas was used for heating bath water in Assyria as
long as 10 th century B.C.
.Well documented attempts to harness biogas dates
from mid 19th century in New-Zealand and India.
.In 2007 , the no of biogas plants in china was 26.5
million.
.In 1999, the no of biogas plants in india was 3 million.
5. .The national project on biogas development has run
since 1981-1982 and promotes its own digester
designs.
.Subsidies from state govt and central govt to install
house
hold bioreactors ranged from 30% to 100% in the
1980’s -1990’s.
6. .Design And Working:
.The two types of biogas plants in usage for biogas
production are:
.>the fixed dome type of biogas plant.
.>the floating gas holder type biogas plant.
8. .Raw materials required for a biogas plant:
>Animal dung.
>Poultry wastes.
>Plant wastes(Husk, grass, weeds)etc.
>Human excreta.
>Industrial wastes(saw dust,food processing wastes).
>Domestic wastes(vegetable peels,waste food) etc.
9. .Principle:
.Biogas is produced as a result of anaerobic
fermentation of biomass in the presence of water.
.Fixed dome type biogas plants are much more
commonly found than Floating gas holder type biogas
plant because:
>requires only locally and easily available materials for
construction.
>inexpensive and easy to construct.
10. .Advantages of a biogas plant:
.Dramatically improves the health of users.
.Rapid fall in diseases like schistosomiasis and
tapeworm.
.Reduces burden on forests and fossil fuel.
.Produces a clean fuel-
.Helps in controlling air pollution.
11. .Provides nutrient rich manure for plants ( in nitroren
and phosphorus).
.Controls water pollution by decomposing sewage ,
animal dung and human excreta.
12. .Limitations:
.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.
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.
13. .Advantages of biogas as a fuel:
>High calorific value.
>Clean fuel.
>No residue produced.
>No smoke produced.
>Non Polluting.
>Economical.
14. >Can be supplied through pipe lines.
>Burns readily-has a convenient ignition temperature.
15. .Potential for spread :
.Even in those countries with an established record in
installing small scale biogas plants, there remains
potential for continued spread of these systems.
.The potential maximum number of household
livestock digesters in india has been estimated as 12-
17 million, based on the availability of cow manure,
compared to the current levels of around 4 million.
16. .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.
17. .Conclusions:
.Biogas technology offers a vast set of benefits.
.Except India and China, in other developing countries,
the proportion of functional plants is often 50% or
less.
.Considerable govt. involvement is requested for these
support networks to be continued over time.
.Its a challenge to develop designs of biogas plants
which
18. Deliver lower cost, improved robustness,
functionality, ease of construction, operation and
maintenance would aid the market penetration of
biogas plants.
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Roll no: a12
Sec:e3203
Name : Jahanzaib bhat.
