Demonstration-scale CO2 capture and liquefaction at the Amager Bakke waste-to-energy facility with monoethanolamine, Part one: Efficiency, CO2 purity, and emission control

The integration of CO 2 capture at waste-to-energy (WtE) facilities can provide carbon-neutral electricity and district heating, and treat residual waste streams. However, before full-scale implementation, a better understanding of the production of liquid CO 2 and emissions from the capture process is required. This study investigates the performance of a CO 2 capture demonstration-scale unit, including CO 2 liquefaction at the Amager Bakke WtE facility, covering topics including efficiencies, CO 2 purity, and emission control. The demonstration unit has a capacity of 4 t CO 2 d − 1 and is capable of capturing and conditioning CO 2 to food-grade-compliant purity for utilization by local consumers. The unit was operated for five months, using 35 wt% monoethanolamine (MEA) solvent. During the five months of operation, seven experimental campaigns with different objectives were conducted to optimize energy performance, evaluate flue-gas emissions, and monitor the quality of the produced CO 2 . Across 2002 h of on-stream time the specific reboiler duty (SRD) averaged 3.73–4.18 GJ t CO 2 − 1 , fully consistent with the best values reported for 30–35 wt% MEA systems. Production of liquid CO 2 totalled 193 t CO 2 , corresponding to an 84 % overall recovery, while a 12 % loss was observed between absorber and storage tank. The specific solvent consumption was 2.43 kg MEA t CO 2 − 1 . The most significant contributor to solvent loss was oxidative degradation to NH 3 . Peak NH 3 slip reached 75 ppmv and showed a positive correlation with both absorber temperature and dissolved‑iron level (up to 600 mg L − 1 ). Lastly, the effect of thermal reclaiming is qualitatively reported. Finally, the purity of the produced liquid CO 2 for export was measured and compared with the degradation of the solvent. All consignments met Northern Lights transport limits and EIGA beverage-grade specifications; typical impurities were <5 ppmv O 2 , <1 ppmv SO x , and <0.05 ppmv amine. We produced high-purity liquid CO 2 , with impurity levels in compliance with commercial CO 2 specifications, but found significant challenges related to amine degradation that must be solved before full-scale implementation. • Demonstration-scale CO 2 capture and liquefaction at Amager Bakke WtE • Achieved solvent consumption of 2.43 kg MEA per ton of CO 2 captured • Produced CO 2 met commercial purity standards for industrial use • Oxidative degradation was the main cause of solvent loss. • A correlation was found between solvent degradation and NH 3 slip.