The combination of adsorbent slurry sorption with adsorbent electrochemical regeneration for VOC removal

A novel process for the removal of toluene from the gaseous phase at ppm levels has been designed, modelled and tested. The process combines toluene removal by three phase mass transfer in an aqueous adsorbent slurry with the electrochemical oxidation of the removed toluene and the regeneration of the adsorptive capacity of the adsorbent by this electrochemical process. The novel adsorbent, Nyex™, is a graphitic carbon with low surface area but is able to conduct electricity making it suitable for a system requiring rapid adsorption and adsorbent regeneration and re-use. It was demonstrated that the system could be described by a model based on physical mass transfer coupled with adsorption and the restoration of the adsorbent's adsorptive capacity. The model predicted an approximately 14% removal of inlet toluene and 12% removal during operation was observed. It was shown that the system's maximum removal capacity was based on the rate at which regenerated adsorbent could be added into the adsorption zone as long as sufficient charge had been passed through the adsorbent to restore its adsorptive capacity. © 2012 Elsevier B.V.