Continuous CO2 capture and methanation over Ni-Ca/Al2O3 dual functional materials

Although Ni-Ca-based dual functional materials (DFMs) have been examined for CO2 capture and reduction with H-2 (CCR) for the synthesis of CH4, their performance has generally been investigated using single reactors in an oxygen-free environment. In addition, continuous CCR operations have scarcely been investigated. In this study, continuous CCR for the production of CH4 was investigated using a double reactor system over Al2O3-supported Ni-Ca DFMs in the presence of O-2. We found that a high Ca loading (Ni(10)-Ca(30)/Al2O3, 10 wt% Ni, and 30 wt% CaO) was necessary for reaction efficiency under isothermal conditions at 450 degrees C. The optimized DFM exhibited an excellent performance (46% CO2 conversion, 45% CH4 yield, and 97% CH4 selectivity, respectively) and good stability over 24 h. The structure and CCR activity of Ni(10)-Ca(30)/Al2O3 were studied using X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectrometry (EDS), temperature-programmed desorption (TPD), and temperature-programmed surface reaction (TPSR) techniques.

Automated summary

Continuous CO2 capture and reduction for CH4 production was investigated using a double reactor system over Al2O3-supported Ni-Ca dual functional materials in the presence of O2. A high Ca loading (Ni(10)-Ca(30)/Al2O3) was found to be necessary for reaction efficiency. The optimized dual functional material showed excellent performance and stability.