Synthesis of Activated Carbon and MCM-41 from Bagasse and Rice Husk and their Carbon Dioxide Adsorption Capacity

Abstract

The aims of this work were to synthesize the porous solid adsorbents and to study their carbon dioxide (CO₂) adsorption capacities. Three adsorbents; activated carbon synthesized from bagasse (BAC) and from rice husk (RAC), and Mobil Composition of Matter number 41 (MCM-41) from rice husk silica (R-MCM-41) were investigated. The synthesized BAC, RAC and R-MCM-41 showed high thermal stability with the weight loss less than 0.1% for the temperatures below 150°C. N₂ adsorption isotherm analysis indicates that BAC and RAC are microporous while R-MCM-41 is mesoporous materials. The BET surface areas were 923, 927 and 602 m² g-1 for BAC, RAC and R-MCM-41, respectively. The total pore volumes were 0.53, 0.56 and 0.49 cm³ g-1, and pore sizes were 0.8, 0.8, and 2.43 nm for BAC, RAC and R-MCM-41, respectively. At 30°C these materials were able to adsorb 76.89, 57.13 and 23.32 mg-CO₂ g-1-adsorbent, respectively. When the adsorption temperature increased, adsorption capacity of BAC, RAC and R-MCM-41 was decreased. This implied that physical process was the main mechanism of CO₂ adsorption.