Is anaerobic digestion of municipal garbage to produce biogas economically feasible ?

Abstract

The problem of collecting, transporting and disposal of market and domestic garbage is probably the greatest problem confronted by many municipalities and local authorities. The dumping of garbage in solid waste dumps without proper evaluation of the environmental and health hazards of such dumps has lead to protests by the public and many environmentalists. Moreover, such dumps, while causing major environmental and health problems to the people living within close proximity, have ruined the landscape and the aesthetic beauty of the land. They have become the breeding grounds for cats, dogs, rats, reptiles, insects, mosquitoes and flies, too. Safe and efficient collection, transport and disposal of garbage has been the subject of many seminars, conferences and workshops. There are many diverse views on what process is the best, to dispose garbage. Anaerobic digestion of municipal garbage to produce biogas, has been mooted as the solution to the municipal garbage problem in Sri Lanka, by many engineers and scientists. However, the technical and economical feasibility of biogas manufacture from municipal garbage, has yet to be properly established, by those who have done research and development work in this area. This paper critically evaluates the NHRDC (National Engineering Research and Development Centre) Dry Batch Biogas Syatem, which has been described by the NERDC as a better system for biogas production than the Chinese and Indian biogas systems. The paper also presents data and appropriate scientific calculations, which leads to the conclusion that anaerobic digestion of garbage to produce biogas by dry batch technology, is not economically feasible, and recommends that further capital investment should not be made, either by the government sector or by the private sector to establish new biogas plants, using this system.