Fuel made from cow manure

Press, Volume CXIV, Issue 33514, 20 April 1974, Page 12

Fuel made from cow manure

I By

JAGAN NATH)

NEW DELHI. In parts of rural India remote from modern amenities and oil crises, farmers are solving their own fuel problems by turning their cows to the production of light and power as well as milk. Simple but efficient extraction plants are operating in five states to transform cattle manure into methane gas. The system has been taken up by the Central Government and tens of thousands more installations are planned. Anybody with five cattle can be in business as his own gas supplier. This minimum herd provides the 45 kg of fresh dung which the smallest conversion plant needs daily to supply a gas cooker and a few house lights. Bigger herds provide fuelling on a more ambitious scale.

Traditionally Indian peasants burn cattle manure as solid fuel, a wasteful and uneconomic process.

8000 plants

Today, 8000 gas-extraction plants are working in Tamil Nadu, Karnataka, Kenala. Gujerat and Madhya Pradesh states. Some $3 million has been advanced in loans and grants for their construction. The plants produce over 10 million cubic metres of gas a month, valued at over ,$50,000. During India’s fifth five-year-plan about 40,000 more plants are projected. The plants have a life of 30 years. Not only is gas for heating and lighting produced but there is a large residue of enriched humus when the manure has finished its gas-making fermentation. India has an estimated 220 million head of cattle yielding enough manure to increase the country’s food production by 10 million tons a year.

Soil enrichment The gas extractor plants, called gobar, provide light and heat and still leave the manure available for soil enrichment. In fa'ct, the residue is found to have higher nitrogen content than when fresh. Farmers may get 25 to 30 per cent more yield by using gobar

gas manure.

The gobar plant also reduces firewood consumption, Every year vast areas in the countryside are denuded of trees by the use of wood for fuel in addition to the domestic burning of manure.

The plant comprises two main parts: the digester and the gas holder. The digester is a sort of well, constructed of masonry work below ground with inlet and outlet pipes. Models vary from 60 to 250 cubic feet dung capacity. The .dung, mixed with water in the proportion of 4 : 5, is poured in and after fermentation the gas bubbles up through the outlet pipe into the gas holder. The holder comprises two or more drums, one inside the other, made of sheet steel and fitting tightly over l+ie mouth of the well.

As the gas pressure grows the container rises to accomodate it. The gas, 55 per cent methane, is led off through a pipe at the top to a kitchen cooker and to house-lamps. It may also be used to run engines. The first gobar plant was developed experimentally at the Indian Agriculture Research institute 30 years ago, but only in 1964 was it tried out on farms. Now, mass construction is contemplated and a programme of educating peasants away from the ageold habit of burning manure must go with it.