Denitrogenation and desulfurization of model oil through adsorption process using one-pot-synthesized reusable CYCU-3@Al2O3 composites

Abstract

Adsorptive denitrogenation and desulfurization are of great importance owing to their mild operating conditions, no requirement of hydrogen, and high quality of the gasoline distillate. Herein, we report the facile one-pot synthesis of CYCU-3@Al₂O₃ composites via the reaction of 4,4′-stilbenedicarboxylic acid as a ligand and γ-Al₂O₃ beads as a support. The synthesized composites were fully characterized using various analytical instruments and applied as an adsorbent for the removal of sulfur- and nitrogen-containing compounds (SCCs and NCCs) from a model oil. The CYCU-3@Al₂O₃ composite with 12.7% loading of CYCU-3 was observed to be very efficient adsorbent not only for SCCs with the adsorption capacity being 360.2 mg (1.95 mmol) dibenzothiophene per gram of MOF, 163.2 mg (1.22 mmol) benzothiophene per gram of MOF, 134 mg (1.59 mmol) thiophene per gram of MOF, but also for NCCs with the adsorption capacity being 288 mg (3.64 mmol) pyridine per gram of MOF, 315 mg (2.44 mmol) quinoline per gram of MOF, 340 mg (1.89 mmol) acridine per gram of MOF, 175 mg (1.49 mmol) indole per gram of MOF. Furthermore, about 98–99% of the desulfurization and denitrogenation capacities were recovered after the regeneration of the composites. The main factors responsible for the excellent adsorption performance of the adsorbent include its high surface area and porosity, specific pore size and presence of bridged hydroxide groups and aromatic rings in the organic ligand.