Integrating Calcium-Looping and Reverse-Water-Gas-Shift Reaction for Co2 Capture and Conversion: Screening of Optimum Catalyst

Abstract

Integrating calcium-looping cycle (CaL) with reverse-water-gas-shift (RWGS) reaction represents an effective path to realizing integrated CO2 capture and utilization (ICCU). Screening a suitable catalyst to construct highly efficient CaO-based dual function materials (DFMs) is essential for CaL-RWGS. In the current work, M@CaO (M=Ni, Co, Mn and Fe) DFMs are prepared for ICCU-RWGS, and the influence of catalyst component on the structure, CO2 capture and RWGS performance and kinetic behaviors of the CaO-based DFMs is investigated. Results indicate that the interaction between CaO and catalyst will affect the average grain size and dispersion of metallic catalyst, oxygen vacancy concentration, surface basicity and reducibility of the CaO-based DFMs. The desired Co@CaO DFMs shows excellent ICCU-RWGS performance under 650oC, 15%CO2 and 50%H2, with a high CO2 capture capacity of 13.0 mmol CO2/g, great CO yield of 4.78 mmol CO/g, 98%CO2 conversion and 90% CO selectivity. Besides, Co@CaO also exhibits preferable carbonation and regeneration kinetics and outstanding cyclic working stability, with no obvious loss in CO2 capture capacity and a low decay rate of 8% for CO production in 10 cycles. Co@CaO could be a preferred DFMs candidate for CaL-RWGS applications.

Keywords: Integrated CO2 capture and conversion, calcium-looping cycle, reverse-water-gas-shift reaction, dual function materials, metallic catalyst