ADSORPTION PROPERTIES AND MICROSTRUCTURE OF ACTIVATED CARBONS PRODUCED FROM AGRICULTURAL BY-PRODUCTS BY STEAM PYROLYSIS

A series of activated carbons has been prepared by steam pyrolysis of apricot and cherry stones, almond shells, and grape seeds at relativel y low temperatures of 600, 650, and 700-degrees-C for 1-3 h at each te mperature. The adsorption properties of the resulting activated carbon s were studied as a function of the treatment temperature, soak time, and nature of the precursor. Activated carbons produced from various a gricultural by-products showed different pore size distributions, depe nding on pyrolysis/activation conditions. Among the activation conditi ons used in this study, the treatment at 700-degrees-C for 2 h produce d the highest N2 BET surface area and pore volume obtained from each p recursor. The activated carbons were characterized by N2 adsorption, i odine, and methylene blue adsorption from solution. The microstructure s of the carbons were examined by optical and scanning electron micros copy. The adsorption characteristics of the activated carbons produced from various agricultural by-products were found to be different and strongly dependent on the composition and structure of the raw materia ls.