Morphological and structural evolution of activated carbons from almond shells

Almond shells represent an abundant agricultural waste which is annually produced in Sicily. Pyrolysis and gasification can be adopted to successfully modify its morphological and structural properties to produce graphitized porous material than can be used for environmental and energetical applications. The increase in pyrolysis and activation temperature led to pores formation and widening on the external surface as well as a re-organization of the internal structure toward a more graphitic one. Reaction temperatures tested were in the range of 600 °C to 1,000 °C, with 100 °C step increase, and the obtained material was characterized through SEM analysis. The samples prepared at 800 °C and 1,000 °C were further studied through TEM investigation. Aside from pore widening, as long as activation temperature was raised nano-onion carbon formations, characteristics or more graphitic structure were observed.