Gobar Gas Plant construction Gobar Gas Plant construction

Charisma and Andrea

Bio gas for village…Bio gas for village…

Bio gas is a clean unpolluted and cheap source of energy in rural areas.  It consists of 55-70% methane  which is inflammable. Bio gas is produced from cattle dung in a bio gas plant commonly known as gobar gas plant through a process called digestion. 

Objectives Objectives

1. To provide fuel for cooking purposes and organic manure to rural house holds through family type Bio Gas Plants.2. To mitigate drudgery of rural women, reduce pressure on forests and accentuate social benefits. 3. To improve sanitation in villages by linking sanitary toilets with bio gas plants.

Construction Technique – Need to Construction Technique – Need to keep in Mind keep in Mind Site SelectionDigging of the pitFoundation laying Machinery construction workLaying of pipeline and accessoriesPrecautions in lying pipelines.

A lay out Model of Gobar gas plantA lay out Model of Gobar gas plant

Components required for Bio gas Components required for Bio gas plantplant Mixing tank and inlet  Digester Gas holder or gas storage dome Outlet and compost pits and  Gas main outlet and valve, pipeline,

water fittings, gas stoves, lamp and similar appliances run on bio gas.

Feeder (Raw materials) from the Feeder (Raw materials) from the Villages Villages Cow dung Human waste (link latrine to the Gas plant)Animal waste livestock and poultry wastes, night soil,

crop residues, food-processing and paper wastes, and materials such as aquatic weeds, water hyacinth, filamentous algae, and seaweed.

Construction Process…Construction Process…

First a pit is dug, perhaps ten feet deep. Then a water-tight cement cylinder (with brick or gravel) is constructed. Next, a wall is built across the middle, extending up from the bottom, not quite to the top. Intake and outgo pipes are installed. The whole unit is water-tight.

The manure is mixed with water in the Intake basin to make a slurry, which then goes down the pipe to the bottom of the left side. This side of the cylinder gradually fills and overflows to the right side. Meanwhile, the whole mass bubbles methane up to the top. It collects under the large metal bell-like cover. The gas builds pressure, and can be taken off through a rubber tube to a gas stove in a kitchen.

Model of Gas plant

When both sides of the cylinder are full, the effluent flows out from the bottom of the right side each time more raw manure is added to the left. What comes out on the right is of more value as fertilizer than the raw manure. So the methane is an added byproduct literally "something for nothing," once the capital expense of the construction is paid.

Cost estimate…Cost estimate…

Sl. no.Capacity of

plantretention

period Unit cost

1 1 cu. m 40 days 4700/-

2 2 cu. m 40 days 6500/-

3 3 cu. m 40 days 7600/-

4 4 cu. m 40 days 8700/-

Subsidy available to VillagesSubsidy available to Villages

Size of Plant (in cu.

m)

 Central subsidy for SF, MF AL SC ST Hilly

areas

Central subsidy

for others

State subsidy under Anila Yojane SF MF AL SC ST

Hilly areas

State subsidy for Hilly

areas not approved

from central

government Total

1 2300 1800 1500 2000 3800

2 2300 1800 3500 4000 5800

3 2300 1800 3500 4000 5800

4 2300 1800 3500 4000 5800

Advantages Advantages

(a) Large cattle population in the countryside ensuring steady source of supply of the raw material required for running the gas plant.

(b) Helps in reducing the deforestation as it arrests for cutting of trees for firewood.

(c) Helps in maintaining ecological balance.(d) Helps in rural sanitation(e) Lower capital cost and almost cost free

maintenance.(f) Removes drudgery of women.

Uses of Gobar Gas…Uses of Gobar Gas…

Generally the uses of the gas can be as under 1) cooking

2) lighting 3) Motive Power a) run pump set b) chalf-

cutter 4) can produce electricity.  Motive Power can be produced by linking

the Gobar Gas to a duel fuel engine, specially designed for Gobar Gas.

Courtesy Courtesy

http://www.unu.edu/unupress/unupbooks/80434e/80434E0k.htm