Study on the preparation of granular activated carbon from tobacco stems activation by steam

A series of granular activated carbons were prepared, using tobacco stems as materials, wood tar as the mainly binder and steam as the activation agent. The effect of process variables such as activation temperature, activation time and flow rate of steam on yield and adsorption properties was systematically studied. The optimum preparation parameters were obtained as follows: activation temperature was 900°C, activation time was 60 minutes and flow rate of steam was 3.31g/min. The yield of the granular activated carbon was 24.39% when the methylene blue adsorption reached 285mg/g and the iodine number was 1028mg/g. Furthermore, the granular activated carbon in optimum condition was characterized by N2 adsorption at 77K, using the BET and DFT methods. The BET surface area and pore volume were 1073m2/g and 0.8152mL/g, respectively. It shown that the granular activated carbon possessed predominant microporous structures.