Fuel Gas From Cow Dung

People living in remote areas of South-East Asia, or other tropical or sub-tropical countries, where electricty is not available and fuel is hard to get, have a very cheap, abundant and efficient fuel in the gas produced from ordinary cowdung. This gas (marsh gas or methane) is generated with the greatest ease simply by letting a slurry of cowdung and water ferment in a ;Yell-like pit without exposure to air. The gas rises LO the surface and collects in a drum, whence it is piped to the kitchen stove. A farmer with a couple of bulls or buffaloes for ploughing and one or two cos for milk gets enough dung every day to produce sufficient gas for all the cooking needs of a village family of six. The cooking is clean and hygienic, the pots do not get black, there is no smoke or smell, and the gas is non-toxic. And after extracting the gas to cook his food, and to light his house at night, the farmer still has all the dung left, well fermented and rotted, to fertilize his fields.

Fresh cowdung, or other animal dung (from horses, mules, donkeys, buffaloes, yaks, Pigs, pou3try) diluted with water and fermented by bacterium methanogenes, without exposure to air, delivers 90% of its potential gas within a period of four weeks, more than half of it within the first eight or ten days. Six weeks of fermentaticn produces about 98%. Hence the fermenting pit, in which daily additions \,f slurry enter at the bottom and gradually raise to overflow at the top, should be large enough to hold each day's addition for a minimum of four weeks or a maximum of six, i.e. from 30 to 40 days. In other words, the volume of the pit should be at least 30 times, or better 40 times, the volume of siurrjr added daily.

Rev. Saubolle is the pioneer of biogas in Nepal. His oil drum plant, built in 1960 at St. Xavier's School in Godavari, twenty kilometers south-east of Kathmandu, was used for boiling tea, which "Father" offered to his guests. The biogas plant offered brilliant demonstration of fuel from waste long 'before it became "fashionable". Many of us here in Nepal were inspired by his pioneering work. Late Rev. B.R. Saubolle, S.J. 1904 - 1982