Gap Analysis of WtE Technologies for Tropical MSW: A Systematic Review and Development Direction of Waste Heat Recovery-Based Hybrid Architectures

Abstract

The management of tropical Municipal Solid Waste (MSW) with extreme moisture content (>60%) presents a fatal thermodynamic challenge for conventional waste-to-energy (WtE) facilities. The “wet waste penalty” phenomenon in stand-alone incineration systems triggers massive latent heat absorption, resulting in systemic inefficiency and high exergy destruction wasted through the flue gas stack. This paper presents a targeted systematic review of the primary literature to dissect the research gap between the potential of thermochemical technologies and their rational implementation in developing nations. Analysis confirms that advanced technologies face irrational capital expenditure (CAPEX), while stand-alone systems approach asymptotic efficiency limits. As a resolution, this study proposes a retrofitting-based hybrid architecture for incineration-pyrolysis that utilizes the flue gas recovery route (200°C–300°C). This sensible heat extraction fully subsidizes the pyrolysis reactor's activation energy without interfering with the main steam cycle (zero steam bleeding). This hybrid integration effectively recycles exergy destruction, boosting overall thermal efficiency and providing a dual output of baseload electricity and high-density hydrocarbons, making it a realistic energy-circularity transition scheme for existing WtE infrastructure.