Study On Oxygen Carriers For Chemical Looping Combustion Of Coal

The world becomes warm, which causes a series of negative influence to warning the behavior of people. As the majority of glasshouse air, how to separate and recover CO₂ for recycling use will become one of the most important energy and environmental problems in 21 century. According to the principle of zero emission, chemical looping combustion could not only availably enrich CO₂, but also could lift high-efficiency of energy use and carry out control of various pollutants. The thesis bases research on oxygen carriers for realization chemical looping combustion of solid fuel coal.After analysis the research has been done about oxygen carriers in chemical looping combustion. And consider the request of oxygen carriers for coal on chemical reaction and so on. Al(OC₃H₇)₃ and Ni(NO₃)₂ have been selected as main raw materials to prepare sol-gel-derived NiO/NiAl₂O₄ oxygen carriers. XRD, FSEM and BET have been used to analyze its physical and chemical property. The results are described as follows: The components of fresh oxygen carriers are NiO and NiAl₂O₄, which attain the purpose of experiments completely. At the same time, it has good physical property, such as rather high surface area, large pore volume and big pore size.NiO/NiAl₂O₄ oxygen carriers have been used for circular reaction with char/air and hydrogen/air in pressed tagged graphics. And oxygen carriers after circular reaction have been analyzed with XRD, FSEM and BET. The results are described as follows: When the temperature higher than 850℃, NiO/NiAl₂O₄ reacted with char rapidly, which means that the oxygen carrier has good reaction activity. The experiment testifies the feasibility of chemical looping combustion of coal also. In the process of NiO/NiAl₂O₄ circular reacted with hydrogen/air. The chemical reaction of the oxygen carrier presents slow-moving increment. After circular reaction for many times, the surface area and pore volume of the oxygen carrier decreased in a small range. But its'pore size increased a bit. There isn't exists any sintering between different grains. The oxygen carrier remains its beehive form.