Durable and regenerable mesoporous adsorbent for deep desulfurization of model jet fuel

A series of mesoporous adsorbents were prepared by grafting Ag+, Ni2 + and Ce3 + onto aluminized MCM-41, SBA-15 and SBA-15-L (where SBA-15-L denotes large pore SBA-15) supports. The adsorbents were characterized by XRD, N2 adsorption, ICP-AES, SEM-EDS, TG and were investigated for desulfurization of a mode jet fuel (75 ppmw S benzothiophene and 75 ppmw S 3-methylbenzothiophene in 12.19 wt.% benzene and 87.78 wt.% n-octane) by selective adsorption of thiophenic molecules. For the adsorbents with Ag cation as the active site, the sulfur capacity followed the order: Ag/Al-SBA-15-L > Ag/Al-SBA-15 > Ag/Al-MCM-41. The sulfur capacity of the adsorbents increased with increasing the pore size not with BET surface area of supports. The desulfurization results also showed that the adsorption ability of metal cations followed the order: Ce3 + > Ni2 + > Ag+. The spent adsorbents were regenerated by burning the adsorbed organic sulfur compounds in dry air at 350 °C and the regenerated Ag/Al-SBA-15-L adsorbent was tested for reuse. After generation, the sulfur capacity of Ag/Al-SBA-15-L can be recovered completely. This showed that a stable and regenerable mesoporous adsorbent can be obtained by anchoring the metal cations onto the aluminized mesoporous supports.