Screening of Spray-Dried K 2 CO 3 -Based Solid Sorbents using Various Support Materials for CO 2 Capture

K2CO3-based dry regenerable sorbents were prepared by spray-drying techniques to improve mass produced K2CO3-Al2O3 sorbents (KEP-CO2P, hereafter), and then tested for their CO2 sorption capacity by a 2,000 Nm 3 /h (0.5 MWe) CO2 capture pilot plant built for Unit 3 of the Hadong thermal power station in 2010. Each of the sample sorbents contained 35 wt.% K2CO3 as the active materials with various support materials such as TiO2, MgO, Zeolite 13X, Al2O3, SiO2 and hydrotalcite (HTC). Their physical properties and reactivity were tested to evaluate their applicability to a fluidized-bed or fast transport-bed CO2 capture process. The CO2 sorption capacity and percentage utilization of K2CO3-MgO based sorbent, Sorb-KM2, was 8.6 g-CO2/100 g-sorbents and 90%, respectively, along with good mechanical strength for fluidized-bed application. Sorbs-KM2 and KT were almost completely regenerated at 140°C. No degradation of Sorb-KM by SO2 added as a pollutant in flue gas was observed during a cycle test.