Sintex seeks to solve India's energy and sanitation problems in one stroke - with biogas digesters

[JohnWxy]

http://money.cnn.com/2008/02/26/news/international/kahn_biogas.fortune/index.htm

(Fortune Magazine) -- Sintex Industries, a plastics and textiles manufacturer in Gujarat, India, is betting it can find profit in human waste. Its new biogas digester turns human excrement, cow dung, or kitchen garbage into fuel that can be used for cooking or generating electricity, simultaneously addressing two of India's major needs: energy and sanitation.

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The future can be glimpsed on a dusty, rutted road in a poor South Delhi neighborhood. Here 1,000 people use an immaculately clean public toilet constructed by a nonprofit foundation, the Sulabh Sanitation Movement. The biogas digester attached to toilets provides cooking gas for a 600-student school and vocational-training program the foundation runs. In the past, nongovernmental organizations like Sulabh were the only ones offering biogas digesters.

But Sintex is hoping cities, real estate developers, building managers, and hospitals will jump at a ready-made way to harness the same energy.

http://www.habmigern2003.info/biogas/methane-digester.html">Anaerobic Digesters for Methane production

[Fledermaus]

1. FYI, biogas has an octane of 120-140! The byproduct of a digester is a high grade fertilizer.

How much carbon does the fertilizer displace when compared to fertilizer made from natural gas?

Nitrogen and Carbon wise, biogas is double plus good!

[amandabeech]

2. The fertilizer resulting from the digestion of human waste cannot be used

in the same way that fertilizer from animal or kitchen wastes can be used.

It takes two years to produce something from human waste that can be spread on the ground. However, it should not be spread on ground that is to be planted with crops for direct human consumption. It should only be spread on ground that is to be used for pasture or planted with feed crops.

The other fertilizer will likely have a fairly low nitrogen component because the nitrogen (ammonia) evaporates fairly quickly, but it will replace a significant portion of the amount of nitrogen that the farmers in India probably use. In addition, it will undoubtedly provide the phosphorus, potassium and trace minerals that are necessary for plant growth and that are probably imported and expensive.

Biogass digesters are becoming more popular here, as I'm sure you've noticed, but the resulting fertilizer is quite dilute and requiring special equipment in order to apply it to farm fields.