New Conduct in the Adsorptive Removal of Sulfur Compounds by New Nickel-Molybdenum Adsorbent

Abstract

The article states the first preparation of NiMo layered double hydroxide (LDH) adsorbent for the removal of dibenzothiophene (DBT) form n-heptane solution and desulfurization of gas oil. The existence of (Mo6+) in Ni2+Mo6+ LDH was proven by X-ray photoelectron spectroscopy (XPS), while X-ray diffraction and X-ray fluorescence patterns, Fourier transform infrared spectra, scanning electron microscopy images, and differential scanning calorimetry-thermogravimetric analysis and Brunauer-Emmett-Teller analysis were applied for the composition and surface characterizations. Experimentally, NiMo LDH exhibited a different conduct in the adsorption elimination of sulfur in the existence of aromatics; the sulfur uptake was increased with the increase of the aromatic content in accordance with its own highly charged surface as a result of the formation of +4 balancing charges between Ni2+and Mo6+ through the brucite layers. The material achieved adsorption capacity of 48.8 mg g-1 sulfur for DBT at 25 °C follows a pseudo-second-order kinetic type and Langmuir isotherm. NiMo LDH adsorbent showed a remarked desulfurization of gas oil by 79.6%, although it has a high aromatic content (33%). A π-complexation between the Ssulfur atoms and Mo6+ was proposed through surface adsorption. The material conserved its parental structure and adsorptive activity after being regenerated seven times.