A review on activated coke for removing flue gas pollutants (SO2, NOx, Hg0, and VOCs): Preparation, activation, modification, and engineering applications

A significant amount of flue gas pollutants (SO2, NOx, Hg0, and VOCs) are produced with the growth of human industrial activities including thermal power generation and iron and steel metallurgy. Activated coke is a low-cost, high-efficiency adsorbent for the removal of pollutants. It is the foundational component of dry flue gas purification technology and is easily recycled. The preparation, activation, modification, and engineering applications of activated coke are discussed in this paper. The removal mechanism of SO2, NOx, Hg0, and VOCs on activated coke is also summarized, along with the related factors affecting the adsorption performance of activated coke. This review demonstrates that physical activation, chemical activation, and a variety of modification techniques (such as metal loading) can improve the surface pore structure, increase the number of active sites on the surface, and introduce new functional groups, thereby improving the ability to remove pollutants. Additionally, the impact of the adsorption conditions (gas composition, adsorption temperature) on the ability of the activated coke to remove pollutants is extensively covered in this work. Some examples of practical applications of activated coke are listed. This review will serve as a roadmap for future research and application of activated coke.