Study On Catalysts Used For Simultaneous Removal Of SO₂and NO From Fuel Gas With Co As Reducing Agent

Nitric oxide(NO) and sulfur dioxide(SO2), which are the two major pollutants causing photochemical smog and acid rain, are from refining of oil and combustion of coal. The Fluid Catalytic Cracking (FCC) is one of the most important gasoline-producing process in refinery. Amounts of (SOx, NOx, CO), which are harmful for human being, are generated with the FCC operations. For a long while, much attention has been paid on the removal of SO2and NO simultaneously because of environmental protection requirement. One of the important method to remove SO2and NO is Selective Catalytic Reduction(SCR). The catalytic reduction of SO2and NO is desirable for its great value in theory and practicality by CO, because it can reduce SO2to sulfur and NO to nitrogen simultaneously.In this paper, a series of hexaaluminate and TiO2catalysts were prepared by co-precipitation and impregnation method. The structure and physic-chemical properties of the prepared samples were characterized by means of X-ray diffraction (XRD), H2-TPR, BET and Scanning Electron Microscope (SEM) techniques. The activities of the catalysts for DeSOx and DeNOx were investigated in a miniature fixed bed reactor. The results showed that:1.The catalysts prepared under1200℃calcination for4h possessed complete crystal structure of hexaaluminate.2.Research was operated on hexaaluminate catalysts doped with single ions Mn, Fe, Cu, Ni and Cr. Results showed that Cu and Fe contributed to form the hexaaluminate lattice due to their good synergistic reaction, the hightest DeSOx conversion ratio reached82.1%,85.0%and DeNOx91.7%,96.2%respectively. Double ions doping catalysts had higher activity than single one both in DeSOx and DeNOx process. SrCu0.4Fe0.6Al11O19-δ catalyst exhibited the highest catalytic activity for DeSOx&DeNOx with SO2conversion ratio more than91%and NO more than99%.3.The catalysts prepared under550℃calcination for4h possessed complete crystal structure of TiO2.4. Research was operated on TiO2catalysts doped with single ions Ni, La, Fe, Cu and Cr. Results showed that Cu and Ni doped catalysts exhibited higher activities. DeSOx conversion ratio reached81.2%,88.0%and DeNOx76.8%,88.5%respectively. Double ions doping catalysts had higher activity than single one both in DeSOx and DeNOx process.5%CuO-5%NiO/TiO2catalyst exhibited the highest catalytic activity for DeSOx&DeNOx with SO2conversion ratio more than95%and NO more than96%.