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چکیده
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Abstract In this work, new nanocomposite adsorption catalysts composed of Zn-zeolitic imidazole framework (ZIF-8) doped with Fe and Cu, Eight adsorber samples with different molar ratios [ Zn-ZIF-8, Zn/Cu-ZIF-8 (25:75,50:50,75:25), Zn/Fe-ZIF-8(25:75,50:50,75:25) and Zn/Cu/Fe-ZIF-8(50:50:50)] were synthesized and characterized by different techniques including powder XRD, FESEM, BET and FTIR. The best catalysts were selected based on the efficiency of removing sulfur from model fuels (dibenzothiophene, DBT in n-hexane) under specific parameters (model fuel volume = 100 ml, DBT concentration = 50 mg/L, and adsorbent dose = 1 g/L). The Zn/Cu-ZIF8 (75:25), Zn/Fe-ZIF8 (75:25) and Zn/Cu/FeZIF8(50:50:50) hybrid adsorbers have showed higher efficiency in removing sulfur, compared with undoped ZIF-8 due to the highly efficient π-complications between Cu and Fe nods and the DBT molecules. Furthermore, the effect of DBT concentration (21 ppm, 44 ppm, and 89 ppm), dosing of catalyst (1g/L, 2g/L, and 3g/L) and contact time were studied using the best catalyst samples [Zn/Cu-ZIF8 (75:25), Zn/Fe-ZIF8 (75:25) and Zn/Cu/FeZIF8(50:50:50)]. The Zn/Cu-ZIF8 (75:25), Zn/Fe-ZIF8 (75:25) and Zn/Cu/FeZIF8(50:50:50) samples were exhibited DBT adsorption rate of 93.8% 94.7% ,97.6% respectively, at a concentration (DBT) of 21 ppm. The Kinetic and isotherm studies were prformed. Pseudo-first-order model, and Freundlich isotherm model were identical with the expermental data. Moreover, the performance of the best catalysts [Zn/Cu/FeZIF8(50:50:50)] was evaluated through deep desulfurization of real fuel (light naphtha), and the sulfur removal succeeded from 23 ppm to 0.7 ppm.
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