Preparation and dynamics property of perovskite-type oxygenates prepared by methane chemical chain reforming for syngas production

The perovskite type oxide LaFeO3 was prepared as the oxygen carrier by combustion method, microemulsion method, co-precipitation method and sol-gel method for the chemical synthesis of methane by the chemical chain reforming process. The oxygen carrier was characterized by means of X-ray diffraction(XRD), scanning electron microscopy(SEM), hydrogen temperature-programmed reduction(H2-TPR)and Brunauer-Emmett-Teller Specific surface area(BET)and other technology. The reaction performance of LaFeO3 and methane prepared by four methods was investigated on a fixed bed reactor to seek for the best preparation method of oxygen carrier for methane chemical chain reforming process, and then the reduction kinetics of LaFeO3 was explored by H2-TPR multi-rate heating process. The results showed that the oxygen carriers prepared by four methods are all formed perovskite structure, LaFeO3 prepared by sol-gel method and combustion method are better in purity and crystallinity, there is no heterophasic formation. From the viewpoints of CH4 conversion, n(H2)/n(CO), CO and H2 selectivity, the oxygen carrier prepared by combustion method has the best performance, and using for syngas production by the chemical reforming of methane has the best effect. The kinetic calculation of H2-TPR shows that the activation energy of low temperature oxygen adsorption reduction of LaFeO3 oxygen carrier is 97.001 kJ/mol and the activation energy of high temperature lattice oxygen reduction is 30.388 kJ/mol. © 2018, Editorial Board of Acta Energiae Solaris Sinica. All right reserved.