The Study Of Preparation And Adsorption Properity On Porous Block Carbon Materials

The porous block carbons with good mechanical and adsorption properties were successfully prepared through two kinds of methods. .The influence of the preparation methods and conditions on pore structure and properties of porous block carbons were investigated. The various adsorption properties of prepared samples were tested as well.Porous block carbons were successfully prepared using green petroleum coke as main raw material with the process of being milled, molded, carbonized and activated. Green petroleum coke which contains less ash content and higher volatile content was chosen as raw material, while KHCO3 was used as main chemical activation reagent. The porous block carbon was prepared successfully when the molding pressure was 15MPa, the ratio of KHCO₃ to green petroleum coke was 4, the weight ratio of coal tar pitch was 10%, chemical activation temperature was 950℃and preserved for 60min, heating rate was 2℃/min, physical activation temperature and time were 800℃and 60min. The BET surface area, total pore volume, benzene adsorption, iodine adsorption, methylene blue adsorption and compression strength of porous block carbon is 1403.56 m²/g, 0.6024 ml/g, 82.7%, 1545.8mg/g, 896.9mg/g and 4.7MPa respectively. In order to improve the adsorption properties of porous block carbon, the pore size of porous block carbon was modified. The benzene adsorption of the porous block carbon could come to 86.7% when the concentration of impregnant was 60% and the sample was dipped once, while iodine adsorption and methylene blue adsorption could come to 1703mg/g and 987mg/g respectively when the concentration of impregnant was 60% and the sample was dipped twice.Porous block carbons were successfully prepared using homemade porous powdery carbons with excellent adsorption properties as main raw materials, with the process of being molded, solidified and heat treatment. The porous powdery carbons, with BET surface area of 2154.36m²/g, total pore volume of 1.0958ml/g, benzene adsorption of 115.7%, iodine adsorption of 2246mg/g, and methylene blue adsorption of 1136.7mg/g, were prepared successfully when KOH was added as chemical active reagent, chemical active temperature was 800℃and preserved for 1.5h, heating rate was 4℃/min, physical active temperature and time was 750℃and 60min. Using homemade porous powdery carbons as main raw materials, carboxymethyl cellulose （CMC） as adhesive, porous block carbons were successfully prepared after being molded at 15MPa, heated at 250℃for 90 min, the porous block carbon was successfully prepared. The BET surface area, total pore volume, benzene adsorption, iodine adsorption, methylene blue adsorption and compression strength of porous block carbon is 1647.44m²/g, 0.7974ml/g, 84.2%, 1365.0mg/g, 889mg/g and 13.5MPa respectively.The cycling property of absorption-desorption for toluene vapor of the porous block carbon, the electrothermal behavior of the porous block carbon applied to vapor desorption and the adsorption property of porous block carbon for water containing dyestuff were investigated. The results show that the cycling property of absorption-desorption of the porous block carbons for toluene vapor is good, the adsorption of the porous block carbons prepared from porous powdery carbons for toluene vapor is better than that prepared from green petroleum coke. And the adsorption effects for methyl orange and Congo red are obvious. It takes 3 hours for adsorption coming into saturation. The adsorption property of the porous block carbons prepared from green petroleum coke for methyl orange and Congo red is better than that prepared from porous powdery carbons.The nitrogen adsorption/desorption property of this two kinds of porous block carbons prepared from green petroleum coke and porous powdery carbon were compared with that of the porous block active carbon on sale. The result show that, under the same condition, the nitrogen adsorption/desorption of the two kinds of homemade porous block carbons are 2.7 and 3 times as that of porous block active carbon on sale.