Biogas Upgrading and Bottling Technology for Vehicular and Cooking Applications - Management of Natural Resources in a Changing Environment - page 131

that of the feedstock fed in a biogas plant. This slurry can be dried and sold as high
quality compost. This means increased income for the farmers.
Biogas Production in India
Small scale digestion plants using primarily animal wastes have seen widespread
use throughout the world, with many plants in developing countries. These plants
are generally used for providing raw biogas for cooking and lighting for
households.
In India, widespread options of biomethanation organic wastes are available.
Presently, out of 960 million tonnes of solid waste being generated annually, around
350 million tonnes are organic wastes generated from agricultural sources. A wide
range of organic wastes are available which are widespread throughout the nation.
Rapid industrialization and increase in population has resulted in the generation of
huge quantity of wastes, both solid and liquid, in industrial sectors such as pulp and
paper, fruit and food processing, sugar/starch, distilleries, dairies, tanneries, slaugh-
terhouses, poultries, etc.
Despite requirements for pollution control measures, these wastes are generally
dumped on land or discharged into water bodies, without adequate treatment, and
thus become a large source of environmental pollution and health hazard. These
include animal/agro waste, human waste, wastes from agro-based industries (paper
and pulp production, sugarcane processing, distilleries, and other food and food-
processing industries).
Biogas, therefore, is an obvious choice and has a very promising future in India
due to the tropical location and very high population of livestock of over 300 mil-
lion. Use of cattle dung is widespread in rural areas either as cooking fuel in the
form of dung cakes or as compost. This resource, when used through biomethana-
tion route, can provide biogas as clean fuel and digested slurry as good quality
compost (Fig. 1 ).
An estimate indicates that India has the potential of generating 6.38 × 10 10 Nm 3
of biogas from 980 million tonnes of cattle dung produced annually (Vijay et al.
2006 ). If organic wastes such as sewage, MSW, industrial effl uent, and distillery
wastes are also taken as feedstock for biogas production, the total biogas potential
would increase further. There are around 300 distilleries throughout India which
collectively have a potential of producing 1,200 million Nm 3 biogas, and 2,000 tan-
nery units capable of producing 787,500 Nm 3 of biogas (MNRE 2001 ). The increas-
ing number of poultry farms can also add to biogas productivity as with a current
population of 649 million birds, another 2,173 million Nm 3 of biogas can be gener-
ated (Mittal 1996 ). Different categories of urban municipal and industrial organic
wastes and their estimated quantity available in India are shown in Table 1 .
Since there is widespread availability of organic wastes in India, biogas can be
produced at different scales. India has a vast potential of biogas production