Effects of oxidative modification of carbon surface on the adsorption of sulfur compounds in diesel fuel

Role of phosphorus in carbon matrix in desulfurization of diesel fuel using adsorption process

“…So far, in our research effort the highest capacities of total sulfur adsorbed at the breakthrough point of 0.35 and 0.37 mmol-S/g of adsorbent were measured on sulfur and nitrogen-enriched polymer-based carbon, respectively [28,50]. The highest capacities reported by other research groups are 0.36 mmol-S/g of adsorbent on oxidized micro and micro/mesoporous activated carbons (from diesel fuel containing 400 ppmw of sulfur [51]. The total sulfur adsorption capacity on activated carbon without any modification (Nuchar SA) was reported to be 0.49 mmol-S/g of adsorbent with 687 ppmw sulfur in fuel [7].…”

“…The selectivities reported in the literature are 3.0 and 4.5 for DBT and DMDBT for the micro/mesoporous carbon [7] and 3.9 and 4.9 for DBT and DMDBT on microporous activated carbon [51].…”

“…Two peaks with maxima at about 350 and 480 o C were assigned to the removal of DBT and DMDBT (first peak) and their oxidation products (sulfoxides and sulfones), which have higher boiling points than their parent compounds [54]. The oxidation of DBT and DMDBT on the modified carbon was suggested as one of the route of reactive adsorption leading to efficient desulfurization [22,23,27,28,51]. As a result of the increasing polarity of the compounds to be removed, their removal selectivity increases when polar groups containing oxygen or sulfur are present on the surface.…”

Pd-Impregnated activated carbon and treatment acid to remove sulfur and nitrogen from diesel

“…It was noted that the number of acid and basic sites increased as a function of the time and temperature of activation. An improvement in the adsorption associated with acid groups was observed by Ania and Bandosz [6], Zhou et al [7] and Singha et al [8].These groups are probably centers for the adsorption of Dibenzotiophene DBT via oxygen-sulfur or sulfur-sulfur interaction.…”

“…The Table 2 show the results of characterization of pores from activated carbon samples, these parameters are important to adsorption of sulfur and nitrogen compounds, how much greater the available surface area and larger micropores volume is more efficient adsorption [7]. Therefore these parameters were considered to select the AC sample to continue the study.…”