Ethane formation via catalytic low-temperature steam reforming of C₃₊-alkanes

The present work aims at studying low-temperature steam reforming (LTSR) of model mixtures of flare gases containing C₂H₆-C₄H₁₀ in methane excess over a highly dispersed Rh-based catalyst. 1 wt% Rh/Ce_0.75Zr_0.25O₂ catalyst was prepared by sorption-hydrolytic deposition. Catalytic properties were studied in the LTSR of model fuel gas mixtures at 200–350 °C. The catalysts provided complete conversion of C₂₊-hydrocarbons into CH₄, CO₂ and H₂ at 320–350 °C. The conversion of propane and heavier alkanes over Rh at low temperature (200–300 °C) allows obtaining high ethane concentrations in the products, which is not observed in the case of nickel catalysts. The influence of hydrogenolysis reaction to ethane formation is discussed. Ethane has a higher calorific value than methane and can compensate the negative effect of the product gas dilution by carbon dioxide and hydrogen that are formed in the reaction. This can be useful for adjusting the fuel properties (calorific value, Wobbe index, methane number) of the resulting gas mixtures.