Activated Carbon Made from Tobacco Stalk with CO 2 Activation and its Pore Characterization

Abstract

In order to make use of tobacco stalk,activated carbon was prepared from tobacco stalk with carbon dioxide as activator.Effects of CO2 flux,activation time and temperature on the yield and adsorption property of activated carbon were studied with orthogonal experimentation.The proper conditions were: 800℃,30 min,CO2 flux: 3L/min,and the yield was 9.47%.The product's sorption values for iodine and methylene blue were 1079.26mg/g and 67.5mg/g,respectively.The nitrogen adsorption isothermal curve of the activated carbon was determined and its pore structure was characterized with BET method,H-K equation,D-A equation and theory of density function.The results showed that the obtained activated carbon was of micropore type with BET specific surface area of 761m2/g,total pore volume of 0.3521cm3/g.Of the total pore volume,micropores' volume accounted for 95.54%,mesopores' volume 3.85% and macropores' volume 0.61%.The microstructure of the activated carbon was analyzed by electronic microprobe and transmission electronic microscopy,the results were comparable with that determined by nitrogen adsorption.