Selection and economic evaluation of appropriate technology to generate electricity from household waste of Dhaka-Mirpur cantonment area

Abstract

Solid waste disposal poses a greater problem because it leads to land pollution if openly dumped, water pollution if dumped in low lands and air pollution if burnt. Moreover, the scarcity of land and increasing of land prices especially in Dhaka City creates the problem of developing any new landfill site. The sustainable strategy for the waste management is to improve waste treatment in the aim to reduce their landfill disposal, minimize the environmental impact and recovery of energy to mitigate the energy crisis of the country. Selection of appropriate waste conversion technology can be complicated due to the intrinsic trade-off between sociopolitical, environmental, and economic factors. Realizing the existing and future impact of waste disposal issue, Analytical Hierarchy Process (AHP) technique has been used to select an appropriate Waste-to-Energy (WTE) conversion technology for household waste of Dhaka-Mirpur Cantonment area. Technological, Environmental and Financial criteria were selected for AHP analysis in this study. Three alternatives, namely, Anaerobic Digestion (AD), Pyrolysis and Plasma Gasification (PG) technologies were chosen for comparison. The analysis reveals that Plasma Gasification is a viable option for waste treatment in Dhaka-Mirpur Cantonment area. The advantages that plasma gasification offers outweighs most other conventional technologies in that the system has a relatively small footprint, can treat unsorted waste and can produce good quality synthetic gas without extremely toxic by-products. In case of Economic evaluation, both tangible revenue from electricity sale and intangible benefits in terms of Renewable Energy Credit (REC) and Health and Environment Benefits (HEB) were considered. The overall Benefit-Cost Ratio (BCR) is very lucrative and can be comparable with any other waste management system.