Circulating Fluid-Bed Studies for CO2 Capture from Flue Gas using K2CO3/Al2O3 Adsorbent

Recent research has concentrated on the adsorption-based CO2 capture process with dry regenerable adsorbents that follows carbonate–bicarbonate chemistry in a thermal-swing mode. The potential advantages of solid adsorbents for CO2 capture were assessed on a pilot scale. The performance of 35 wt % K2CO3 supported on alumina was investigated in both batch (non-circulating) and continuous operation with adsorbent circulation mode. The effect of various parameters, such as adsorption and desorption temperatures, water vapor content in the flue gas stream, gas-hourly space velocity, mode of adsorbent regeneration, etc., were investigated in the system comprised of bubbling fluidized-bed adsorber and desorber. It has been found that the formation of hydrated species of K2CO3 during the desorption process in turn facilitates the CO2 adsorption reaction in the adsorber. The overall energy demand seems to be reduced during partial regeneration of the adsorbent, as against the requirement of 141 kJ/mol for full re...