1. Gobar Gas Plant construction
Class IX

2. 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. 

3. 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.

4. Construction Technique – Need to keep in Mind
Site Selection
Digging of the pit
Foundation laying 
Machinery construction work
Laying of pipeline and accessories
Precautions in lying pipelines.

5. A lay out Model of Gobar gas plant

6. Components required for Bio gas plant
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.

7. Feeder (Raw materials) from the 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.

8. 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.

9. 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.

10. Model of Gas plant

11. 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.

12. Cost estimate… Sl. no. Capacity of plant retention period Unit cost 1
1 cu. m
40 days
4700/- 2
2 cu. m
6500/- 3
3 cu. m
7600/- 4
4 cu. m
8700/-

13. Subsidy 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
3500
4000
5800 3 4

14. 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.

15. 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.

16. Courtesy