Enhancement in CO2 Adsorption on Hydrotalcite-based Material by Novel Carbon Support Combined with K2CO3 Impregnation

In recent years, a great deal of interest has been shown for high-temperature adsorption of CO, on hydrotalcite-like compounds (HTlcs). Numerous efforts have been undertaken to enhance the CO, capture property of HTlcs, including alkali-metal impregnation, use of support materials, and modification of chemical composition. The present work demonstrates the applicability of coal-derived graphitic material (CGM) as an effective support for neat as well as K2CO3-promoted Mg-Al HTlc, enhancing the CO, adsorption capacity. Both surface area and basic site density affect the adsorption capacity. The K2CO3-promoted CGM-supported Mg-Al HTlc exhibited a fresh adsorption capacity of 1.10 mmol g(-1) at 300 degrees C under a total pressure of 1 bar. After the initial drop, it maintained an average working capacity of 0.42 mmol g(-1) during nine cycles of adsorption desorption in the temperature range of 300-400 degrees C. The Yoon-Nelson kinetic model fit well with the experimental data.