Performance of gamma-Al2O3 decorated with potassium salts in the removal of CS2 from C5 cracked distillate

Deep desulfurization is a key process for the production of high value-added products from C-5 distillates. In this work, different potassium salt modified gamma-Al2O3 adsorbents were prepared by an incipient-wetness impregnation method and characterized by N-2 adsorption-desorption, SEM-EDS, TEM, CO2-TPD, XRD, FT-IR, and IC. The C-5 distillate with a 1200 mu g mL(-1) sulfur content is desulfurized to less than 10 mu g mL(-1) within 24 hours by the static adsorption method. For the desulfurization in the fix-bed reactor, the breakthrough sulfur capacity of K2CO3-decorated gamma-Al2O3 reaches 0.76 wt% under the optimized conditions, viz., at 30 degrees C, with a sulfur content of 50 mu g mL(-1) in the raw oil, and a liquid hourly space velocity of 1 h(-1). The desulfurization activity of the exhausted adsorbent can be recovered after regeneration. Selective adsorption of CS2 includes three processes: adsorption, hydrolysis, and oxidation. CS2 is first adsorbed on the adsorbent and hydrolyzed to form H2S. H2S is further oxidized to form S/SO42-, and then deposits on the surface of the adsorbent. Adsorption, hydrolysis, and oxidation all play essential roles in the removal process of CS2.