Activated carbon from some agricultural wastes under action of one-step steam pyrolysis

A one-step steam pyrolysis scheme was applied, in the range 600-700 degrees C, for the production of activated carbons from five lignocellulosic mater ials. The products were characterized by N-2/77 K adsorption for evaluating their surface area and pore volume. Simple carbonization at 700 C resulted in poor adsorbing carbons whereas porosity was remarkably enhanced under a ction of steam. Carbon precursors derived from date palm wastes (branches, leaves and date pits) proved feasible raw materials that produced good adso rbing carbons. Rice husks and barbecue charcoal developed porosity to a low er extent, due to the inherent ash content. All obtained carbons were essen tially microporous due to the limited gasification. Steam is suggested to p lay a double role: it promotes both the release of volatiles with partial d evolatalization, and enhances carbon formation.