Kinetic Study of Simultaneous Ethanol Decomposition and Reduction of Low-grade Iron ore at Transient Temperature

Abstract

Abstract An ethanol-assisted ironmaking method had previously been proposed, resulting in a significantly lower temperature of iron reduction. However, the kinetic mechanism remains unknown. A kinetic model for transient temperature condition was introduced, then numerically solved and curve-fitted to the experimental data using MATLAB software. There were 8 main reactions involved: (1) decomposition of ethanol, (2) decomposition of methane, (3) steam reforming of methane, (4) water-gas shift, (5) Boudoard reaction, (6) direct reduction by C, (7) indirect reduction of iron oxide by CO, and (8) iron reduction by H2. Curve fitting methods were successfully conducted with satisfying results (R2 > 0.90) calculating three parameters consisting of reaction rate constants, activation energies, and diffusion factors of each reaction. The interpretation of the calculated diffusion factors reveals that the reaction of gases inside pore might be inhibited by carbon deposition on the pore surface of iron ore. It revealed that the direct reduction by C predominates the overall reduction process.