Study On Chemical Looping Combustion Characteristics Of Fe₂O₃?104?and CO Under Synergistic Action Of ZrO₂/TiO₂ Carrier And Carbon Deposition Analysis

While coal-based fossil fuels meet the needs of electricity generation and energy,the emission of CO2 during the combustion process also causes the concentration of carbon dioxide in the atmosphere to increase.The emission of greenhouse gases such as carbon dioxide is an important cause of global warming.Therefore,it is imperative to reduce the emission of CO2 during coal utilization.Chemical looping combustion(CLC)is a new type of high efficiency combustion technology.CLC avoids the direct reaction of fuel with air and the resulting CO2 and H2O are not mixed with air so that efficient capture of CO2 can be achieved without consuming additional energy.At the same time,it inhibits the formation of NOx and therefore attracts much attention.The oxygen carrier is one of the key constraints of chemical chain combustion technology.The performance of oxygen carrier plays an important role in the chemical chain combustion performance.On the basis of the previous studies on the enhancement of chemical reaction of iron-based oxygen carrier Fe2O3(1014)by the control of the surface morphology,this paper further studies the effect of high-Maire index iron-based carrier Fe2O3(104)Reaction characteristics of chemical looping combustion.First,we prepared two different inert carrier composite iron-based oxygen carrier:Fe2O3(104)/TiO2 and Fe2O3(104)/ZrO2,the prepared oxygenates Fe2O3(104)/TiO2 and Fe2O3(104)/ZrO2were characterized by XRD,SEM and BET.Then,the combustion characteristics of oxygen carrier and CO chemical chain at 700?,800? and 900? were studied.The results showed that the effect of different carriers on the reactivity of Fe2O3(104)and CO in chemical chain combustion was different ZrO2 as a carrier obviously promoted the reaction rate of iron-based oxygen carrier Fe2O3(104)with CO.Furthermore,the kinetic analysis shows that the reaction model of Fe2O3(104)/TiO2 with CO belongs to the first-order reaction model and the activation energy is 153.6 kJ-mol-1.The reaction model of Fe2O3(104)/ZrO2 with CO belongs to the shrinking sphere Model,the activation energy is 118.9 kJ-mol-1.The results can provide guidance for the optimization application of high-Maitrel iron-based oxygen carrier and provide a more reasonable kinetic model for the design of chemical-reaction-coil reactor.Finally,the effect of the inert oxide support on the surface area carbon of the supported iron-based oxygen carrier was investigated by elemental analysis.The results show that the reaction of Fe2O3(104)/TiO2 with CO shows better performance,so TiO2 can inhibit the carbon deposition.