Infrared Thermal Regeneration of Spent Activated Carbon from Water Reclamation

An infrared conveyor-belt furnace was evaluated and utilized to conduct a parametric study on the effects of temperature and residence time on spent granular carbon intraparticle structure and concomitant regeneration efficiencies, incorporating an appraisal of the efficacy of low-temperature long-residence-time regeneration conditions. In addition, a virgin carbon of the same type and particle size fraction as was used in the above regeneration study, was subjected to equivalent temperature and residence time conditions to serve as a control experiment designed to shed light on the effects of regeneration conditions on the activated carbon per se. The infrared furnace proved to be an effective system for the regeneration of spent carbon; and an optimum operating region of 800 °C/10 min to 850 °C/5 min was identified. Temperatures in excess of 850 °C, regardless of residence time, must be avoided since excessive structural and pore volume distribution degradation is effected.