Preparation of low cost activated carbons from various biomasses with microwave energy

Activated carbons are generated from various waste biomass sources such as waste tea, almond shells, tomato stems and leaves. Porous materials were prepared with phosphoric acids activation by microwave energy in a covered Teflon reactor for 1, 2, 3, and 4 min. The activated carbons were characterised in terms of surface area, pore size distribution, pore volume, FTIR analysis. The highest surface areas were obtained using almond shells (1,002 m(2)/g), waste tea (702 m(2)/g), tomato stems (813 m(2)/g) and tomato leaves (117 m(2)/g), respectively. The type of the raw material has significant effects on the characteristics of the final product. It was shown that porous carbons with high surface area could be prepared by short microwave radiation periods such as 2-3 min.