Abstract:
Chemical looping combustion technology is one of the most promising CO2 capture technologies at present, and oxygen carrier is a key component of this technology. Iron-based oxygen carriers are considered to have the most potential for industrial application due to their wide source, low price and environmental friendliness. The short lifetime and the weak oxygen transport capacity of oxygen carriers hinder the commercial operation of chemical looping combustion technology. In this paper, Fe-Al composite oxygen carriers with calcination temperature of 1 300 ℃, 1 400 ℃ and 1 500 ℃ were prepared by mechanical mixing method, and several groups of fluidized bed wear tests were carried out in cold, hot and reactive states, respectively, and the calcination temperature was analyzed. The effects of oxidation and reduction reactions on the wear and oxygen release capacity of the oxygen carrier were studied respectively, and the effects of mechanical collision, temperature and chemical reaction on the wear of the oxygen carrier were clarified. The research results show that the oxygen carriers calcined at 1 400 ℃ exhibits the best balance between wear resistance and cycle stability, based on the analysis of element distribution, crystal phase separation and micromorphological evolution on the surface of the oxygen carriers before and after the reactions, and it was found that the increase in the pore volume of oxygen carriers caused by the reduction reaction in the chemical reactions plays an important role in its wear and fragmentation. This work has a certain guiding effect on the development and design of long-life composite oxygen carriers.