Regeneration of catalysts deactivated by coke deposition: A review

In industrial catalytic processes, coke deposition can cause catalyst deactivation by covering acid sites and/or blocking pores. The regeneration of deactivated catalysts, thereby removing the coke and simultaneously restoring the catalytic activity, is highly desired. Despite various chemical reactions and methods are available to remove coke, developing reliable, efficient, and economic regeneration methods for catalytic processes still remains a challenge in industrial practice. In this paper, the current progress of regeneration methods such as oxidation (air, ozone and oxynitride), gasification (carbon dioxide and water steam), and hydrogenation (hydrogen) is reviewed, which hopefully can shed some light on the design and optimization of catalysts and the related processes.