This is estimated to touch 57.0 million tonnes in 1990 and 1991 and 92.0 million tonnes by 2000 A.D. This indicates considerable shortage in energy supply during the coming years (Vimal, 1986).In the third world, biomass is used mainly as fuel wood by over 90% of the population. The world's total yearly supply of fuel wood, which is more than double in the last 40 years up to 1950, is estimated to have leveled off at about 1070 million m3per cent thereafter (Lewis, 1981). Tropical forests in the world are estimated to be vanishing at an annual rate of about 7 million hectares while the corresponding rate for woodlands in the semi- steeply sloping terrain receiving substantial rainfall, as well as in arid and semi-arid zones, clear cutting of forests and woodlands is followed by severe water and wind erosion and land degradation. In India, 68.5% of the energy used in households isfrom the firewood and 64.2% of it is collected from natural sources. The shortfall in fuel production is likely to rise to 137 million tonnes in 2000 A.D. from the present 84 million tonnes (Vimal, 1986). The indiscriminate felling of trees has reduced the forest cover to 23% against 33%during the last decade. The annual production of dry dung is of the order of 350 million tonnes from about 240 million cattle, which is capable of generating 70 billion cubic meters of gas annually in biogas processing plants.