Study of hydrogen production kinetics using isotope exchange method

Abstract

A novel isotope exchange method is developed for measuring the rate constant of hydrogen production from water and steelmaking slag. In the reaction equilibrium state, the D2-H2O gas mixture of suitable composition was introduced into the steelmaking slag for isotope exchange reaction while the composition of the reacted gas was monitored online by a mass spectrometer. Based on the change of isotopic gas composition, the apparent reaction rate constant can be obtained by equations. The results show that the apparent rate constant of the reaction increases with the increase of temperature, whereby the apparent rate constant at 1873K was approximately 21.6% higher than that at 1723 K. The apparent activation energy of the reaction was 35.51 ± 1.17 kJ/mol, which the probable rate controlling steps of reaction was biased towards interfacial chemical reaction.