Pilot-Scale CO ₂ Capture Study at a WtE Plant: Parametric Analysis, Emission Mitigation, 750 h Operation, and Cost Assessment

The first pilot-scale waste-to-energy (WtE) flue gas carbon capture system in China, with an annual CO 2 capture capacity exceeding 1000 tonnes, has been successfully designed and commissioned. On the basis of the proprietary amine-based absorbent LONGAN-1, a systematic evaluation of key operating parameters was conducted to elucidate their interactive effects and identify optimal operating conditions. Under optimized operation, the CO 2 capture efficiency reached 95.0%, with a specific reboiler duty (SRD) of 2.87 GJ/t of CO 2 . In addition, a continuous 750 h stability test demonstrated no discernible deterioration in the capture efficiency and SRD. While impurity ion concentrations increased during operation, the total remained below 0.5%, and the amine loss was limited to 0.41 kg/t CO 2 . To further mitigate amine emissions, the condensate from the gas–liquid separator was routed to the water-wash section, reducing the amine concentration in the absorber outlet flue gas from 11.5 to 4.5 mg/Nm 3, which was lower than that of the conventional MEA solvents and met amine emission standards in China. Finally, a preliminary techno-economic assessment indicated an operating cost of 34.22 $/t CO 2, with input thermal energy accounting for 54.2% of the total cost, substantially lower than conventional MEA-based systems. This work provides the first comprehensive pilot-scale data set for WtE flue gas CO 2 capture in China, offering practical insights for industrial-scale implementation.