Oxidative degradation and solvent loss constrain the use of aqueous amines for CO₂ capture in oxygen-containing flue gas. This work aims to develop a novel amine-based CO₂ absorbent with outstanding oxidation resistance and low regeneration energy consumption, addressing the core limitations of conventional absorbents including severe oxidative degradation and high energy penalty in industrial carbon capture scenarios. 
Based on the degradation-resistant molecular structure of 2-amino-2-methyl-1-propanol (AMP), the main amine molecule of HNC-7 was rationally constructed via molecular design methodology. A systematic laboratory evaluation was conducted to characterize its kinetic and thermodynamic properties, with multiple benchmark absorbents as references. Furthermore, 500-hour pilot tests were performed in kiloton-scale carbon capture facilities for both natural gas combined cycle (NGCC) flue gas (12 vol% O₂) and coal-fired flue gas, to verify its degradation resistance and operational stability under near-industrial conditions.
Laboratory results demonstrated that HNC-7 breaks the trade-off between mass transfer enhancement and viscosity deterioration widely observed in conventional absorbents. Thermodynamically, HNC-7 possessed a low absorption enthalpy of 66 kJ·mol^-1 and a high CO₂ cyclic capacity of 0.87 mol·kg^-1(@1.5kPa), indicating a remarkable potential to reduce regeneration energy consumption. In the 500-hour high-oxygen pilot test with NGCC flue gas, HNC-7 maintained a significantly higher main amine retention rate than the reference absorbent CESAR-1, and the addition of antioxidant further suppressed solvent degradation. Its stable capture performance and long-term operational reliability were also validated in the kiloton-scale coal-fired flue gas carbon capture pilot plant.
In conclusion, the novel HNC-7 absorbent integrates fast absorption kinetics, low regeneration energy demand and excellent oxidative degradation resistance. The pilot-scale verification confirmed its great feasibility for industrial deployment, providing an efficient and low-loss absorption solution for CO₂ capture from both gas-fired and coal-fired flue gases.
 

CO2 capture,molecular design,degradation,amine,pilot-scale evaluation