CFD simulation of CO2 sorption on K2CO3 solid sorbent in novel high flux circulating-turbulent fluidized bed riser: Parametric statistical experimental design study

•Circulating-turbulent fluidization was proved to be advantage on CO2 sorption.•The novel regime was proven to capture CO2 higher than the conventional regimes.•Uniform solid particle distribution was observed in the novel fluidization regime.•The system continuity had more effect in the system than the process system mixing.•Parametric experimental design analysis was studied to evaluate significant factor.

In this study a high flux circulating-turbulent fluidized bed (CTFB) riser was confirmed to be advantageous for carbon dioxide (CO2) sorption on a potassium carbonate solid sorbent. The effect of various parameters on the CO2 removal level was evaluated using a statistical experimental design. The most appropriate fluidization regime was found to occur between the turbulent and fast fluidization regimes, which was shown to capture CO2 more efficiently than conventional fluidization regimes. The highest CO2 sorption level was 93.4% under optimized CTFB operating conditions. The important parameters for CO2 capture were the inlet gas velocity and the interactions between the CO2 concentration and the inlet gas velocity and water vapor concentration. The CTFB regime had a high and uniform solid particle distribution in both the axial and radial system directions and could transport the solid sorbent to the regeneration reactor. In addition, the process system continuity had a stronger effect on the CO2 removal level in the system than the process system mixing.