Reactive Adsorption Desulfurization of FCC Gasoline over Ca-Doped NiO/ZnO-Al₂O₃-SiO₂ Adsorbents

A Ca-doped NiO/ZnO-Al₂O₃-SiO₂ adsorbent was prepared by impregnation method and compared with S-Zorb adsorbent. BET, XRD and in situ pyridine adsorption infrared spectroscopy were adopted to characterize the structure of the adsorbent. Results show that the adsorbent has a special surface area of 137.7 m²/g and pore volume of 0.31 cm³/g, more uniform distribution of NiO and ZnO, and larger amount of L acid. The desulfurization experiment indicates that the content of sulfur decreases from 243.38 μg/g to less than 10 μg/g, with a reduction of octane number by only 0.3 at the temperature of 420℃, pressure of 2.9 MPa, WHSV of 10.98 h^-1, and volume ratio of hydrogen to gasoline 48:1. The sulfur capacity of the fresh adsorbent and regenerated adsorbent are 57.12 mg/g and 47.33 mg/g, respectively. The performance of the adsorbent maintains excellent after being regenerated for dozens of times. Adsorbents characterization data of physical property analysis and photoelectron spectroscopy reveal that the performance of regenerated adsorbents is improved significantly and ZnO acts as sulfur-accepter to convert sulfur to ZnS eventually.