Because it is the most promising method for reforming tar in a gasification system, a catalytic steam reforming reaction of tar using a dyeing sludge ash catalyst that contains mostly iron oxide has been modeled using benzene to investigate whether a steam reforming catalyst produced from waste is viable. The catalytic activity of the ash catalyst is similar to that of the commercially available iron-chrome-based catalyst for the same equivalent total amount of Fe2O3. The activity over the ash catalyst has been examined in terms of the weight hour space velocity (WHSV) and the reaction temperature to develop a model for the reaction kinetics. Using a power law model, the reaction order coefficients of the benzene and steam were estimated to be 0.43 and 0, respectively. The activation energy required for the ash catalyst was approximately 187.6 kJ mol.1. In addition, the reductive properties of the iron oxide in the ash catalyst were also examined via XRD and H2-TPR analyses.