| The primary aim of this study was to assess the technical feasibility of using the adsorption process as a "polishing" step in the purification of gasoline to lower sulfur content below 100 ppm.; The process variables studied included the type of adsorbent, the nature and concentration of adsorbent promoter (salts of heavy metals), the type of sulfur compounds found in gasoline (thiophene, benzothiophene, and dibenzothiophene), composition of the hydrocarbon mixture, and the process temperature.; Among the adsorbent tested, the NaX zeolite was found be most effective for removal of organic sulfur compounds from a model hydrocarbon mixture. The maximum sulfur uptake on NaX zeolite was found to be 0.05 mole/kg. The efficiency of sulfur removal depends on concentration of aromatics in solution. The proposed adsorption process for sulfur removal is found to be technically feasible as a polishing step in an overall process train for gasoline purification. |
