Regeneration by Induction Heating of Granular Activated Carbon Loaded with Volatile Organic Compounds

Abstract

Induction heating is used to regenerate granular activated carbon (GAC) for the purpose of recycling volatile organic compounds (especially solvents). As the technological possibilities offered by induction on an industrial scale have to be taken into account, the carbon has to be selected according to its origin and its granulometry.

Coconut charcoal (Picactif NC 60) with a median diameter of 3.8 mm was selected to maximize energizing yield. The incorporation of susceptors into the carbon (10% weight) significantly improved heating efficiency. For a current with frequency equal to 263 kHz, heating efficiency primarily depended on the granulometry of activated carbon and of suceptors. This current frequency also permitted a homogeneous heating of the GAG.

In addition, the adsorption capacity of activated carbon for removing ethyl acetate from waste water was evaluated. Once the parameters of the granular environment were maximized for both induction and adsorption in batch, cyclic adsorption-desorption experiments were conducted to evaluate regeneration adsorption capacity. An adsorption capacity value of 0.12 g/g was reached after the third adsorption-desorption cycle which represented a global loss in adsorption capacity of 32% compared to initial adsorption.

Experimental data indicate that industrial development of the induction heating process for GAC regeneration may be feasible.