PREPARATION OF ACTIVATED CARBON FROM LIGNIN OBTAINED BY STRAW PULPING BY KOH AND K2CO3 CHEMICAL ACTIVATION

摘要

Activated carbon was prepared through chemical activation of lignin from a straw pulping precursor, using K2CO3and KOH as chemical agents. To optimize the preparation method, the effect of the main process parameters (such as impregnation ratio, activation temperature and activation time) on the performance of the obtained activated carbon (expressed in terms of iodine number and yield of activated carbon) was investigated, and the actions of the activating agents were compared. The activated carbon prepared by K2CO3, under optimum conditions, permitted to obtain a BET surface area of 1104 m~2/g, including an external or non-microporous surface of 417 m~2/g, an average adsorption pore width of 2.0 nm, the amount of methylene blue, iodine number and the yield of activated carbon being of 10.6 mL/0.1 g, 1310 mg/g and 19.8%, respectively. As to the carbon activated by KOH under optimum conditions, its BET surface area was of 917 m~2/g, including the external or non-microporous surface of 231 m~2/g, the average adsorption pore width of 2.5 nm, while the amounts of methylene blue, iodine number and yield of activated carbon were of 9.6 mL/0.1 g, 1180 mg/g and 18.7%, respectively.