Study of the System of Two Parallel Reactions—Carburization of Nanocrystalline Iron and Formation of a Carbon Deposit

The reaction system of nanocrystalline iron carburization and carbon deposit formation as an example of a parallel chemical reaction was studied. The main measurement procedure was the Chemical Potential Programmed Reaction method, according to which the course of a chemical reaction in this particular case was controlled by the methane–hydrogen mixtures of precisely selected variable composition. The measurements were performed in a tubular differential flow reactor with thermogravimetric measurement and analysis of the gas phase composition at a temperature of 650 °C under atmospheric pressure. In the current research, by measuring the mass of the solid sample at changing carburizing potential and after balancing the reacting system, the reaction rates of parallel iron carburization and carbon deposit formation were precisely determined using the model of the reaction of a nanocrystalline substance with the gas phase in states close to chemical equilibrium. The reaction rate constants for those reactions were estimated as well based on model equations.