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Abstract: Desulfurization of JP-5 jet fuel (1172ppmw S) was investigated by π-complexation adsorption with AgNO3 supported on mesoporous silica SBA-15 and MCM-41. The average pore sizes of AgNO3/SBA-15 and AgNO3/MCM-41 were 48.8 and 19.1Å, respectively. The results of JP-5 desulfurization showed that significant sulfur breakthrough occurred at ∼10.0 and ∼15.0mL/g by AgNO3/SBA-15 and AgNO3/MCM-41, respectively, at a space velocity of 1.25h−1. The spent AgNO3/MCM-41 was regenerated by a simple process (heating in air at 200°C) and ∼50% of the sulfur capacity was recovered after the first cycle. Molecular orbital calculations show that Cu+ (as that in CuY zeolite) formed stronger π-complexation bonding with the thiophenic compounds than Ag+ (in AgNO3), as evidenced by experimental heats of adsorption. However, pore diffusion limitation of the large sulfur molecules (alkylated benzothiophenes) became an important factor for desulfurization of high sulfur jet fuels such that the AgNO3-supported mesoporous sorbents yielded substantially better results than Cu(I)Y, although Cu(I)Y was better for a model fuel that contained only small sulfur molecules. Among all sorbents that have been investigated, the AgNO3/MCM-41 sorbent showed the best desulfurization performance for high sulfur jet fuels. [Copyright &y& Elsevier]

Desulfurization of a JP-5 light fraction (841ppmw S) for fuel cell applications was achieved by -complexation adsorption with CuCl and supported on the MCM-41 and SBA-15 mesoporous materials. CuCl/MCM-41, , CuCl/SBA-15 and sorbents were prepared with spontaneous monolayer dispersion of metal halides onto surfaces of supports. These sorbents were characterized with XRD, physical adsorption and CO chemisorption. The results showed that the mesoporous structures remained in the supported sorbents. Desulfurization of JP-5 light fraction with these sorbents was investigated at room temperature. showed by far the highest capacity of selective sulfur adsorption among all known sorbents, and the significant breakthrough occurred at about 50.0ml/g for desulfurization of JP-5 light fraction. The total sulfur content of JP-5 light fraction can be reduced from 841ppmw S to below 50.0ppmw S. The spent was regenerated by purge with benzene at 70°C, and the regenerated was tested again for the desulfurization. The results showed that about 44% and 48% of the sulfur capacity were recovered at breakthrough and saturation, respectively. [Copyright &y& Elsevier]

The adsorptive desulfurization of a mode diesel (300 ppmw S) and a commercial diesel (187.2 ppmw S) using the durable and regenerable Ag/Al-SBA-15, Ni/Al-SBA-15 and Ce/Al-SBA-15 sorbents was investigated in fixed-bed tests. The desulfurization capability of the sorbents was remarkably enhanced by elevating metal ion-exchanging temperature, increasing metal ion-exchanging number of times and using large pore SBA-15 (∼11.55 nm) as the support. Ni/ASL60-4 sorbent, which was prepared by exchanging Ni ions onto the aluminized large pore SBA-15 (∼11.55 nm) at 60 °C with 4 of times, exhibited the highest desulfurization capability. For the desulfurization of the model diesel, Ni/ASL60-4 can remove 0.228 mmol of total sulfur per gram at saturation. For desulfurization of commercial diesel, 7.0 ml of clean diesel (less than 1.0 ppmw S) can be produced over 1.0 g of Ni/ASL60-4. The desulfurization capability of Ni/ASL60-4 can be enhanced a total of 250% compared to Ni/AS20-1. The saturated Ni/ASL60-4 was regenerated in situ by heating in dry air at 350 °C. After generation, the desulfurization capability of Ni/ASL60-4 can be completely recovered even after 3 cycles. The NiO particles were not found on the fresh and regenerated Ni-based sorbents by XRD test. This showed that metal Ni was in the form of Ni ions after the desulfurization and regeneration. This was mainly because the Ni ions can be firmly anchored on the aluminized SBA-15 by ion-exchanging. [ABSTRACT FROM AUTHOR]

Abstract: 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 (75ppmw S benzothiophene and 75ppmw S 3-methylbenzothiophene in 12.19wt.% benzene and 87.78wt.% 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. [Copyright &y& Elsevier]