Cost-benefit analysis of technological changes: case of a management solid waste consortia in the metropolitan region of Curitiba, Brazil

ABSTRACT Huge increases in the volume of waste produced by society have created an urgent need for new and improved municipal solid waste (MSW) processes. In many countries, traditional methods to manage MSW, such as landfills, have been abandoned in favor of more effective and environmentally efficient technologies. These include gasification (decomposition at high temperatures), recycling, and composting (of organic matter). The purpose of this research was to assess certain financial, social, and environmental indicators, especially the IRR and cost-benefit ratio of changing the technologies used in MSW processing. The research focuses on assessing these changes in the CONRESOL area — a consortium that covers almost all the municipalities in the metropolitan region of Curitiba, Brazil. To this end, scenarios were proposed that apply various technological combinations and two collection fees. Of the three proposed scenarios, the one with the best socioeconomic and environmental results (Internal Rate of Return, Net Present Value, Discounted Payback, and Benefit/Cost ratio) combines gasification, recycling, and composting. This scenario generated the least GHG emissions and the highest number of jobs.