The reactive adsorption behavior of thiophene over the reduced NiZnO/Al2O3-diatomite adsorbent was characterized by in situ Fourier transform infrared (FTIR) spectroscopy. X-ray diffraction (XRD) technology was used to investigate the phase change of sulfur species in the reactive adsorption desulfurization (RADS) process. The results indicated that S–M bonding of thiophene on the metallic Ni sites was first decomposed to form Ni3S2 while formed C4 olefins were further saturated by hydrogen to form butane which was released back into the process stream, followed by the sulfur transfer from Ni3S2 to ZnO to form ZnS in the presence of hydrogen, and then the new formed Ni sites could participate in the adsorption of thiophene once again. The muticycle fixed-bed tests showed a good prospect for adsorption desulfurization over the NiZnO/Al2O3-diatomite adsorbents. Thermogravimetric and differential thermal analysis (TG-DTA) together with XRD was used to reveal the regeneration mechanism. The XRD results indicated that the formation of NiSO4 species led to an increase of the amount and the strength of Lewis acid sites in the regenerated adsorbents and, thus, temporarily improved the removal performance of the adsorbent for thiophene.

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Attrition resistance is a key design parameter for catalysts used in slurry phase Fischer–Tropsch (F–T) reactors, especially for industrial-scale reaction. It is well-known that iron F–T catalyst particles undergo physical attrition and chemical stresses caused by phase transformations. Here we report on attrition properties of a Fe–Cu–K–SiO2 catalyst used in a pilot-scale stirred tank slurry reactor (STSR) under low temperature F–T reaction conditions. The wax-free catalysts were characterized by SEM, EDS, BET surface area measurements, and a Mastersizer 2000 for particle size analysis. The results show that, after 408 h of reaction in an STSR, the particle size reduction due to erosion/abrasion and fracture was apparent. Large reductions in the Sauter mean diameter (93.45%) and the volume moment diameter (71.67%) were observed. The increase in the fractions of particles smaller than 5 and 10 μm was 18.25 and 30.11%, respectively. We concluded therefore that the catalyst underwent more severe attrition in industrial application and the attrition was mainly caused by the fracture of larger or smaller particles. Further study is needed to improve the catalyst attrition resistance.

Selective adsorption desulfurization of dimethyl disulfide (DMDS) from methyl tert-butyl ether (MTBE) has been studied on the silicalite-1/CuY core–shell composites. Different copper ion sources (CuCl2, Cu­(NO3)2, and CuSO4) were investigated to form CuY as the core by Cu2+ ion-exchange on NaY zeolite. These silicalite-1/CuY core–shell composites were synthesized at the mass ratio of tetraethyl orthosilicate (TEOS)/tetrapropylammonium hydroxide (TPAOH)/ethanol/H2O/CuY = 20 g:19 g:17 g:87 g:5 g. Results showed that the core–shell Y-CuCl2 displayed the best performance in desulfurization of DMDS with a sulfur adsorption capacity of 32.882 mgs/gadsorbent, owing to its significant mass gain and compact coatings after being coated by silicalite-1 on Y-CuCl2. Also, the preparation process of CuY and the shape selective adsorption mechanism of desulfurizing DMDS from MTBE on the silicalite-1/CuY core–shell composites were expounded.

A high-aluminum-content sulfated zirconia was prepared by the kneading method, and the washing process was considered as a key factor. Catalysts were characterized by XRD, BET analysis, SEM, TG, FT-IR spectroscopy, pyridine IR spectroscopy, NH 3 TPD, H 2 TPR, and 27 Al NMR spectroscopy, and the reactivity was evaluated by n-hexane isomerization. The results showed that the high-aluminum-content sulfated zirconia has a high activity after being washed with water. Moreover, the aluminum content was found to strongly influence the crystal form, catalyst structure, and acidity, as well as the anchoring effect on the labile sulfates. Actually, the higher the aluminum content was, the more sulfates were left in the catalyst samples after washing. The OH and SO stretching vibrations were shifted in the presence of aluminum or water. With the support of the aluminum coordination state, a hydrolysis model was deduced for different aluminum contents in the catalysts, and it can explain the formation of more Brønsted acid sites and AlOS bonds.

Reactive adsorption desulfurization (RADS) experiments were conducted over a series of commercial metal oxide supports (Al 2 O 3 -, SiO 2 -, TiO 2 -and ZrO 2 -) supported Ni/ZnO adsorbents. The adsorbents were characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR), and Fourier transform infrared spectroscopy (FTIR) in order to find out the influence of specific types of surface chemistry and structural characteristics on the sulfur adsorptive capacity. The desulfurization performance of all the studied adsorbents decreased in the following order: Ni/ZnO-TiO 2 > Ni/ZnO-ZrO 2 > Ni/ZnO-SiO 2 > Ni/ZnO-Al 2 O 3 . Ni/ZnO-TiO 2 shows the best performance and the three hour sulfur capacity can achieve 12.34 mg S/g adsorbent with a WHSV of 4 h −1. Various characterization techniques suggest that weak interaction between active component and support component, high dispersion of NiO and ZnO, high reducibility and large total Lewis acidity of the adsorbents are important factors in achieving better RADS performance.

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