Abstract: The adsorptive denitrogenation performance of ZSM-5 zeolites with different silica-to-alumina ratios for the removal of pyridine, aniline, and quinoline from simulated fuel was investigated, along with the effects of adsorbent dosage, adsorption temperature, and adsorption time. The results show that ZSM-5 with a silica-to-alumina ratio of 50 (Z-50) exhibited the best denitrogenation performance. Its capacity for removing basic nitrogen compounds follows the order: pyridine > aniline > quinoline. For 15 mL of simulated fuel with a nitrogen content of 1732 μg/g, the optimal conditions were determined as follows: Z-50 dosage of 1.5 g, adsorption temperature of 303 K, and adsorption time of 30 min. Models of Z-50 zeolite and the basic nitrogen compounds were constructed using Materials Studio molecular simulation software, and the adsorption energy, adsorption type, and adsorption behavior were simulated and calculated. The results indicate that the adsorption capacity of Z-50 for the three nitrogen compounds decreased in the order: pyridine > aniline > quinoline. The adsorption of pyridine, aniline, and quinoline on Z-50 follows the Langmuir-Freundlich hybrid model, suggesting that the adsorption involves both monolayer and multilayer mechanisms. The adsorption behavior of pyridine on Z-50 zeolite conforms to the pseudo-first-order kinetics, with diffusion being the key factor affecting the adsorption efficiency. In contrast, the adsorption of aniline and quinoline follows the pseudo-second-order kinetics more closely, indicating that the number of remaining active sites on the adsorbent surface primarily influenced the adsorption process.

Key words: ZSM-5, silica-to-alumina ratio, simulated fuel, adsorption denitrification, simulation calculation