Reaction kinetics of H2O and CO2 with molten slag containing FeO for H2-CO gas production

As a clean energy, the method of large-scale and low-cost production of hydrogen is still being explored. Hydrogen can be produced by using the waste heat of steel slag, but further research is needed to improve the comprehensive utilization rate of steel slag and improve the efficiency of energy gas production. The oxidation of molten slag by injecting H2O-CO2 mixed gas can not only realize the conversion of H2-CO energy gas by the high temperature characteristics of slag, but also convert Fe2+ into Fe3+ to promote the magnetic separation of valuable elements. The competitive reactions between H2O-CO2 with molten slag containing FeO were studied and the effects of gas partial pressure and temperature were investigated. The results showed that in H2O-CO2-Ar mixed injection system, increasing the CO2 partial pressure, the production rates of H2 were dropped significantly, but as for CO production rates, the trend was increased first and then reduced. The reaction rate of mixed gas was better than that of singe gas. CO2 conversion ratio was almost twice that of H2O in mixed gas atmosphere, and when pCO2/pH2O was 0.6, the overall oxidation rate reached the peak value. With raising the temperature, CO generated rates were steady increasing, on the contrary, H2 generated rates were decreased. The mixed gas oxidizing FeO kinetic model of interfacial reaction limiting was showed as following equation: v = 2Akc,CO2p1/2 CO2 + 2Akc,H2Op1/2 H2O(mol/s)