Simulation of a bubbling fluidized bed process for capturing CO2 from flue gas

We simulated a bubbling bed process capturing CO2 from flue gas. It applied for a laboratory scale process to investigate effects of operating parameters on capture efficiency. The adsorber temperature had a stronger effect than the regenerator temperature. The effect of regenerator temperature was minor for high adsorber temperature. The effect of regenerator temperature decreased to level off for the temperature >250 °C. The capture efficiency was rather dominated by the adsorption reaction than the regeneration reaction. The effect of gas velocity was as appreciable as that of adsorber temperature. The capture efficiency increased with the solids circulation rate since it was ruled by the molar ratio of K to CO2 for solids circulation smaller than the minimum required one (Gs, min). However, it leveled off for solids circulation rate >Gs, min. As the ratio of adsorber solids inventory to the total solids inventory (xw1) increased, the capture efficiency increased until xw1=0.705, but decreased for xw1>0.705 because the regeneration time decreased too small. It revealed that the regeneration reaction was faster than the adsorption reaction. Increase of total solids inventory is a good way to get further increase in capture efficiency.