Production and characterization of water-steam activated carbons made from sugarcane bagasse and molasses pellets

Abstract

Pellets made from sugarcane bagasse and molasses in weight proportions 1.0:0.5 and 1.0:1.0 (wt%) were water-steam activated during 1, 2 and 4h, at 850°C, by two processes, namely, (1) pyrolysis and activation in two different assays or (2) pyrolysis and sequenced activation in a single experiment. All carbons showed basic characteristic, with approximately pH 10.5. Microporous texture was predominant with negligible macroporosity. Longer activation time provided a larger specific surface area with maximum BET 824.30 m2 g-1. In fact, the stage process was more effective than the sequenced one for the same activation time. Although pore size distribution (PSD) analysis showed pore size mode of approximately 1.50 nm, a second mode about 0.8 - 0.9 nm developed in over-two-hour activation periods in the stage process.