Comparative study of preparation and characterization of activated carbon obtained from sugarcane bagasse and rice husk by using H3PO4 and ZnCl2

This research aim to prepare activated carbons from agricultural bio-waste materials by using chemical additives. In this study, activated carbons were synthesized by chemical activation of sugarcane bagasse and rice husk by using H3PO4 and ZnCl2. The sugarcane bagasse and rice husk was impregnated with ratio (raw precursor: activating agent) 1:1, 1:2 and 1:3. Activation was carried out at 600, 700, 800 and 900 °C in muffle furnace. Effect of different impregnation ratio, activation temperature and yield was studied and compared. As iodine number determination is the quick and easy indication of the internal surface area of activated carbon, hence, all the synthesized activated carbons were tested for iodine number and compared. The iodine number of the carbon made from sugarcane bagasse by using zinc chloride was 1140.69 mg/g for 1:2 ratio at 900 °C and with phosphoric acid iodine number found was 987.31 mg/g for 1:1 ratio at 900 °C. The carbon prepared from rice husk gives lesser iodine values and surface area as compared to sugarcane bagasse. The highest surface area of sugarcane bagasse made activated carbon impregnated with ZnCl2 found to be 1386.58 m2/g with pore volume of 0.9947. The optimum ratio was 1:2 with activation temperature of 900 °C. The rice husk gave maximum surface area 749.51 m2/g with ZnCl2. It has been observed from the results that, carbons prepared with zinc chloride gives maximum surface area than phosphoric acid. The characterization study, FTIR, SEM, BET, XRD and TGA-DTA of selected carbons were carried out and presented in the paper.