Preparation Of Modified Zeolite And Its Performance Of Adsorptive Desulfurization

Since the vast demand of the diesel recently, the environmental pollution of sulfide compound during the using diesels containing sulfide have been paid more attention, and more stringent regulations have been mandated around the world to further reduce the sulfur level in fuels. The traditional Hydrodesulfurization (HDS) technique can not meet the requirement of deep desulfurization because it’s difficult to remove the fused ring thiophene sulfides, including benzothiophene(BT) and dibenzothiophene(DBT). Adsorption desulfurization technique has the advantages like simple operation, relatively low investment, which attracts much interest in oil refining industry. Herein, this research is to investigate the adsorptive desulfurization over cation-exchanged13X zeolotes, and optimize the preparation conditions and the adsorption conditions of zeolotes to improve the desulfurization rate and adosorption capacity for removing the DBT.Co13X zeolite was prepared via liquid-phase ion-exchange method by dipping13X zeolite with Co2+. The effects of preparation methods and qualification of Co serial sorbents on the removal ability of sulfur were studied by X-Ray diffraction (XRD), NH3temperature-programmed desorption (NH3-TPD), BET surface area measurement, thermo gravimetric analysis (TGA) techniques, and the technique of the static sorption. The experiment results show that when13X zeolite is modified by0.1mol·L-1Co(NO3)2at90℃, the DBT removal ability of Co13X activated at500℃is the highest.Modified zeolite was also prepared via liquid-phase ion-exchange method by dipping13X zeolite with Co2+and Ag+cations respectively, and characterized by Element analysis, XRD, NH3-TPD, BET and TGA techniques. The effects of the concentration of metal cations, adsorptive time and the ratio of fuel and solid on the adsorptive desulfurization of adsorbents in model diesel were investigated by static method and fix-bed balance dynamic sorption tecniques. The results showed that zeolite modified by dual metal ions has better desulfurization performance than that of Co13X and Agl3X zeolites, while the latter have better performance than that of13X zeolite. The absorbents have good adsorption reproducibility and stability.