Adsorption-desorption behavior and mechanism of dimethyl disulfide in liquid hydrocarbon streams on modified Y zeolites

Removal of organic sulfur compounds from its solution has been investigated by using adsorption on the ion-exchanged Y zeolites. Effects of metal cations, calcination temperature and reaction temperature on the removal efficiency have been accessed by performing the dynamic and static tests. The adsorbents were characterized by X-ray fluorescence analysis (XRF), X-ray diffraction (XRD), thermal analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Pyridine-FTIR spectroscopy showed that Lewis acid is contributed to increase the adsorption capacity, while Bronsted acid has an adverse effect on the desulfurization capability. Spectral shifts of the v(C-S), v(S-S) and v(Cu-S) vibrations of the Cu-Y zeolite after adsorption of DMDS were measured with the Raman spectrum. In situ Fourier transform infrared (FTIR) and temperature-programmed desorption of DMDS (DMDS-TPD) results indicated that the adsorption mechanisms on Cu(I)-Y zeolite was the S-M (sigma) bond which formed to increase adsorption bond energy of DMDS. (C) 2013 Elsevier B.V. All rights reserved.