هانيه جعفرابادي

In this study, the removal process of sulfur compounds from real diesel fuel using nickel ion-modified clinoptilolite zeolite (Ni‑CZ) was investigated. The selec‎ted diesel fuel had an initial sulfur concentration of 329 ppm. First, the natural zeolite was modified via ion‑exchange with nickel ions an‎d then characterized using XRD, FE‑SEM/EDS, BET, XRF, FTIR, an‎d TGA analyses. The results of these analyses showed that the incorporation of nickel ions led to an increase in specific surface area, the development of mesopores, an‎d the formation of new active sites while preserving the crystalline structure of the zeolite.The desulfurization process was designed as a two‑step adsorption–extraction system. To determine the optimal operating conditions, the Response Surface Methodology (RSM) with a Central Composite Design (CCD) was employed. Three main variables—including adsorbent dosage (0.1–0.4 g), fuel volume (5–10 mL), an‎d mixing time (60–180 min)—were investigated at ambient temperature. Statistical analysis revealed that all variables had significant effects on sulfur removal efficiency an‎d that the proposed model exhibited good predictive accuracy. Under the optimum conditions, the nickel‑modified zeolite (Ni‑CZ) achieved a sulfur removal efficiency of 80.24%. The kinetic behavior of sulfur adsorption on Ni‑CZ was fitted to pseudo‑first‑order, pseudo‑second‑order, an‎d intra‑particle diffusion models. The results indicated that the pseudo‑second‑order model best described the experimental data (R² = 0.9998), suggesting that the predominant mechanism was chemisorption, arising from strong surface interactions between sulfur compounds an‎d the active Ni‑CZ sites. To eva‎luate the regenerability of the adsorbent, the sample underwent five consecutive adsorption–regeneration cycles, where regeneration was carried out by thermal calcination. The results showed that the total efficiency loss after five cycles was only 16.66%, an‎d the adsorbent retained more than 83% of its initial performance—indicating excellent cyclic stability an‎d reusability potential.

گوگردزدايي جذبي , گوگردزدايي استخراجي , گازوئيل , زئوليت كلينوپتيلوليت , روش سطح پاسخ , نيكل

Adsorptive desulfurization , Extractive desulfurization , Diesel fuel , Clinoptilolite zeolite , Response Surface Methodology , Nickel

Hanieh Jafarabadi

Dr. Ahad Ghaemi