Bury, burn, or gasify: assessing municipal solid waste management options in Indian megacities by exergy analysis

With increasing consumption propelled by economic prosperity, waste generation per capita in developing countries is growing quickly. Traditional approaches of open dumping and landfilling are encountering physical constraints, particularly in megacities, and the need for alternate municipal solid waste (MSW) management strategies is urgent. Among alternatives that are commonly considered are waste-to-energy technologies including incineration and plasma gasification. Previous studies convey the benefits of such technologies, but most do not consider the waste and environmental conditions in tropical megacities such as Mumbai, India, making these studies of limited use to developing countries. This article evaluates the exergetic potential of converting MSW to useful work by thermal and biochemical conversion technologies in the Indian context, considering the facts that the scale of production, composition, climate, segregation practices, moisture content of MSW, etc. in a developing tropical country like India differ significantly from those in developed societies in temperate climate locations. Both, exergy and economic analysis find gasification to be attractive in terms of its monetary return and thermodynamic efficiency. However, this analysis also identifies major hurdles in adopting advanced waste-to-energy technologies including lack of waste segregation, high moisture content, and high capital cost of the most thermodynamically efficient technology.