Preparation and textural characterisation of activated carbon from vine shoots (Vitis vinifera) by H3PO4 -: Chemical activation

An abundant and low-cost agricultural waste as vine shoots (Vitis vinifera) (VS), which is generated by the annual pruning of vineyards, has been used as raw material in the preparation of powder activated carbon (AC) by the method of chemical activation with phosphoric acid. After size reduction, VS were impregnated for 2 h with 60 wt.% H3PO4 solution at room temperature, 50 and 85 degrees C. The three impregnated products were carbonised at 400 degrees C. The product impregnated at 50 degrees C was heated either first at 150-250 degrees C and then at 400 degrees C or simply at 350-550 degrees C in N-2 atmosphere. The time of isothermal treatment after each dynamic heating was 2 h. The carbons were texturally characterised by gas adsorption (N-2, -196 degrees C), mercury porosimetry, and density measurements. FT-IR spectroscopy was also applied. Better developments of surface area and microporosity are obtained when the impregnation of VS with the H3PO4 solution is effected at 50 degrees C and for the products heated isothermally at 200 and 450 degrees C. The mesopore volume is also usually higher for the products impregnated and heated at intermediate temperatures. (c) 2005 Elsevier B.V. All rights reserved.