Performance Evaluation of Ni–Al ₂ O ₃ Adsorbents in Diesel Desulfurization and Study on the Structure–Performance Relationship

Fuel oil has the highest output among petroleum products. The incomplete combustion of sulfides in gasoline and diesel pollutes the environment. Focusing on the refractory thiophenic sulfides in diesel, xNi–Al2O3 adsorbents were prepared by the coprecipitation method. A micro fixed-bed reaction device was used to systematically study their desulfurization performance in industrial diesel and simulated diesel, and the adsorbents were characterized by BET, XRD, H2-TPR, H2-HOT, XPS, and so on. The results show that after H2 reduction treatment, under the conditions of normal temperature and pressure and an oil flow rate of 4 mL/h, the adsorption capacity of 40Ni–Al2O3 reaches 0.67 mg/g, showing the best performance and cycle stability. Adsorption experiments on different sulfides indicate that the specific surface area and pore size affect their physical adsorption performance; under the same conditions, the removal effect gradually deteriorates with the increase of molecular weight. Among them, the adsorption capacity of 40Ni–Al2O3 for methyl mercaptan reaches the highest of 3.38 mg/L. The characterization results show that 40Ni–Al2O3 has the largest active specific surface area of Ni, which affects its chemical adsorption, thus exhibiting the best adsorption performance and regeneration performance. At the same time, it exhibits relatively small steric hindrance to methyl mercaptan.