The Study Of CO Combustion Over CuMnCe-O/γ-Al₂O₃ Catalyst In The Catalytic Cracking Regenerator

Nitrogen oxides（NO,NO₂ and N₂O）are notorious air pollutants that cause acid rain,photochemical smog,ozone destruction and greenhouse effects.NO_x emitted into the air from fluidized catalytic cracking（FCC）regenerators（NO 90%,N₂O 10%）accounted for about 10%of the total NO_x emissions in the air.How to effectively realize the complete conversion of CO in the flue gas of FCC and reduce the emission of NO_x has become an important subject of common concern and urgent problems in the oil refining domestic and foreign scholars.In this paper,a series of CuCe-O/γ-Al₂O₃,CuCeLa-O/γ-Al₂O₃,CuMnCe-O/γ-Al₂O₃ and CuMnCeLa-O/γ-Al₂O₃ catalysts were prepared by an improved amorphous citric precursor method.And the phase structure and surface properties of these catalysts were characterized by XRD and H₂-TPR.The catalytic performance of these catalysts was investigated by CO+O₂ and CO+NO gas.The effects of different additives on the catalytic cracking reaction-regeneration performance of SY-100 catalysts were studied by using RU-Ⅱmultifunctional riser reactor.The following conclusions were obtained:The XRD results showed that CuO,MnO_x,CeO₂ and La₂O₃ active components of the CuMnCeLa-O/γ-Al₂O₃ catalysts in the carrierγ-Al₂O₃surface were highly dispersed.H₂-TPR results illustrated that the addition of Mn and La changes the H₂-TPR temperature of CuMnCeLa-O/γ-Al₂O₃catalyst.And the H₂-TPR temperature of CuMnCeLa-O/γ-Al₂O₃ catalyst gradually shifts to the lower temperature region with the Cu:Mn molar ratio gradually increasing.The results of CO oxidation and NO reduction showed that CuMnCeLa-O/γ-Al₂O₃ catalyst exhibits better CO oxidation activity and NO reduction performance.The conversion of CO oxidation and NO reduction of CuMnCeLa-O/γ-Al₂O₃ catalyst reaches 86.0%and 75.6%at300℃,respectively.The results of the CO combustion and NO denitration demonstrated that,compared with the Changling Pt promoter,the concentration of CO emitted from regenerator flue gases over CDNP-27 promoter was 0.08%higher,while the concentration of NO was decreased from 136 ppm to 45 ppm.It is indicated that the NO denitration effect was significantly improved than that of the Changling Pt promoter.Adding CDNP-27 additive has little effect on the distribution of catalytic cracking products of SY-100 catalyst.