Effect of Reaction Temperature on CO2 Capture Using Potassium-Based Solid Sorbent in Bubbling Fluidized-Bed Reactor

We investigated the effects of carbonation and regeneration temperature on the CO2 capture characteristics using SorbKX35, a potassium-based solid sorbent in a bubbling fluidized-bed reactor. A dry sorbent, SorbKX35 consists of K2CO3 for absorption and supporters for mechanical strength. We also measured the physical properties of the sorbent, such as pore size, pore volume, and surface area after carbonation or regeneration, to confirm the extent of the reaction. With H2O vapor pretreatment, nearly complete CO2 removal was initially achieved and maintained for about 10 min within a temperature range of 333.15-363.15 K with 2 s gas residence time. At lower temperature, CO2 capture was more effective during 1 h of carbonation. From the results of temperature programmed desorption and gas adsorption method (BET), we found that the regeneration of carbonated SorbKX35 was not complete at 473.15 K. The results obtained in this study can be used as basic data for designing and operating a large-scale CO2 capture process with two fluidized-bed reactors.