Anaerobic digestion for the stabilization of the organic fraction of municipal solid waste: A review

Anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) has gained great interest in the last few decades. Presently, among the various municipal solid waste management (MSWM) techniques, such as sanitary land-filling, aerobic or anaerobic composting, and thermal incineration, AD is being considered as the most techno-economically viable method owing to its many advantages. AD not only serves to efficiently manage and treat an enormous quantity of OFMSW but also acts as a convenient source of non-conventional energy. The methane generated via AD of OFMSW serves as a potent substitute for fossil-based fuels. Given the current global energy crisis, this technology may be a welcome boost to the global energy demand. In this review an attempt has been made to provide a comprehensive understanding of: (i) the origin and scope of AD of OFMSW; (ii) the potential of AD for OFMSW stabilization; (iii) various pilot and bench-scale studies conducted hitherto; (iv) the process design aspects of AD of OFMSW; (v) the potential of energy recovery from AD of OFMSW; and (vi) the past experiences of AD of OFMSW. This review also delves into the critical issues that govern the process of AD in stabilizing OFMSW. In addition, the compatibility of AD for MSWM in the Indian scenario compared to other classical methodologies, such as landfilling, composting, thermal incineration, and pyrolysis or gasification, is highlighted. An overview of the overall future prospect of AD of OFMSW is discussed.