Removal of sulfur compounds from LPG by heteropoly acid-modified spent FCC catalyst

Modified spent FCC catalysts were prepared and the desulfurization properties of these adsorbents were examined in this paper. The experiment data indicated that the spent FCC catalyst performed well in desulfurization after modification; the sulfur content in the liquified petroleum gas (LPG) dropped down to 5 similar to 10 mg.m(-3). X-Ray Fluorescence, X-ray diffraction, Nitrorms and Fourier transform infrared were applied to characterize these adsorbents. Results showed that the content of various metals in spent FCC catalyst was significantly higher than fresh catalyst; and the metals which deactivated the FCC catalysts became the active sites for desulfurization. In addition, a moderate amount of Lewis acid sites is advantageous to desulfurization while too many Lewis acid sites played a negative role.