Sulfation rates of cycled CaO particles in the carbonator of a Ca-looping cycle for postcombustion CO2 capture

摘要

[EN] Calcium looping is an energy-efficient CO2 capture technology that uses CaO as a regenerable\udsorbent. One of the advantages of Ca looping compared with other post-combustion technologies\udis the possibility of operating with flue gases that have a high SO2 content. However,\udexperimental information on sulfation reaction rates of cycled particles in the conditions typical\udof a carbonator reactor is scarce. This works aims to define a semi-empirical sulfation reaction\udmodel at particle level suitable for such reaction conditions. The pore blocking mechanism\udtypically observed during the sulfation reaction of fresh calcined limestones is not observed in\udthe case of highly cycled sorbents (N>20) and the low values of sulfation conversion\udcharacteristic of the sorbent in the Ca-looping system. The random pore model is able to predict\udreasonably well the CaO conversion to CaSO4 taking into account the evolution of the pore\udstructure during the calcination/carbonation cycles. The intrinsic reaction parameters derived for\udchemical and diffusion controlled regimes are in agreement with those found in the literature for\udsulfation in other systems