Perspective review on Municipal Solid Waste-to-energy route: Characteristics, management strategy, and role in circular economy

Abstract

The proper handling of Municipal Solid Waste (MSW) is critical due to its high generation rate and the potential to minimise environmental impacts by simultaneously reducing resource depletion and pollution. MSW utilization for recycling is important for transforming the linear economy model into a circular one. The current review analyses and categorises MSW to energy technologies into direct and indirect approaches taking the Circular Economy perspective. The direct approach involves incinerating MSW for heat recovery. The indirect approach, including thermochemical and biochemical processes , is more complicated but attractive due to the variety of the valorized products – such as syngas , bio-oil, biochar, digestate, humus. However, consensus on the best MSW treatment approach is yet to be established due to the inconsistency of assessment criteria in the existing studies. In the case of converting MSW to energy (Waste-to-Energy – W2E), its economic indicators, such as capital, compliance, and operation cost, are important criteria when implementations are considered. In the current work, the critical characteristics of technologies for the MSW to energy routes are scrutinised. In addition, the economic characteristics and the role of MSW in the circular bio-economy is also thoroughly evaluated. Methods to advocate the industrial adoption and important assessing aspects of W2E are proposed at the end of the review to address the environmental and resource management issues related to MSW – most notably dealing with the uncertainty in composition and amounts, the energy efficiency and the resource demands of the W2E processing. • Direct and indirect valorisation techniques for MSW are reviewed. • The economic characteristics and energy production viability of MSW are analysed. • Suggested assessment criteria for fair comparison of Waste-to-Energy technologies. • The low economic viability of Waste-to-Energy due to ignoring environmental benefits. • Methods to advocate the industrial adoption of W2E are proposed.