Phosphoric Acid Activation of Agricultural Residues and Bagasse

J. BLANCO CASTRO; P. R. BONELLI; E. G. CERRELLA; A. L. CUKIERMAN

INDUSTRIAL & ENGINEERING CHEMICAL RESEARCH

AMERICAN CHEMICAL SOCIETY

Lugar: COLUMBUS, OH., USA; Año: 2000 vol. 39 p. 4166 - 4172

0888-5885

Activated carbons from two different types of sugar cane wastes, agricultural residues and bagasse, were prepared by phosphoric acid activation varying the carbonization temperature (300-600 °C), the weight ratio of phosphoric acid to precursor (R ) 1-2.5), and carbonization time (0-3 h). Surface properties of the resulting carbons were markedly dependent on the precursor and a combined effect of the conditions employed. Bagasse carbons showed higher surface area and pore volume than those from agricultural residues. Maximum surface areas of around 1100 and 780 m2/g were respectively attained. Temperature above 500 °C, impregnation ratio higher than 2, or prolonged carbonization beyond 1 h led to reduction in porosity development. Selected carbons from both wastes with relatively large mean pore radius showed good ability to decolorize a diluted solution of synthetic melanoidin, used as a model of molasses wastewater. Iodine number between 608 and 746 and methylene blue uptake of 213-261 (mg/g) were determined for the selected samples.