COMPARISON BEHAVIOUR OF COMMERCIAL ACTIVATED CARBON AND COAL-DERIVERED CHAR IN HOT SYNGAS CLEANING

This study aims at investigating and comparing the performances provided by a coal-derived char and a commercial activated carbon as catalysts for tar conversion. The char has been specifically produced in our facilities by steam activation of a Colombian coal's granulates, carried out at 900°C for 100 minutes. The activated carbon, named Norit RB4W, has been selected among those available on the market for utilization at temperature higher than 700°C. Naphthalene has been used as tar model compound. The influence of temperature (in the range 750-900°C) on the initial naphthalene conversion and the evolution of the naphthalene conversion with time at 750°C have been investigated. A correlation between the changes in the internal structure and the observed activity has been observed. In particular, for both the adsorbents the reduction of activity is associated to a decrease of the total specific pore surface.