Utilization of activated carbons produced from some natural materials in the purification of used frying oil

The activated carbons (ACs) from shells of horse chestnut, chestnut, acorn, pistachio, apricot kernel, and wood shavings were evaluated to recover used oil (UO). The effects of the amount of AC, adsorption time, and temperature on the purification of the UO were investigated using the apricot kernel shells due to the high apricot production of Turkey. The kinetic evaluation was also done. The percentage improvements (PIs) in total polar materials (TPM), free fatty acids (FFA), p-anisidine value (p-AV), conjugated diene content (CD), and color of UO were found as 100, 56, 92, 51, and 90% for the apricot kernel AC in the column treatment. The most effective other ACs in decreasing FFA, p-AV, CD, and color were the horse chestnut (59%), chestnut (74%), chestnut (43%), and pistachio (72%), respectively. Consequently, these ACs can be used for the purification of UO. Practical applications Industrial wastes cause environmental pollution if they are ejected into river, sea, and soil. Therefore, they should be purified or treated for different purposes. In this study, the industrial wastes from the food and forest industries were used for the production of activated carbon to purify the used oil. The results showed that these activated carbons could be utilized for the regeneration of used oils. The most economical treatment is to blend the activated carbon with used frying oil for a certain time and remove it through centrifugation and filtration. The purified oil has the potential to be used in the biodiesel production.