Kagando Stove

Multi-Saver Stove, Uganda, 2008.

 

Africadev - Self Help Developments for Africa

   

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Water carrying                             (Top of page)

If you have to carry water maybe a yoke would help, similar to what was used in England years ago.

 
       
       
       
       
       

Biogas:                                          (Top of page)

Wood you like to make your own free fuel gas for cooking?  It is possible:

  • It can be made from animal manure, plant materials, human excrement, kitchen waste, or a mixture of any of these.

Production of biogas has many advantages:

  • It is free to make, once you have built or bought the tanks for production and storage.
  • It is a clean burning fuel, producing no smoke, thus giving a cleaner kitchen and cleaner air to breathe.
  • It saves on the use of heavy, bulky, expensive fuels such as kerosene, wood or charcoal.
  • The material left after all the gas has been made is a very rich fertilizer that can be used on the fields.
  • Biogas digesters are a safe way of disposing of animal and human dung.
  • Anaerobic decay in bio-digesters produces less less harmful greenhouse gases than the alternative aerobic decay in heaps.

But there are disadvantages:

  • The tanks for production and storage can be expensive.
  • There is a small risk of explosion, so produce and use with care.
  • It is a complicated process, requiring effort, time and some money to start, and no guarantee of success.
  • Biogas is best produced at temperatures between 32-37 degrees C, and will not work below 15 degrees C.
  • Biogas, or methane, is not toxic, but should not be breathed.
  • Biogas production has been recommended for at least 25 years - but it appears not to be in widespread use - so maybe it is not a viable way of producing fuel.  By 1993 approximately 5.25 million farmer households had biogas digesters, producing 1.2 billion cubic metres of methane and 3500 KW of electricity. (ITDG)  (Please email me if you produce and use biogas - we would love to hear from you.)
  • Large volumes are required: 1 cubic metre could cook 3 meals for a family of 6 (ITDG)  1 lb cow manure could produce 1 cubic foot of gas - enough for a day's meals for a family of 5 in India.

To build a small, experimental biogas unit you will need:

  • Two drums that fit inside one another - a standard 200 litre oil drum, and a smaller 120 litre drum are good.
  • A piece of metal pipe approximately 10 centimetres long, and 2 centimetres diameter, for the gas outlet.
  • A valve to fit this gas outlet.
  • At least 10 m of rubber or plastic tube about 2 cm in diameter.

Location of your biogas plant:

  • Approx. 10 m from your home  - to avoid smells.
  • Approx. 5 m from your cooking area - to reduce the length of the gas line.
  • 15 m from your water supply, to avoid pollution of your water.
  • If you live in a very hot place put the unit out of the sun, in the shade of a tree or building.
  • If you live in a cool place put the unit in the sun, or even underground or covered with earth or straw. 

How to build the unit  (See the link for more detailed instructions on How to build a small scale example digestor):

Size and capacity:

  • A 1 cubic meter digester requires 25 kg cow dung daily, from 2-3 cows, and will supply 2-3 persons with enough gas.

Links:

  • A detailed description, with costs and pictures, of a sophisticated plant in India ($30,000, 2007).
  • Detailed analysis of costs and benefits, in India 2007 (ROI)
  • The worlds 900 million cars and commercial vehicles cause less global warming than the world's 1530 million cows (FAO, from ROI p18)
       
       
       
       
       
       
 

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