Biogas plants running on cow power

by Dave

Yesterday, there was a newsbrief about how cow manure can be used to generate 3 percent of North America’s electricity needs while significantly reducing greenhouse gas emissions. This technology is not news to Indian villagers who have been using Gobar Gas for decades. Doing a little digging I came across this interview (conducted in 1972!) with India’s pioneer in the design, construction and roll-out of low-cost biogas plants that use cow manure. For farmers in Argentina, Uruguay and Brazil with huge cattle populations it makes sense to consider Indian biogas technology for price-performance considerations.

The Plowboy Interview(1972) – Ram Bux Singh

Ram Bux Singh has developed a keen interest in helping to design, construct and promote the use of bio-gas plants here in the United States. “Two billion tons of manure is wasted annually in the U.S., ” he says, “and that is actual food and actual power that you could save with the inexpensive composters we have developed in India.’

PLOWBOY: But you have been experimenting with methane conversion for some time and your work in the field is considered quite important by scientists and technicians all over the world. Obviously you’ve contributed something of value to the search for ways to recycle waste into non-polluting fuel.

RAM BUX SINGH: In 1955, the government of India appointed me to simplify the construction of bio-gas plants. There was no question that such units would produce
methane but, up to that time, most gas generators were very large and costly. Even the small plants built in Germany during the war were quite expensive. So what we have done at the Gobar Gas Research Station in India is to simplify the construction of bio-gas generators.
We have designed efficient plants that are small enough for a single
village or one farmer to build and we have found ways to construct
these gas generators for very little money. We have made the bio-gas
plant economical for small farms.

Let me give you an example of what we have done. When recently visited a
sewage plant at Charleston, West Virginia, the engineer there told me
that seventy million dollars had been spent on the facility. If we were
to try to scale down to: village or farm size the technology used in
that plant, the smaller waste disposal unit might still cost half a
million dollars Now, no village in India and no farmereven in the United Statesis
going to spend a half million dollars to process waste. But we have
designed bio-gas plants which both purify waste and produce
non-polluting fuel . . . and some of these units can be built for as
little as $100
! With our designs and a relatively minor investment,
then, a farmer or small group of people can now construct a
self-contained system that will recycle plant and animal waste into
high-quality fertilizer anti non-polluting fuel. The fuel can then be
used to cook with, to heat the farmhouse and to power machinery. A
bio-gas plant can make a farm more self-contained and independent.

PLOWBOY: It’s this idea of homemade power, you know, that has excited so many people in this country. The idea of running a car or heating a house with non-polluting fuel that is generated from waste right in one’s own back yard is tremendously attractive to individuals fed up with oil spills, strip mining and smog. Yet I notice that you emphasize the fertilizer produced by a bio-gas plant just as much as you emphasize the methane which comes from such a unit.

RAM BUX SINGH: Oh yes. The fertilizer is very important, especially in a country like India where the farmers do not have so much money with which to buy chemical plant food. You are rich enough here[in the U.S.]to purchase the commercial fertilizer and you do not think so much of conserving the natural nutrients for your crops. But I believe you will. As your population increases and you farm more intensively and the movement to cooperate with nature gains strength in the United States, I believe you will think more and more about conserving your natural plant foods. You will begin to think more and more of the bio-gas plant as a source of both power and high-quality fertilizer.[

PLOWBOY: What do you mean by “high-quality”?

RAM BUX SINGH: We have calculated through many university lab tests in India that the fertilizer which comes from a bio-gas plant contains three times more nitrogen than the best compost made through open air digestion. If you compost chicken manure, for example, the finished compost will have in it only 1.58 to 2%o nitrogen. The same manure digested in a bio-gas plant will analyze 6% nitrogen.

PLOWBOY: Where does this extra nitrogen come from?

RAM BUX SINGH: It is already in the manure. The nitrogen is preserved when waste is digested in an enclosed bio-gas plant, whereas the same nitrogen evaporates away as ammonia during open air composting. The bio-gas plant does not make extra nitrogen; it does not create nitrogen . . . it merely preserves the nitrogen that is already there.

PLOWBOY: OK. I can see how the nitrogen is caught and contained when plant and animal waste is digested inside a closed bio-gas plant, but what about other elements? Is anything lost or eaten up by the bacteria in the tank? Do they take anything out of the organic material so that, over a period of years, you’ll be putting back less and less on the fields you fertilize with waste processed in a bio-gas plant?

RAM BUX SINGH: No, nothing is used up. This is the perfect fertilizer-making machine and it has been tested all over the world. There is no better way to digest or compost manure and other organic material than in a bio-gas plant. I think you can compare the bacteria in a digester tank to fish worms. Fish worms help the soil by eating organic matter, passing it through their bodies and expelling it as very rich fertilizer. They live by breaking waste material down into food for plants. It is the same with the bacteria in a methane digester.

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