Optimization of Adsorption Parameters Using Central Composite Design for the Removal of Organosulfur in Diesel Fuel by Bentonite-Supported Nanoscale NiO-WO3

Desulfurization using porous materials is based on the capability of a solid sorbent to selectively adsorb organic sulfur-containing compounds. In the present study, different sorbents were prepared by varying the NiO/WO3 loadings onto bentonite for the removal of sulfur from commercial diesel fuel containing approximately 100 ppm total sulfur (S). X-Ray Diffraction (XRD), Fourier Transform InfraRed (FT-IR) spectroscopy, and Scanning Electron Microscopy (SEM) showed the ability of modified bentonite to adsorb dibenzothiophene (DBT) depends strongly on the surface chemistry, particularly on the presence of basic oxygen-containing groups and acid content. A Plackett–Burman Design (PBD) was chosen as a screening method to estimate the relative influence of the factors that could have an influence on the analytical response. The significant variables included: sorbent amount, feed volume, extraction solvent kind, and its volume were optimized using Central Composite Design (CCD). 93.5% removal of sulfur was observed with NiO@WO3@bentonite.