Deep Desulfurization of Diesel Feedstock by Selective Adsorption of Refractory Sulfur Compounds

Adsorptive desulfurization was studied using straight-run gas oil (SRGO) with various sulfur contents (390 and 60 ppm S). Immobilization of electron-poor molecules (pi-acceptors) on macroporous resins was achieved in three steps starting from commercially available poly(styrene-co-divinylbenzene) beads. Influence of the temperature on adsorption was Studied, and the process was examined on the basis of breakthrough curves. The regeneration of the support was studied using fixed-bed technology and was efficiently performed with toluene as the solvent. The extracted compounds were easily recovered after evaporation of the toluene and the affinity of the resins toward alkyldibenzothiophenes was confirmed by GC-FPD analysis. On the basis of these preliminary experimental results, a new concept is proposed for ultradeep desulfurization of SRGO.