Production and characterization of KOH-activated carbon derived from polychlorinated biphenyl residue generated by the sodium dispersion process

Polychlorinated biphenyl (PCB) residues from the sodium dispersion (SD) process were employed as the raw materials for the production of activated carbon using KOH activation. The pore properties, such as the specific surface area and pore size distribution, were characterized using the Barrett–Joyner–Halenda method and the Horvath–Kawazoe method based on the N₂ adsorption isotherm at 77 K. The activated carbon produced showed similar adsorption capacities and specific surface areas to the commercially available product. The effects of the activation conditions on the porosity of the activated carbon produced were studied. The most significant factor affecting the specific surface proved to be the activation temperature. The activated carbon produced from PCB residues from the high-temperature (423–443 K) SD process had a binary pore size distribution well developed in the 4 nm region and in the micropore region. The pore structure of the carbon produced from PCB residues from the low-temperature (333–393 K) SD process had a wide range of micropores and mesopores.     

Pore structure and adsorption properties of activated carbon prepared from granular molded waste paper

We have previously manufactured activated carbon using waste paper board, which was prepared by adding 8% phenol resin adhesive to torn waste newspaper and hot-pressing. In this study, the pretreatment process of the raw material was simplified; the waste paper was extruded to form granules. The activated carbon was manufactured by the carbon dioxide activation method using the granules as the raw material. The properties of the activated carbon were evaluated based on the pore structure, the iodine adsorption number, and the adsorption of toluene vapor in a sealed chamber. The activated carbon, which was manufactured at an activation temperature of 1100°C and a treatment time of 60min, exhibited a specific surface area of 1241m²/g and an iodine adsorption number of 1120mg/g. These results were similar to those obtained for two commercially available activated carbons. The extent of toluene vapor adsorption by this activated carbon was similar to that observed for the two commercial activated carbons over a period of 130min.