Abstract
Porosity variation of activated carbons, prepared under different activation times and CO 2 flows, is provided. Cellulose fibers of Eucalyptus saligna (Myrtaceae) wood were first pyrolysed in N 2 with a heating rate of 5oC min -1 , up to 800oC. Samples were then activated at 850oC, in CO 2 flows of 15 to 120 mL min -1 , during 1, 2 and 3 hours. Porosity of carbons was characterized by determining the burn-off grades of activated cellulose fibers, the specific surface areas S BET of the pores, the average radius of gyration of micropores R g and the meso/macropores K/Q 0 Porod relations. Concomitant increase of CO 2 flow and activation time induced burn-off increase and micropores Rg reduction. However, improvement of S BET areas allows the authors to conclude that smaller size micropores were created in larger amounts. Under the same conditions, increases of K/Q 0 indicated a sensitive creation of macropores and/or the mesopores coalescence
Published Version
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