Adsorptive desulphurisation of benzothiophene and dibenzothiophene from model fuels with modified vermiculite

ABSTRACT

Vermiculite clay was modified with calcium oxide in order to remove Dibenzothiophene (DBT) and Benzothiophene (BT) from Model Fuels (1:1 volume mixture of decane and hexadecane). Composite was prepared with a wetness impregnation method. The physicochemical properties of these adsorbents were characterised using thermal gravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), field-scattering scanning electron microscopy (FE-SEM), transient electron microscopy (TEM), and X-ray diffraction (XRD) analysis. The vermiculite-calcium oxide (VE-Ca) composite showed the highest adsorption capacity at an initial concentration of 30 mg/L, adsorbent dose of 120 mg, and contact time of 120 min at 25°C. The highest adsorption capacity for DBT and BT was 85.37 mg.g⁻¹ and 93.7 mg.g⁻¹ on VE-Ca composite, respectively. The adsorption equilibrium data were fitted to pseudo-second order kinetic and Freundlich isotherm models. The results showed the presence of calcium due to $\pi \mathrm{\_}$complexation between Ca²⁺ and thiophenic aromatic rings and chemical bonding between metals and sulphur which would improve the adsorption capacity for desulphurisation.

KEYWORDS:

• Model fuel
• dibenzothiophene
• benzothiophene
• adsorptive removal
• vermiculite

Disclosure statement

The authors declare that they have no competing interests.

Data availability

All necessary data are presented within the manuscript.

Additional information

Funding

This research did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors.