Analysis of the performance of Air Pollution Control residues as CO2 sorbents in the calcium looping process
Year: 2026
Type: article
Abstract: • APC residues of different origins are tested as CO 2 sorbents in calcium looping. • CO 2 uptake is determined by Ca content and decreases with cycles due to sintering. • F- and S-bearing phases reduce carbonation via diffusional limitations. • Cl-containing phases determine complex cyclic behavior due to salt melting effects. • APC residues retain up to 140 mg CO 2 g −1 after 10 carbonation–calcination cycles. Air Pollution Control (APC) residues deriving from acid gas (HCl, HF, SO 2 ) removal processes are typically disposed of in hazardous waste landfills. This study explores the potential reuse of these residues as alternative CO 2 sorbents in the Calcium Looping process, leveraging their content of unreacted lime. APC residues originating from different industrial sources (waste-to-energy, ceramic, and glass plants) were subjected to multiple carbonation–calcination cycles and benchmarked against a reference hydrated lime. The observed performance was linked to the morphological and compositional variability of the residues. Ceramic APC residues exhibited an inverse correlation between CO 2 uptake and the presence of stable fluorinated and sulfated phases. The monotonic decline in CO 2 carrying capacity upon cycling was ascribed to sintering. Waste-to-energy residues displayed a more complex cyclic behavior, associated with the melting of chlorinated phases under calcination conditions and the consequent rearrangement of product layers on sorbent particles. Despite their lower performance compared to virgin hydrated lime, APC residues achieved up to 140 mg CO 2 /g sorbent after 10 cycles.
Source: Waste Management
Institution: University of Bologna
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,450
OpenAlex ID: W7128008181