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.