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  • Publication
    Accès libre
    The effect of the carbonization/activation procedure on the microporous texture of the subsequent chars and active carbons
    Cagnon, Benoît
    Py, Xavier
    Guillot, André
    Chars obtained by carbonizing coconut shells at different intermediate heat treatment temperatures (IHTT) between 400 and 800 °C were activated at 800 °C in a stream of N2+H2O, following two distinct procedures. In the first procedure, activation follows directly the carbonization, whereas in the second procedure, the sample was first brought back to 25 °C and subsequently heated again to the activation temperature of 800 °C. The data for CO2 adsorption at 25 °C and N2 at −196 °C with immersion calorimetry confirms that the activated carbons derived from chars obtained at low IHTT and in two steps, present a “gate effect” for burn-offs <20% or 25%, otherwise, the final carbons present similar structural characteristics for higher burn-offs. It also appears that the evolution of the average pore width L0 with the micropore volume W0 follows a general pattern outlined early.