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An investigation on a direct partial oxidation of methane to synthesize gas on AFeO3 (A= La, Nd, Eu) oxides by a novel sequential redox cyclic reaction in the absence of gaseous oxygen is conducted over a fixed-bed reactor. The pulse experiments at different temperatures reveal that the rate of oxygen migration during the CH4 reaction with LaFeO3 is strongly affected by the reaction temperature, and increases with rising temperature, which is favorable to much more CH4 selective oxidation at high temperature.

A new process is described for hydrogen production, which combines the water-gas shift (WGS) with a redox mode by using lattice oxygen as the sole oxidant instead of gaseous oxygen in a fixed-bed reactor. The results have shown that the new route is superior to general partial oxidation of methane (POM) in stability, safety, ease of operation and optimization and low cost.

Direct partial oxidation of methane to synthesis gas on AFeO3(A La, Nd, Eu) oxides by a novel sequential redox cyclic reaction in the absence of gaseous oxygen was investigated over a fixed-bed reactor. These oxides were prepared by the sol-gel method and characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques. XRD analysis showed that all AFeO3(A La, Nd, Eu) oxides, calcined at 1173 K, are single-phase perovskites. The CH4-TPSR/MS and continuous reaction experiments indicated that the AFeO3(A La, Nd, Eu) oxides provide mostly oxygen species, as the sole oxidant originated from lattice oxygen instead of gaseous oxygen, which can oxidize CH4to synthesis gas with high selectivity in the absence of gaseous oxygen. In terms of material economics and the amount of oxygen species for synthesis gas formation, the LaFeO3sample exhibits the best performance among these tested AFeO3oxides for synthesis gas production. The pulse experiments at different temperatures showed that the rate of oxygen migration during the CH4reaction with LaFeO3is strongly affected by the reaction temperature, and increases with rising temperature, which is favorable to much more CH4selective oxidation at high temperature. The two types of oxygen species are identified by experiments of continuous reactions and pulses, and confirmed by XPS. Methane can be converted selectively to synthesis gas by consumption of lattice oxygen, and general carbonaceous deposits on the catalyst surface do not occur under the appropriate reaction conditions by sequential redox cycles. The performance of selective oxidation of CH4to synthesis gas can be recovered by reoxidation using gaseous molecular oxygen; the LaFeO3oxide maintains relatively high catalytic activity and structural stability in redox atmospheres. [ABSTRACT FROM AUTHOR]