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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. [ABSTRACT FROM AUTHOR]

Flowsheets based on the results of experimental studies and detailed kinetic modeling were suggested for oxidative cracking of oil refinery gas components to obtain ethylene, CO, and hydrogen. The calculations show that oxidative cracking alone does not allow production of ethylene and СО in ratios required for the further catalytic carbonylation and hydroformylation of ethylene. Matrix conversion of a part of oxy-cracking products is suggested as an additional step for producing CO and hydrogen. [ABSTRACT FROM AUTHOR]

Effect of hydrogen addition at [C2H6]/[H2] ratios of 10-0.05 on the oxy-cracking of ethane was experimentally studied. It was shown that small additions of hydrogen have nearly no effect on the process rate. With the concentration of added hydrogen increasing at temperatures of up to ~650°C, the contributions from the reactions of oxidation of both hydrogen itself and starting ethane becomes more pronounced, with water, carbon oxides, methane, and ethylene being the main reaction products. With increasing temperature, the influence exerted by small additions of hydrogen on the conversion of ethane and oxygen decreases. Performing the oxidative cracking in hydrogen at temperatures higher than 650°C demonstrated that hydrogen makes the conversion of ethane smaller and the expenditure of oxygen for oxidation of hydrogen grows. [ABSTRACT FROM AUTHOR]