CaSO 4Study On CO Chemical Chain Combustion Reaction Of /CaO Oxygen Carrier

Chemical looping combustion?CLC?is a novel combustion technology.It is different from the traditional combustion.In the chemical looping combustion system,the fuel does not react with the air directly instead of useing oxygen carrier.It could not only avoid NOX emission,obtained and captured high pure CO₂,but also can achieve a very high efficient use of energy.In short,chemical looping combustion in the field of CO₂ reduction has a high research value and a good application prospects.Oxygen carrier is crucial to the CLC process,CaSO₄ is considered a popential substitute for fautre industrial applications,because of rich reserverse,low prices,high oxygen capacity.In the chemical looping combustion process CaSO₄ oxygen carrier suffers the problems of sulfur release in the form of gas sulfide and affect its life,so control of the release of gaseous sulfides is the key to the study of CaSO₄ oxygen carriers.Calculate the migration of sulfur elements and the migration route in the chemical looping combustion process of CaSO₄/CaO composite oxygen carrier by thermodynamics.In this paper,oxygen carriers CaSO₄/CaO are prepared by mechanical mixing method.Some CaO/CaSO₄ composite oxygen carriers were prepared by chemical modification.The reduction reaction and cycling performance of CaSO₄/CaO composite oxygen carriers with different reaction temperature,different CaO/CaSO₄ molar ratio and different CO concentration were studied.The effects of reaction conditions on CO₂ formation and sulfide release were discussed.The flue gas analyzer and gas chromatograph were used to analyze the composition and concentration of the reaction tail gas.The combustion cycle performance of the composite oxygen carrier in CO atmosphere was studied.The solid content and solid morphology of the solid residue were characterized by XRD,XPS and SEM-EDS.The results show that the addition of CaO not only plays the role of sulfur fixation in the constant temperature test,but also accelerates the reaction rate and increases the CO conversion rate.In the redox cycle,the release of SO₂ in the initial stage of the reduction stage is more significant,and the SO₂ release peak decreases with the increase of the number of cycles.CaCO3 calcined CaO as the source and the HNO3 acidified CaSO₄ compound prepared by the composite oxygen carrier has a good reactivity,and in the 900 ? constant temperature reaction can inhibit the production of SO₂ and COS.