Calcium looping of CO2 capture coupled to syngas production using Ni-CaO-based dual functional material

Abstract

Calcium looping (CaL), which involves carbonation of CaO by CO2 and regeneration of CaO through the conversion of the captured CO2 into useful products, shows promise for carbon capture and utilization. By integrating CaL with methane dry reforming (DRM), the captured CO2 can be converted into syngas, a valuable chemical feedstock and fuel. Herein, a dual functional material (DFM) composed of CaO (CO2 adsorbent), Ni (DRM catalyst) and CeO2 (promoter for DRM) had been developed to drive the CaL-DRM tandem processes. The CaO-Ni-CeO2 DFM possessed high performance of cyclic CaL-DRM: high CO2 uptake efficiency (10.3 mmolCO2/gCaO), high H2 and CO yields (754.4 mmolH2/gNi and 454.6 mmolCO/gNi), moderate required temperature for carbonation (450 °C) and subsequent methane dry reforming (680 °C), and sufficiently high stability. The carbonation of CaO was strongly influenced by the basicity of the material, and the conversion of CH4 with the captured CO2 was affected by the Ni dispersion in the material. Overall, our work demonstrates a prototype study of using a temperature-programmed reaction platform for a quantitative, real-time analysis on CaL-DRM kinetics. The mechanistic understanding of CaL-DRM by the CaO-Ni-CeO2 DFM were elucidated, showing promise for the catalyst optimizations.