Production and characterization of activated carbon from sour cherry stones by zinc chloride

The purpose of this study is to produce the low-cost activated carbon from the sour cherry (Prunus cerasus L.) stones, known as a waste of fruit juice industry, by chemical activation using zinc chloride. The effects of the activation temperature and the impregnation ratio on the surface and chemical properties of activated carbon were investigated. Also, the mathematical correlation between the activation process variables and outputs such as activated carbon yield and surface area were examined by using the Response surface methodology. The activation temperatures and impregnation ratios were selected at the range of 500–900 °C and 1:1–4:1, respectively. In the study, it was observed that the optimum conditions for the activated carbon production were activation temperature of 700 °C and impregnation ratio of 3:1. The optimum conditions resulted in an activated carbon with a carbon content of 80.78% and a yield of 16.22%, while the Brunauer–Emmett–Teller surface area evaluated using nitrogen adsorption isotherm corresponds to 1704 m2 g−1, with the total pore volume of 1.566 cm3 g−1. The activated carbon was heteroporous with the micropore volume contributing to 62.84%. Also, experimental results showed that the activation temperature and the impregnation ratio have significant effects on the pore structure of the activated carbon and sour cherry stones seemed to be an alternative precursor for the commercial activated carbon productions.