Effect of char structures caused by varying the amount of FeCl3 on the pore development during activation

Abstract

A series of Fe-loaded coal chars is obtained by varying the load amount of FeCl₃ additives (0, 6, 15 and 30 wt%). The effect of FeCl₃ on the char structure during pyrolysis is presented; furthermore, the chars with different typical structures are activated under different burn-offs to study the pore development during activation. The results show that the mesopore size distribution is related to the amount of FeCl₃. A small amount of FeCl₃ additive (6 and 15 wt%) can promote depolymerization of the aromatic structure and formation of well-developed spatial crosslinks, and a greater amount of FeCl₃ additive (30 wt%) can accelerate the graphitization tendency. The pore formation of 0Fe-900 without initial mesopores follows a hierarchical development from the surface to the core. The chars 15Fe-900H, 15Fe-900H and 30Fe-900H with some initial mesopores follows a non-hierarchical development from the external and internal particles simultaneously; however, the difference in microstructure can affect the penetration of the activated agent into the particle, resulting in different burn-offs and external carbon losses when the hierarchical porous structure has been produced.