Impact of Ni content on the structure and adsorption desulfurization performance of Ni/ZnO-TiO₂ adsorbent

Using ZnO-TiO₂ as a carrier support, Ni/ZnO-TiO₂ gasoline desulfurization adsorbents with different Ni contents were prepared by equal volume impregnation method and characterized by X-ray diffraction (XRD), Mercury intrusion porosimetry, H₂-temperature-programmed desorption(H₂-TPD) and H₂-temperature-programmed reduction (H₂-TPR). Meanwhile, the desulfurization performance of the Ni/ZnO-TiO₂ adsorbents were evaluated using FCC light gasoline in a fixed bed reactor. The results show that proper increase of Ni content has little effect on the specific surface area, internal pore distribution and particle strength of the adsorbent, and can increase the Ni⁰ species with desulfurization activity and promote the desulfurization activity of the adsorbent. When the content of Ni in the adsorbent is too much, the internal pore distribution of the adsorbent changes, and the specific surface area and particle strength of the adsorbent are greatly reduced, which is extremely detrimental to the desulfurization activity of the adsorbent. When the Ni content is 4.45%, having the best desulfurization performance, can reduce the total sulfur content of 3×10^-4 in FCC light gasoline to below 5×10^-6, and maintain the desulfurization time up to 152 h, and the breakthrough sulfur capacity is 11.24% (112.4 mg S/g adsorbent). And the olefin content of FCC light gasoline after desulfurization changes little.