Preparation Of Activated Carbon By Mechanochemical Process Using Different Activators

As an emerging discipline, The mechanical energy was brought into themechanochemical process by the ways of grinding or cutting, which led to the surfacebond of the reaction system breaks. Sequentially, unsaturated bonding, free electronions and lattice defects are produced, which leads to the increase in internal energy ofreactants and leave them in a unstable chemical activity state. As a result, theactivation energy of the reaction system decreases. The great crash force at collisionpoint generates instantaneous high temperature in the mechanochemical process,which contributes to the diffusion of the lattice defect and the rearrangement of atom.The mechanochemical process was applied to activated carbon prepared, in order tofull using the change of the substances reaction ability causing by mechanochemicaleffect, which led to woodiness material carbonization and activation, thus preparedhigh adsorption performance and better environmental compatibility activated carbon.In this paper, the activated carbons (ACS) were prepared by mechanochemicalprocess using potassium carbonate and potassium acetate as active reagent. Themethod of factor analysis and the Box-Behnken design were employed to investigatethe preparation factors(ball-milling time, ball-milling temperature, activation time,activation temperature and impregnation ratio),which effected the adsorptionproperties of iodine number and methylene blue of the ACS. The study had exploredthe optimal process conditions for preparing ACS by different activator. Theexperimental results: select potassium carbonate as the activator, for iodine number,the best condition was activation temperature800℃, ball-milling temperature180℃, activation time118min, ball-milling time19min, impregnation ratio143%,andfor methylene blue, the best condition was activation temperature800℃,ball-milling temperature180℃, activation time137min, ball-milling time20min,impregnation ratio138%; select potassium acetate as the activator, for iodine number,the best condition was activation temperature800℃, ball-milling temperature180℃, activation time124min, ball-milling time18min, impregnation ratio45%,and for methylene blue, the best condition was activation temperature800℃,ball-milling temperature180℃, activation time129min, ball-milling time19min,impregnation ratio49%.The pore structure and surface functional groups were studied by using FT-IR,automatic porosity and specific surface area analyzer and SEM. The infrared spectrashow two carbon material surface functional groups is similar. By the analysis ofFT-IR, two carbon materials have oxygen containing functional groups, such ashydroxyl, phonetic hydroxyl, and carboxyl and so on. With automatic porosity andspecific surface area analysis, the low temperature nitrogen adsorption isotherms ofactivated carbon preparation in different conditions using potassium carbonate andpotassium acetate as active reagent are type I, and the pore size are mainly to micporous,also contains a small amount of mesoporous, and the average pore radius respectively1.1and1.05nm.The SEM showed that the pore structure of PCACS and PAACS were regular.Studied have carried out for adsorption benzene vapor using the activatedcarbons activated by potassium carbonate and potassium acetate, and effected ofdifferent active reagent and ambient temperature. The resulted as fallow: kinetic ofbenzene vapor using the activated carbons prepared by mechanochemical processusing potassium carbonate and potassium acetate as active reagent imitated bypseudo-second-order, and correlation was higher than0.999, and the dynamicbehavior of adsorption benzene vapor using the activated carbons activated preparedwith different condition and ambient temperature was similar.