Non-Catalytic Partial Oxidation of C2+ Hydrocarbon/H2 Mixtures

The paper reports the results of a kinetic and thermodynamic analysis of non-catalytic partial oxidation of methane and C₂–C₄ hydrocarbon/hydrogen mixtures (C/H = 1 : 4) at 1400–1700 K. The hydrocarbon conversion sequence and the time periods of the major process stages were identified for isothermal conditions. The initial stage of the oxidative conversion of C₂₊ hydrocarbons consists of their pyrolysis, primarily into ethylene and propylene, followed by oxidation of the pyrolysis products. In this respect, the kinetics of C₂₊ hydrocarbon oxidative conversion are different from those of methane conversion, marked by the almost simultaneous and significantly slower occurrence of pyrolysis and oxidation. The subsequent stages involve steam and dry reforming of the oxidation products, namely acetylene and methane; these stages continue until the main products (H₂, CO, CO₂, and H₂O) reach an equilibrium distribution for the given temperature. The study findings are important for the optimization of various techniques for high-temperature syngas production via partial oxidation of C₂₊ hydrocarbons, as well as Moderate or Intense Low-Oxygen Dilution (MILD) combustion processes.