Aluminum is an attractive alternative fuel,but it burns very inefficiently due to the formation of a dense Al_(2)O_(3)layer which prevents O_(2)from diffusion to the surface of Al particles.In previous experiments,the...Aluminum is an attractive alternative fuel,but it burns very inefficiently due to the formation of a dense Al_(2)O_(3)layer which prevents O_(2)from diffusion to the surface of Al particles.In previous experiments,the combustion of millimeter-sized Al(mAl)particles in the fluidized bed has achieved a substantial increase in the combustion efficiency,but further improvements are still needed.In this study,the effects of reaction atmosphere on the fluidized combustion of mAl particles were investigated.The experiments with different O_(2)/H_(2)O/CO_(2)concentrations were conducted.The experimental results indicate that the combustion efficiency of mAl particles in fluidized bed increases as the mole fraction of O_(2),H_(2)O or CO_(2)increases,and the highest combustion efficiency can reach 38.7%.After the analysis of the oxide film on the surface of aluminum particles,it was found that it is easier to generate the unstableθ-Al_(2)O_(3)under CO_(2)atmosphere,and it is easier to generate the unstableγ-Al_(2)O_(3)andθ-Al_(2)O_(3)under H_(2)O atmosphere.The unstable Al_(2)O_(3)film is more likely to be abraded in the fluidized bed,which leads to the effective improvement of the combustion efficiency.展开更多
基金supported by the National Key R&D Program of China(grant No.2020YFC1910000).
文摘Aluminum is an attractive alternative fuel,but it burns very inefficiently due to the formation of a dense Al_(2)O_(3)layer which prevents O_(2)from diffusion to the surface of Al particles.In previous experiments,the combustion of millimeter-sized Al(mAl)particles in the fluidized bed has achieved a substantial increase in the combustion efficiency,but further improvements are still needed.In this study,the effects of reaction atmosphere on the fluidized combustion of mAl particles were investigated.The experiments with different O_(2)/H_(2)O/CO_(2)concentrations were conducted.The experimental results indicate that the combustion efficiency of mAl particles in fluidized bed increases as the mole fraction of O_(2),H_(2)O or CO_(2)increases,and the highest combustion efficiency can reach 38.7%.After the analysis of the oxide film on the surface of aluminum particles,it was found that it is easier to generate the unstableθ-Al_(2)O_(3)under CO_(2)atmosphere,and it is easier to generate the unstableγ-Al_(2)O_(3)andθ-Al_(2)O_(3)under H_(2)O atmosphere.The unstable Al_(2)O_(3)film is more likely to be abraded in the fluidized bed,which leads to the effective improvement of the combustion efficiency.
