Rohan the Director of Petro Chemical Company wants from produce Bio Gas from waste garbage and useless material. He decides that this manufacturing unit will be set up in rural and backward area of Bihar where people are suffering from poverty and unemployment. Rohan wants to deploy people from local surrounding areas. He also wants to give opportunity to the persons qualified from technical institutions to join his unit. 1. Identify the function of Management which is concerned with deployment of personnel in his unit. 2. Identify the sources of recruitment used quoting the lines from above para.
Answers
Answer:
What is biogas?
It mainly comprises of hydro-carbon which is combustible and can produce heat and energy when burnt. Bio-gas is produced through a bio-chemical process in which certain types of bacteria convert the biological wastes into useful bio-gas. Since the useful gas originates from biological process, it has been termed as bio-gas. Methane gas is the main constituent of biogas.
Biogas production process
The process of bio-gas production is anaerobic in nature and takes place in two stages. The two stages have been termed as acid formation stage and methane formation stage. In the acid formation stage, the bio-degradable complex organic compounds present in the waste materials are acted upon by a group of acid forming bacteria present in the dung. Since the organic acids are the main products in this stage, it is known as acid forming stage. In the second stage, groups of methanogenic bacteria act upon the organic acids to produce methane gas.
Raw materials for biogas production
Although, cattle dung has been recognized as the chief raw material for bio-gas plants, other materials like night-soil, poultry litter and agricultural wastes can also be used.
Advantages of biogas production
It is a eco-friendly fuel.
The required raw materials for biogas production are available abundantly in villages.
It not only produces biogas, but also gives us nutrient rich slurry that can be used for crop production.
It prevents the health hazards of smoke in poorly ventilated rural households that use dung cake and fire-wood for cooking.
It helps to keep the environment clean, as there would be no open heap of dung or other waste materials that attract flies, insects and infections
Availability of biogas would reduce the use of firewood and hence trees could be saved.
Components of biogas plants
Mixing tank - The feed material (dung) is collected in the mixing tank. Sufficient water is added and the material is thoroughly mixed till a homogeneous slurry is formed.
Inlet pipe - The substrate is discharged into the digester through the inlet pipe/tank.
Digester - The slurry is fermented inside the digester and biogas is produced through bacterial action.
Gas holder or gas storage dome - The biogas gets collected in the gas holder, which holds the gas until the time of consumption.
Outlet pipe - The digested slurry is discharged into the outlet tank either through the outlet pipe or the opening provided in the digester.
Gas pipeline - The gas pipeline carries the gas to the point of utilization, such as a stove or lamp.
Points to be considered for construction of a biogas plant
Site selection
While selecting a site for a biogas plant, following aspects should be considered
The land should be levelled and at a higher elevation than the surroundings to avoid water stagnation
Soil should not be too loose and should have a bearing strength of 2 kg/cm2
It should be nearer to the intended place of gas use (eg. home or farm).
It should also be nearer to the cattle shed/ stable for easy handling of raw materials.
The water table should not be very high.
Adequate supply of water should be there at the plant site. The plant should get clear sunshine during most part of the day.
The plant site should be well ventilated.
A minimum distance of 1.5m should be kept between the plant and any wall or foundation.
It should be away from any tree to prevent root interference.
It should be at least 15m away from any well used for drinking water purpose.
Availability of raw materials
The size of the biogas plant is to be decided based on availability of raw material. It is generally said that, average cattle yield is about 10 kg dung per day. For eg. the average gas production from dung may be taken as 40 lit/kg. of fresh dung. The total dung required for production of 3 m3 biogas is 3/0.04= 75 kgs. Hence, a minimum of 4 cattle is required to generate the required quantity of cow dung.
Useful Resources
Average maximum biogas production from different feed stocks
Sl. No.
Feed Stock
Litre /kg of dry matter
% Methane content
1.
Dung
350*
60
2.
Night-soil
400
65
3.
Poultry manure
440
65
4.
Dry leaf
450
44
5.
Sugar cane Trash
750
45
6.
Maize straw
800
46
7.
Straw Powder
930
46
Average gas production from dung may be taken as 40 lit/kg. of fresh dung when no temperature control is provided in the plant. One Cu. m gas is equivalent to 1000 litres.
Average dung yield
Sl. No.
Living Beings
Quantity of Dung / Night Soil produced (kg/day)
1.
Cow, Heifer
10.0
2.
Bullock
14.0
3.
Buffalo
15.0
4.
Young bovine
5.0
5.
Horse
14.0
6.
Horse, young
6.0
7.
Pigs, over 8 score
2.5
8.
Pigs, under 8 score
1.0
9.
Ewes, rams and goats
1.0
11.
Lambs
0.5
12.
Duck
0.1
13.
10 hens
0.4
14.
Human beings
0.4
Note :For free grazing animals the availability of dung may be taken as 50 per cent of the amount given in the table