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Dong C.,Dalian University of Technology | Li X.,Dalian University of Technology | Li X.,Liaoning Key Laboratory of Petrochemical Technology and Experiment | Wang A.,Dalian University of Technology | And 2 more authors.
Shiyou Xuebao, Shiyou Jiagong/Acta Petrolei Sinica (Petroleum Processing Section) | Year: 2015

The Pd and Pt hydrodesulfurization (HDS) catalysts supported on coconut shell activated carbon, nut shell activated carbon, and wood activated carbon were prepared by an incipient wetness impregnation method. The HDS catalytic performances of these noble metal catalysts supported on different activated carbons were investigated by using a model feed containing 0.8 % dibenzothiophene (DBT) in decalin. The results indicated that the dispersion of Pd and Pt could be enhanced by increasing the amounts of either the acidic oxygen-containing groups or the basic groups on the surface of the support. In the HDS of DBT over the Pd/C and Pt/C catalysts, the selectivity toward the direct desulfurization pathway (DDS) was higher than that toward the hydrogenation pathway (HYD). Both the HDS activity and the DDS pathway selectivity of the supported Pt catalysts were significantly higher than those of the supported Pd catalysts. The HDS catalytic performances of the Pt/C and Pd/C catalysts were mainly determined by the surface groups of the support and their distributions. An increase of the surface acidic oxygen-containing groups led to an increase of the HYD selectivity and the stability of the Pd and Pt catalysts, but a decrease in their C-S bond cleavage activity. On the other hand, the basic groups showed a positive effect on the C-S bond cleavage activity of Pd/C and Pt/C and a negative influence on their stability. ©, 2015, Science Press. All right reserved. Source


Wang W.,Dalian University of Technology | Wang W.,Yinchuan Energy Institute | Wang A.-J.,Dalian University of Technology | Wang A.-J.,Liaoning Key Laboratory of Petrochemical Technology and Experiment | And 3 more authors.
Huaxue Gongcheng/Chemical Engineering (China) | Year: 2015

Ni2P-NC-PR and Ni2P(25)/SiO2-NC-PR hydrodesulfurization (HDS) catalysts were prepared by non-calcination method, in which the precursors containing Ni (NO3)2 and (NH4)2HPO4 were directly converted to the active phosphide phase by hydrogen plasma reduction (PR) method. The HDS performances of the prepared catalysts were studied by using a model fuel containing mass fraction 0.8% dibenzothiophene in decalin, and the morphologies of the catalysts were characterized by XRD. A mixture of volume fraction 10% H2S/Ar was used to passivate the freshly synthesized catalysts to protect the crystal structures before entering the fixed bed reactor. Experimental results show that the hydrodesulfurization performances of Ni2P-NC-PR and Ni2P (25)/SiO2-NC-PR prepared by PR method are higher than that of Ni2P-C-PR and Ni2P (25)/SiO2-C-PR respectively. XRD characterization results reveal that the catalyst particle size of Ni2P-NC-PR or Ni2P (25)/SiO2-NC-PR is less than that of Ni2P-C-PR or Ni2P (25)/SiO2-C-PR. The catalyst active center of Ni2P-NC-PR or Ni2P (25)/SiO2-NC-PR is more, and its high activity is attributed to the increase in the number of the active center. © 2015, Editorial Office of Chemical Engineering (China). All right reserved. Source


Sun Z.,Dalian University of Technology | Wang A.,Dalian University of Technology | Wang A.,Liaoning Key Laboratory of Petrochemical Technology and Experiment | Li X.,Dalian University of Technology | And 7 more authors.
Shiyou Xuebao, Shiyou Jiagong/Acta Petrolei Sinica (Petroleum Processing Section) | Year: 2013

Ni2P/SiO2 hydrodesulfurization (HDS) catalysts were prepared by a non-calcination method, in which the precursors containing Ni(NO3)2 and (NH4)2HPO4 were directly converted to the active phosphide phase through the temperature-programmed reduction (TPR) procedure. The HDS performances of the prepared Ni2P/SiO2 catalysts were studied with a model fuel containing 0.8% (mass fraction) dibenzothiophene in decalin, and the morphologies of the catalysts were characterized by XRD. The results indicated that the monolayer dispersion threshold of the Ni2P/SiO2 catalysts prepared by the non-calcination method was between 15%-25%(mass fraction). The increase of the active component loading in Ni2P/SiO2 catalyst led to the increase of HDS activity and the decrease of the direct desulfurization pathway selectivity. However, further increase in the active component loading would not affect the particle sizes and HDS activity of the catalyst, when the loading was above the monolayer dispersion threshold. The catalyst prepared by the non-calcination method exhibited a good stability during HDS reaction, and its HDS activity was equal to (when the loading was above the monolayer dispersion threshold) or higher than (when the loading was less than the monolayer dispersion threshold) that of the catalyst prepared by conventional method. The heating program in the TPR method was a key parameter affecting the HDS activity of Ni2P/SiO2. The heating rate at lower temperature region hardly affected the HDS performance of the catalyst, while holding at 400°C for a short period had a positive action to its HDS activity. Source


Han X.,Dalian University of Technology | Li X.,Dalian University of Technology | Li X.,Liaoning Key Laboratory of Petrochemical Technology and Experiment | Wang A.,Dalian University of Technology | And 5 more authors.
Shiyou Xuebao, Shiyou Jiagong/Acta Petrolei Sinica (Petroleum Processing Section) | Year: 2013

Ionic liquid[BMIM][BF4] was synthesized and applied in removing sulfones of oxidized diesel. The effects of extraction time, extraction temperature, stages and volume ratio of ionic liquid to oil on the extractive removal of sulfones were investigated. The results indicated that the desufurization efficiency for oxidized diesel was much higher than that for un-oxidized diesel. At extraction temperature of 30°C and VIL/VOil of 0.5, the sulfur mass fraction of oxidized diesel was reduced from 125.1 μg/g to 6.2 μg/g by three-stage extraction. Compared with the traditional extractant N, N-dimethyl formamide (DMF), [BMIM][BF4] displayed a slightly lower desulfurization efficiency but a higher diesel yield, and the properties of the diesel hardly changed. Source


Wang L.,Dalian University of Technology | Wang A.,Dalian University of Technology | Wang A.,Liaoning Key Laboratory of Petrochemical Technology and Experiment | Li X.,Dalian University of Technology | And 3 more authors.
Shiyou Xuebao, Shiyou Jiagong/Acta Petrolei Sinica (Petroleum Processing Section) | Year: 2012

ZSM-5/MCM-41 mesoporous aluminosilicate molecular sieves with strong acidity and different SiO 2/Al 2O 3 molar ratios (denoted as ZM(x), where x represented the SiO 2/Al 2O 3 molar ratio of the mother liquid) were hydrothermally synthesized by assembling zeolite subunits, which were generated by the hydrolysis of ZSM-5 in a Na 2SiO 3 aqueous solution, in the presence of cetyltrimethylammonium bromide. The hydrodesulfurization (HDS) of dibenzothiophene (DBT) catalyzed by Pd and Pt catalysts supported on Si-MCM-41 and ZM(x) was studied by using a model feed containing 0.8% DBT in decalin. The results indicated that the mesoporous structure of ZM(x) was reserved after the loading of Pd and Pt. HDS of DBT over the supported Pd catalysts occurred mainly through hydrogenation (HYD) pathway, whereas both HYD and direct desulfurization(DDS) pathways played an important role in DBT HDS over the supported Pt catalysts. Si-MCM-41 supported catalysts exhibited low HDS performance and deactivation quickly. The hydrogenation activity, HDS activity, hydrocracking activity and stability of Pd and Pt catalysts were all improved when ZM(x) mesoporous aluminosilicate molecular sieves were used as the supports. The HDS performance of the Pt and Pd catalysts supported on ZM(x) could be affected by the metal dispersion and the ratio of Brønsted acid sites to Lewis acid sits (B/L ratio) of the supports. Therefore, ZM(60) supported Pd and Pt catalysts, which possessed high metal dispersion and B/L ratio, showed the best HDS performance among the catalysts studied. Source

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