Reactive Adsorption of Sulfur Compounds on Transition Metal Polycation‐Exchanged Zeolites for Desulfurization of Hydrocarbon Streams

Abstract

The reactive adsorption of sulfur‐contaminated compounds over transition metal (TrM) polycation‐exchanged zeolites is a very efficient method for the desulfurization of hydrocarbon processing streams. The process consists of the physical adsorption of thiols, sulfides, and disulfides and the catalytic oxidation of the adsorbed substances. The reaction does not require the participation of free oxygen; diffuse‐reflectance infrared Fourier transform spectroscopy (DRIFTS) and X‐ray absorption spectroscopy (XAS) studies confirmed that the thiol oxidation proceeds through the direct involvement of TrM polycation superoxides. All of the studied zeolite X, zeolite Y, and mordenite materials containing Zn, Mn, Cu, and Cd polycations show remarkable activity for the oxidation of sulfur compounds; this results in a significant increase of the total pick‐up from gas and liquid hydrocarbons. The thermal regeneration of the adsorbent–catalysts under oxidizing conditions leads to the complete restoration of their original activities and capacities for the removal of sulfur compounds. Suitable operating conditions for the regeneration process are disclosed. The study also demonstrates favorable properties of the suggested adsorbent–catalysts for use in commercially important applications such as the desulfurization of natural gas and liquid hydrocarbons.

Difunctional Adsorbents Ni/ZnO–HZSM-5 on Adsorption Desulfurization and Aromatization of Olefin Reaction

“…Therefore, novel adsorbents must be developed for desulfurization and maintaining octane number. Porous materials, such as Al 2 O 3 or SiO 2 and HZSM-5, could be used as matrix owing to their large specific surface area [19]. HZSM-5 possesses large specific surface area, unique micropore channels, and stable structural characteristics.…”