Vapor—solid equilibrium for the CHONi system

The equilibrium states of the CHONi system are defined in relation to H₂CO compositions for temperatures ranging from 300 to 700 K and at atmospheric pressure.The gaseous species, H₂, H₂O, CO, CH₄…C₈H₁₈, C₂H₄… C₄H₈ are taken into account to determine the gas phase compositions imposed by the different equilibria between condensed phases (〈C〉, 〈Ni〉, 〈NiO〉, 〈Ni₃C〉, 〈Ni,C〉 solution).We have particularly investigated the values of chemical potential of carbon in the gas phases, fixed by equilibria between solid phases involving carbon, at which hydrocarbons higher than CH₄ appear. The method for determining the standard free enthalpy of formation of Ni₃C is discussed.