An integrated multi-objective optimisation framework for municipal solid waste management and emissions trading scheme

Sustainably managing municipal solid waste (MSW) is a global challenge since the existing MSW processing procedure releases greenhouse gases and is economically unfriendly. An emissions trading scheme (ETS) is a market-based approach for policymakers to reduce sectoral carbon emissions while maintaining economic efficiency. Hitherto, no waste optimisation framework links ETS to carbon reduction and identifies the trade-offs between the cost of carbon credit trading and waste expenses, rendering doubt of ETS's effectiveness in the waste sector. In this study, an MSW-ETS framework is developed to analyse the potential impact of ETS on the MSW management system incorporating multiple waste types, disposal and treatment facilities, and waste-based products. A multi-objective optimisation model is integrated with the MSW-ETS framework to achieve mutual environmental and economic benefits. Malaysia is selected as an illustrative case study considering its unsustainable MSW disposal and the recent carbon trading plans announced by the government. Simulation of the carbon prices alters Malaysia's MSW management configuration at 363 MYR/tonne CO2-eq, providing insights on developing the carbon price floor for a Malaysian ETS. Six MSW management configurations under different scenarios that can achieve up to 160% GHG emissions reduction were also proposed. The MSW-ETS framework integrated with the multi-objective optimisation model could be replicated by other countries planning to phase the waste sector into ETS coverage.