Carbon capture for waste-to-energy: Integration pathways, challenges, and opportunities for net-negative systems

Waste-to-Energy (WtE) plants reduce landfill volumes and provide reliable energy, yet incineration emits CO₂. This review examines how carbon capture can be integrated with WtE to lower stack emissions and, when the biogenic fraction is permanently stored, enable net-negative outcomes. Capture routes are summarized with emphasis on post-combustion absorption and oxy-fuel combustion, which have the most direct evidence for WtE integration. Key implementation barriers are mapped, including variable waste composition, process control requirements, energy penalties, product-gas purity, retrofit constraints, costs, and life-cycle trade-offs. Environmental aspects are discussed through life-cycle assessment and the requirements for measurement, reporting, and verification of the biogenic fraction. The review identifies near- and medium-term opportunities: cryogenic retrofits suited to corrosive flue gases and high-purity CO₂, molten carbonate fuel cells that capture CO₂ while generating power, advanced solvents with process intensification, and AI-enabled optimization and digital twins to manage variability. Coupling verified biogenic removals with avoided landfill methane and low-carbon energy revenues can strengthen project viability. Overall, appropriate technology selection, heat integration, robust controls, reliable CO₂ transport and storage, and transparent carbon accounting provide a credible pathway from current WtE systems to net-negative configurations.