Production and characterization of activated carbon from horse chestnut kernel

Demirok, Tuğba
The production of activated carbon from horse chestnut kernel by chemical activation using phosphoric acid and characterization of produced activated carbons are presented in this work. To investigate effect of process parameters on porous structure of activated carbons, chemical activation was performed at the temperature of 300, 400, 500, 600, 700 and 800 ºC for impregnation ratios (weight of activation agent / weight g of sample) of 1:1 and 2:1. Chemical activation experiments were carried out in a quartz tube with diameter of 30 mm and length of 90 cm under a nitrogen flow of 100 cm3/min. To produce activated carbon, all the impregnated samples were heated to the desired activation temperature at heating rate of 10 ºC/min and were held at that temperature for activation time of 1 hour. Structural characterization of the obtained activated carbons was investigated by nitrogen gas adsorption analysis at 77 K. BET surface areas of activated carbons by horse chestnut kernel ranged between 9.7 and 862.4 m2/g. The highest BET surface area of 872.4 m2/g was attained for activated carbon which was produced with an impregnation ratio of 2:1 (weight of H3PO4 / weight of raw material), at activation temperature of 800 ºC at a yield of 21.7 %. The BET surface area of the activated carbon produced at 500 ºC for 2:1 impregnation ratio at a yield of 44.9 % was found as 713.4 m2/g. It was seen from the t plot analysis that activated carbon products have a microporous structure with a significant contribution of mesoporosity. It was seen that produced activated carbons have methylene blue numbers (MBN’s) varying between 2.7 and 49.9 mg/g. It was observed that the ratios of surface area covered by methylene blue to total surface area were small for activated carbon products except sample produced at 300°C and impregnation ratio of 1:1(weight of H3PO4 / weight of horse chestnut kernel). Nitrogen adsorption measurements and methylene blue experiments showed that produced activated carbons in present study are more suitable for gas phase applications due to the microporous structure of products. The results confirm that the properties of activated carbons depend on the impregnation ratio and chemical activation temperature. The results of the study show that the horse chestnut kernel can be used as raw material for preparation of activated carbon. .
Citation Formats
T. Demirok, “Production and characterization of activated carbon from horse chestnut kernel,” M.S. - Master of Science, Middle East Technical University, 2015.