A Mathematical Model for Moving–Bed Reactors with Multiple Chemical Reactions

A general model is developed for moving–bed reactors where multiple noncatalytic gas–solid reactions and multiple gas phase reactions take place. An industrial moving–bed reactor for direct reduction of Fe2O3 pellets is selected as the case study. The grain model is modified as the kinetics model in the case of multiple non–catalytic gas–solid reactions. The kinetics model provides the knowledge of local degree of the origin solid reactant along with the intermediate solids within the porous pellets. The heat transfer by convection, conduction and radiation in the gas bulk and the radial temperature distribution of the pellet is considered. The proposed model well simulates the experimental data with an average error of 4.6%.

Keywords:

Moving–bed , Gas–solid reactions , Multiple reactions , Hematite , Kinetics