The design is based on the knowledge acquired in previous
studies in the physical activation of the char obtained in the pyrolysis
of waste tyres, and a scheme of the plant used is reported
elsewhere (Lopez et al., 2009b). The activation occurs in a fixed
bed reactor placed inside a radiant oven that provides heat to operate
at temperatures up to 1000 C. The unit is provided with a pressure
meter to ensure that pressure in the reactor is not above
1.2 atm during the activation. Both the reactor and the oven are
located in a forced convection oven (hot box), and kept at 270 C
in order to ensure the complete vaporization of the water fed into
the reactor to perform steam activation. Nitrogen and carbon dioxide
(in case the latter is used as activating agent) are fed into the
reactor by means of two mass flowmeters. Water flowrate is controlled
by a high precision Gilson 307 pump, and a heating coil
with an electric cartridge is located at the inlet of the hot box in
order to ensure the immediate and homogeneous vaporization of
the water stream. Finally, the non-reacted steam was condensed
at the outlet of the reactor in a Peltier cooler.