Synthesis and application of magnetic NaY zeolite composite immobilized with ionic liquid for adsorption desulfurization of fuel using response surface methodology

Magnetic NaY zeolite immobilized with 1-butyl-3-methylimidazolium tetrachloroferrate ([bmim]Cl/FeCl3) ionic liquid as a reusable, efficient, and easily separable adsorbent was synthesized to remove dibenzothiophene from n-hexane. SEM–EDX, FT-IR were used for characterization of the synthesized magnetic sorbent. The prepared ionic liquid was characterized by with NMR, and mass spectrometry. The magnetic property of the sorbent was considered by VSM method. The obtained saturation magnetization of 19.5 emu g−1 confirmed the facile separation of magnetic zeolite immobilized with [bmim]Cl/FeCl3 after adsorption process. Central composite design was applied to predict the proposed process and to achieve the optimum conditions for three influential parameters of temperature, time, and sorbent mass. At the predicted conditions, temperature of 23.2 °C, time of 24.7 min, and sorbent mass of 0.836 g, the sulfur removal of 97.9 ± 0.5 % was experimentally obtained which was close to the model sulfur removal prediction of 98.4 %. This noticeable agreement proved the proper and acceptable estimation of the central composite design model for the proposed process. The experimental data were reasonably fitted to the Langmuir and Freundlich model which shows that the sorption takes place on a heterogeneous material. The sorption capacities of 2.957 (mg g−1) were achieved from sorption isotherms.