Impregnated Palm Kernel Shell Activated Carbon for CO2 Adsorption by Pressure Swing Adsorption

Objectives: To study the application of impregnated palm kernel shell activated carbon (AC-PKS) as carbon dioxide (CO2) adsorbent for simulated coal-fired power flue gas. Methods/Statistical Analysis: The activated carbon was prepared using chemical (ZnCl2) activation method and impregnated with several types of metal oxides (Cerium, Barium and Titanium). The physico-chemical properties of PKS-ACs such as BET surface area, pore volume, and pore diameter were performed using N2 adsorption isotherm. Both loaded and unloaded ACs were also characterized using X-ray diffraction (XRD) and Scanning electron microscopy (SEM). The adsorption of CO2 from the simulated flue gas was investigated by pressure swing adsorption process in fixed-bed reactor. Findings: AC-PKS impregnated with Cerium Oxide (CeO2) showed the highest sorption capacity of CO2 among other impregnated metal oxides. AC-PKS/CeO2 also displayed the longest breakthrough time of 350 seconds for CO2 with 0.63 mole CO2/kg AC. The CO2 adsorption capacity of AC-PKS, ACPKS- TiO2, PKS-AC/BaO and AC-PKS/CeO2 until complete saturation, were at 0.54 mole CO2/kg AC, 0.78 mole CO2/kg AC, 1.37 mole CO2/kg AC and 1.41 mole CO2/kg AC, respectively. During the desorption process, 99% of CO2 can be recovered and under 2 bar, 3 bar and 4 bar, the purity of CO2 was 25%, 36% and 38%. Interestingly, the purity increased to 93% when purging step with CO2 was added. Application/Improvements: This system will be implemented to capture CO2 from flue gas emissions from coal based power plant.