Production and properties of porous carbon from bagasse of sugarcane grown in Brazil

The bagasse is the compressed waste of the sugarcane from Brazil and was found to have small holes of about 8x10(-7) m in diameter on its surface. By the carbonization under nitrogen gas, the bagasse changed to a porous char having the adsorption ability and the water content in the bagasse influenced its activation. The condition of the carbonization was evaluated according to surface form, specific surface area and adsorption capacity of the char. The effect of water-content in the bagasse was also evaluated by the relationship of the product of char yield (Y) x specific surface area (S) and the char yield (Y). Our experimental results indicated that the small holes of the bagasse were increased with increasing heating temperature until 973 K. Under the conditions of heating rate of 10 K/min and heating temperature of 1273 K, specific surface area of the char was 611x10(3) m(2)/kg and the adsorption capacity was 960 x10(-3) kg/kg in iodine test and 52 x10(-3) m(3)/kg in Methylene Blue test. When the water content in the bagasse was 200% under the condition of the heating rate of 10 K/min until 1173 K or the heating rate of 5 K/min until 1273 K, the specific surface area was 967-1055 x 10(-3) m(2)/kg. Further study illustrated that the equilibrium adsorption isotherms of benzene steam by this char was the same as that of the bagasse activated carbon. It was possible to arrange our data by the Langmuir's equilibrium adsorption isotherm. By the carbonization of this water-containing bagasse under nitrogen gas, the adsorption mechanism of the resulting char became equal to that of the activated carbon.