Investigation and comparison of carbon dioxide adsorption and fluidity behavior of activated carbon and titanium oxyhydroxide adsorbents

This study examined and compared the adsorption behavior and fluidity of two common adsorbents: activated carbon made from jujube seeds and titanium oxyhydroxide (TiO(OH)2) used in carbon dioxide capture. The activated carbon was produced through chemical activation with potassium hydroxide as the activating agent at a 2:1 weight ratio to the biomass. To assess the characteristics of the adsorbents, techniques such as SEM, BET, FTIR, and TGA were employed. The carbon dioxide adsorption capacity was tested at 25 and 50 °C. Regeneration was performed at 120 °C with a gas flow rate of 50 cm³/min. Adsorption was conducted for 1 hour, and desorption for 30 minutes, using 10% and 90% carbon dioxide concentrations in equilibrium with nitrogen. Results indicated that activated carbon had a significantly higher carbon dioxide adsorption capacity than TiO(OH)2 under the same conditions. To evaluate the fluidity of the different adsorbents, a gas-solid fluidized bed apparatus was used. Adding 5% by weight of hydrophobic silica nanoparticles to the adsorbents improved fluidity and increased bed expansion, due to reduced cohesive interactions between particles. The comparison of results highlights the considerable effectiveness of activated carbon as an efficient adsorbent for carbon dioxide capture.