Abstract:

Using carbon by-products produced by bamboo gasification as raw material and the polymerized modified tar as the binder, the bamboo formed activated carbon was obtained by hydro-forming, pyrolytic cross-linking and followed by water vapor activation. The forming mechanism of different binders were analyzed, and the properties of activated carbon were investigated, such as the variety of the binder, the adding amount of modified tar, the activation temperature and the activation time. The results showed that after modification by aromatization and cross-linking, the molecular weight and thermal stability of tar were improved; the blocking effect of bamboo char pore channels was reduced; the bonding and pyrolytic cross-linking between char particles were enhanced; and high-performance bamboo forming activated carbon could be prepared. Using 40g bamboo charcoal as raw material, the tar addition amount of 12 g, the carbonization temperature of 550 ℃, the carbonization time of 90 min, the activation temperature of 850 ℃ and the activation time of 80 min, the iodine adsorption value of the formed carbon was 1 232 mg/g, the methylene blue(MB) adsorption value was 240 mg/g, the strength was 91%, and the yield was 48.5%. The specific surface area and total pore volume were 1 157 m²/g and 0.478 1 cm³, respectively. The adsorption rates of toluene and carbon tetrechloride were 385 mg/g and 75.2%, respectively. And the adsorption rate of toluene and carbon tetrechloride was positively related to the micropore volume of formed activated carbon.

Key words: formed activated carbon, modified tar, binder, micropore volume, gas phase adsorption