The present work aims at studying low-temperature steam conversion of model flare gas mixtures containing C 2 H 6 -C 5 H 12 in methane excess over industrial Ni-based catalyst. It is shown that at 250–350 °C and H 2 O/C C2+ molar ratio of 0.7–1.0, steam conversion can be applied to convert C 2+ -hydrocarbons into CH 4 , CO 2 and H 2 , which results in the lowering net calorific value, the Wobbe index and dew point temperature of the gas obtained. However, complete conversion is not necessary for certain applications. In these cases, kinetically controlled partial conversion of ethane and propane enables one to obtain methane-rich mixtures with desired calorific properties for various applications. This idea has been experimentally verified. Kinetic study of C 2 H 6 -C 5 H 12 low-temperature steam conversion has been performed. A simple macrokinetic model, which included irreversible first-order kinetics for C 2 H 6 -C 5 H 12 steam conversion and quasi-equilibrium mode for CO 2 methanation, has been suggested. The model adequately describes the experimental data on the conversion of model flare gas mixtures at various temperatures and flow rates and has been applied to predict the reaction conditions which would allow one to obtain methane-rich mixtures with the desired properties for various applications.