Study on reduction performance and kinetics of Sr-modified LaFeO3 for methane chemical looping reforming
Chemical looping reforming of methane is a novel low-carbon hydrogen production technology.The reduction characteristics of the oxygen carrier are key factors determining the hydrogen production rate of chemical looping reforming.The effect of different proportions of Sr doping on the reduction characteristics of LaFeO3 was discussed in detail.By characterizing the octahedral distortion and surface oxygen morphology of FeO6,the effect of Sr doping on oxygen vacancy concentration and lattice oxygen transfer was analyzed.La08Sr02FeO3 exhibits significant FeO6 octahedral distortion,showing the lowest lattice oxygen reduction temperature at 750℃.In isothermal reduction,the maximum mass loss of La0.8Sr0.2FeO3 is 2-3 times that of LaFeO3.Kinetic fitting calculations revealed that the reduction process of La1-xSrxFeO3 is controlled by the nucleation and growth model,while also being influenced by the autocatalytic model.Among the four oxygen carriers,La0.8Sr0.2FeO3 exhibits the lowest apparent activation energy.The mass gain rate of La08Sr02FeO3 in steam oxidation experiments is about 4 times that of LaFeO3,and it maintains its original phase after 20 cycles.The study of La1-xSrxFeO3 in chemical looping reforming and multi-cycle stability provides technical and data support for the selection of materials and process optimization in methane chemical looping reforming for hydrogen production.
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