Influence of aluminium impregnation on activated carbon for enhanced desulfurization of DBT at ambient temperature: Role of surface acidity and textural properties

The influence of aluminium concentrations (0.05–10 wt.%) in activated carbon (AC) on the comparative improvement of the adsorbent materials for adsorptive desulfurization of dibenzothiophene (DBT) in isooctane at room temperature was studied. The adopted extensive spectroscopic and N2 physiosorption techniques revealed the physicochemical properties of the developed adsorbents, which were associated with the estimated adsorption activity parameters. The Al-incorporated AC samples showed better adsorption properties than the pure AC such that a maximum adsorption capacity of 95% in 200 ppm-S compound (as in dibenzothiophene, DBT) was obtained for AC-Al-2.5 wt.% adsorbent. The enhanced desulfurization of DBT was associated with the tetrahedral coordination of Al in AC-Al composite. The adsorption of DBT onto AC-Al-2.5 wt.% followed pseudo second order kinetics and was best-fit by Freundlich isotherm. Furthermore, the spent adsorbent possessed good regeneration potential for further desulfurization cycles with adsorption capacity similar to that of a fresh adsorbent.