Effects of temperature, oxygen-to-methane molar ratio and superficial gas velocity on partial oxidation of methane for hydrogen production

摘要

Effects of temperature, inlet oxygen and methane concentrations and superficial gas velocity on the partial oxidation of methane using a Ni/SiO_2 composite catalyst for hydrogen production were investigated experimentally and analytically from an engineering viewpoint. With supply of a gas mixture of x_(O_2)~(in)/x_(CH_4)~(in)= 0.5 at 1 atm pressure, hydrogen was produced most efficiently. The conversion ratio from methane to hydrogen increased with temperature and was 0.92 at 1073 K. With supply of a less methane mixture, the conversion ratio decreased because of water formation. The conversion performance could be well understood by solving the mass-action-law equations and the material-balance equations of hydrogen, oxygen and carbon atoms in the catalyst bed simultaneously. The conversion rate was very fast, and so the conversion ratio was independent of the superficial gas velocity which was slower than 10 s~(-1).