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DESIGNANDCONSTRUCTIONOFBIOGASDIGESTER

Presented by:

T.Rohit Kumar (09881A0220)

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WHATISBIOGAS?

Its a mixture containing

50-70% methane

30-40% carbon dioxide

Its a gaseous fuel used for cooking andproducing electricity.

Biogas is produced by the breakdown of organicwaste by bacteria without oxygen (anaerobicdigestion or fermentation).

CH4

CO2

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What Type of Waste Produces Biogas?

Any organic waste can produce biogas

Human, animal, fruit and vegetable waste

What Type of Waste Does NOT Produces Biogas?

Fiber rich waste such as wood, leaves, etc. aredifficult to digest.

Heavy metal Inorganic materials in high concentration

(Nitrate, Sodium,Potassium,Calcium,Magnesiumetc)

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WHATISABIOGASDIGESTER?

A device in which biogas is produced fromanaerobic decay(decay that occur without oxygen).

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ANAEROBIC DIGESTIONINA BIODIGESTER

Digester is fed with a mixture of

water and waste called a slurry

First of all, the slurry containingcomplex compounds is brokendown to digestible organic matter

by Hydrolysis.

Digestible organic matter isbroken down by acid-producingbacteria

By-products are then broken downby methane-producing bacteria toCH4 and CO2.

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CLASSIFICATIONOFBIOGASPLANTS

Biogas plants are mainly classified as:

Floating-drum biogas plant

Fixed-dome biogas plant

Balloon biogas plant

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FLOATING-DRUMBIOGASPLANT

Consists of two main parts

Digester

Gas collector

Digested well is divided into

compartments. Two pipes, one serves as inlet

and other as outlet.

Gasholder is cylindrical drumin shape with conical top.

Gas holder is made up of mildsteel.

Most expensive component ofthe plant.

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FIXED-DOMEBIOGASPLANT

Working is same asfloating-drum plant.

It has Dome-shapeddigester.

Floating drum is replacedby fixed dome roof.

Gas holder and digesterare combined.

Gas stored in upper partof the digester.

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ADVANTAGESAND DISADVANTAGESOFFLOATINGDRUMPLANT

Advantages:

Simple and easily understood operation

Constant gas pressure

Higher gas production

Volume of the gas stored is visible from the position ofgas holder

Disadvantages:

Rusting and cost of the gas holder are the main

drawbacks of this plant Life span of the plant is less due to corrosion

Frequent painting of Gas holder is required

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ADVANTAGESAND DISADVANTAGESOFFIXED-DOMEPLANT

Advantages:

Simple in construction

Low cost compare to Floating-drum plant

Heat insulation is better

No maintenance

Life span of the plant is more

Disadvantages:

Not easy to build

Labor-sensitive

Variable gas pressure

Poorly constructed roof generally leads to gas leakagefrom top.

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CONCLUSION

It creates source of fuel for cooking.

Provide a fertilizer.

Leads to improvement in the environment, and

sanitation and hygiene. Biogas plants significantly lower the greenhouse

effects on the earths atmosphere.

As India is agro-based country ,biogas can be

produced in large scale.