Preparation of Activated Carbons from Waste Coffee Beans

Abstract

Activated carbons were prepared from waste coffee beans by conventional steam activation. Obtained activated carbons were evaluated from a viewpoint of porous properties. It was shown that prepared activated carbons had around 900m²/g of BET surface area and about 0.3 cm³/g of mesopore volume. The effect of the pretreatment was also investigated for the further development of porous properties. Here, the pretreatment means mixture of metal salts with raw materials and acid treatments prior to the steam activation. It was observed that mesopores of activated carbon prepared via mixture of Ca (OH) ₂, carbonization, HNO₃ treatment at boiling point and steam activation were much developed. The carbons had over 1000m²/g of BET surface area and about 0.5 cm³/g of mesopore volume. It was indicated that the possibility of practical use of the activated carbons from waste coffee beans, because mesopores of carbons prepared via pretreatments were more developed than those of commercial activated carbon.