MATHEMATICAL MODELING OF A NON-CATALYTIC GAS-SOLID REACTION: HEMATITE PELLET REDUCTION WITH SYNGAS

A mathematical model is developed to investigate the nonisothermal reduction of the hematite pellet with Syngas, namely is a mixture of hydrogen, water vapour, carbon dioxide and carbon monoxide gases. This model is based upon special application of the grain model and contains the interactions between Syngas and the hematite pellet as a re ection of the heat and mass transfer phenomena. Each grain is reduced as an un-reacted shrinking core model at three interfaces simultaneously. A concluded set of equations is solved using the nite volume approach as an implicit formulation. Finally, the model was applied to study the isothermal and non-isothermal reduction of the hematite pellet and investigate the eects of Syngas characteristics, like gas utility ((CO+H2)/(CO2+H2O)) and gas ratio (H2/CO), on the rate of reduction.