Numerical and Experimental Research on Chemical Looping Pyrolysis of Coal Tar in a Fluidized Bed Reactor

Abstract

Simulation and experiment were carried out as a validation methodology to study the chemical looping pyrolysis of coal tar to prepare carbon black (CB) in a fluidized bed reactor. The results demonstrate that Fe2O3 is reduced to FeO, Fe3O4, and a limited amount of Fe after the Fe-based oxygen carrier (OC) reacted with the coal tar. The gas products mainly consisted of H2 and CO, and transmission electron microscopy shows that the particle sizes of CB were in decent agreement with the simulation and the size of a single carbon sphere was approximately 40 nm. There were regular changes of the OC particle sizes during the redox process, and the OC particle size was reducing when the oxygen was releasing and was increasing when the oxygen was gaining. Therefore, the OC particle size variation contributes a suitable method to characterize the evolution of the oxygen carrying capacity. The simulations reveal the mechanisms of the chemical looping pyrolysis of coal tar with the reaction models.