Carbonization of the raw material, i.e. bare thermal activation
was conducted in a ceramic tube (10 cm i.d.) located in a horizontal
furnace (ENERGON HLT 18-50-14) electrically heated. Typically,
1 g of cork powder filled a ceramic capsule located in the tube
and was heated from room temperature to 750 C at 5 C min1
in a flow of N2 (100 cm3 min1, mass flow controlled) with no further
maintenance at that temperature