Adsorptive desulfurization of liquid fuels over green cost-effective Cu-Ni bimetallic nanoparticles-modified alum sludge

Abstract

The elimination of sulfur from liquid fuels in the refining process to a particular range to adhere to the environmental restriction with regards to the emission of toxic gasses. To address the limitation of hydro-desulfurization, several techniques have been used including adsorptive desulfurization. Adsorptive desulfurization has been used because of its efficiency and cost-effectiveness of the materials. In this study, Alum Sludge was modified to prepare alum sludge coupled with copper AS/Cu, alum sludge coupled with nickel AS/Ni, and alum sludge coupled with copper-nickel nanoparticles AS/Cu-Ni NPs. A comparative study was performed for the sulfur removal from liquid fuels diesel and kerosene by the Alum sludge coupled with metallic nanoparticles. The produced AS, AS/Cu, AS/Ni, and AS/Cu-Ni NPs were evaluated by Brunauer-Emmett-Teller (BET) analysis, Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), and X-ray Fluorescence (XRF). According to the BET results, AS/Cu had a surface area that was relatively higher at 557.9 (m²/g), while AS/Ni had a surface area that was lower at 127 (m²/g). The percentage rise of Cu metallic NPs from (0.00725 % - 1.69 %) and Ni metallic NPs from 0.0085 % Ni to 0.0595 % Ni was shown by the XRF data. Researchers looked into the effects of adsorbent dose, loaded metal nanoparticles, and adsorption process isotherms. The percentage removal of sulfur increases reaching ≈100 %. In comparison to the alum sludge combined with copper/nickel (AS/Cu-Ni) and the alum sludge combined with nickel (AS/Ni) NPs from both liquid fuels, the AS/Cu-Ni yields a higher percentage of sulfur removal. The experimental adsorption results for kerosene and diesel, which had higher correlation values, were better adapted to the Langmuir model than to the Freundlich and Temkin model, according to the data. The adsorption processes were exothermic, advantageous, and spontaneous. The desulfurization process is conducted responsibly, upholding laws, and institutions, and is based on evidence-based policies.