Preparation of fibrous activated carbon(ACF) from commercial polyacrylonitrile(PAN) fibers was investigated in an effort to explore the possibility of reutilization of waste PAN fibers. Commercial PAN fiber samples were oxidized at 230℃ and 250℃ in air for 90 min . Thus obtained oxidized fibers were futher activated at 800℃, 900℃ and 1000℃, Activation behavior and activation yield were measured for each process. The final activated carbon fibers were subjected to examination of their adsorption capacity, fiber strength, average pore size.
The commercial PAN fibers were oxidized at faster rate compared with PAN precursors which are used to manufacture carbon fibers. At elevated temperature and longer time period the activation yield decreased. From the relation between activation time vs. yield, the reaction constant was obtained as 0.002 min-1, 0.033 min-1, 0.118 min-1 at 800℃, 900℃, 1000℃ respectively. This value is higher than those of charcoals which are used as raw material for the powdered activated carbon. With higher activation temperature and increased time, the value of $I_2$ adsorption and methylene blue decoloration, BET specific surface area increased.
As expected, the Fiber strength, however, decreased to 58 MPa, much lower than that of commercial ACF(271 MPa).
