CO2/NOx storage and reduction (CNSR) technology — a new concept for flue gas treatment

Abstract

The emission of CO2 and NOx from industrial factories poses significant challenges to human health and contributes to extreme climate change. NOx storage and reduction (NSR) and integrated CO2 capture and methanation (ICCM) technology are one of the effective technologies to deal with NOx and CO2, respectively. However, there is currently no relevant technology available for the simultaneous removal of both NOx and CO2 gases co-exist in flue gas. This paper proposes a new concept named CO2/NOx storage and reduction (CNSR) for the first time. This approach utilizes K-Pt/Ni3Al1Ox dual functional material (DFM) to achieve co-storage of CO2 and NOx, followed by their reduction to CH4 and N2, respectively. The CNSR tests demonstrate the feasibility of this technology. At 350 oC, the conversion for CO2 and NOx were 60.8% and 99.5%, with CH4 and N2 selectivity of 98.9% and 90.3%, respectively. After 10 cycles, the sample exhibited a relatively stable CO2 conversion of around 66%, with CH4 selectivity remaining above 90%. The conversion of NOx remained essentially unchanged at close to 100%. Furthermore, the possible mechanism for CNSR process was proposed in this study. We believe that this work will provide a novel strategy for the treatment of multi-component gaseous pollutants in flue gas.