Hydrodesulfurization of Fluidized Catalytic Cracking Diesel Oil over NiW/AMB Catalysts Containing H-Type β-Zeolite in Situ Synthesized from Kaolin Material

• Published in: Energy & fuels 2009-08, Vol.23 (8), p.3846-3852
• Main Authors: Wan, Guofu, Duan, Aijun, Zhang, Ying, Zhao, Zhen, Jiang, Guiyuan, Zhang, Dengqian, Gao, Zhenyong, Liu, Jian, Chung, Keng H
• Format: Article
• Language: English
• Subjects: Catalysis and Kinetics
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/ef900178n

A series of hydrodesulfurization (HDS) catalysts of Ni−W supported on γ-Al2O3-MB (denoted as AMB) composites with various amounts of H-type β zeolite (denoted as MB) synthesized from kaolin were prepared. The samples were characterized by means of N2 physisorption, XRD, SEM, TPR, HRTEM, XPS, and FT-IR spectroscopy of pyridine adsorption. The characterization results showed that, compared with NiW/Al2O3, the addition of MB reduced the interaction between W and the support. The addition of MB made the WS2 slabs grow larger and the stacking degree become higher. The addition of MB also enhanced the overall acidity of AMB supports and led to an increase in the ratio of Brönsted acid of the NiW catalysts. W exhibited higher sulfidation extent in MB-containing NiW/AMB3 catalyst than that in NiW/Al2O3. The fluidized catalytic cracking (FCC) diesel HDS activity changed with the addition of varying amounts of MB on NiW/AMBi catalysts. The optimal MB content was 32 wt % in composite AMB support. A higher deep HDS efficiency was achieved on NiW/AMB3 than that of traditional NiW/Al2O3. Higher HDS activity of NiW/AMB3 was attributed to the appropriate ratio of Brönsted acid to Lewis acid and/or the enhanced hydrogenation activity. For NiW/AMB3 catalyst, the effect of operation conditions on the degree of HDS of FCC diesel was investigated. The ultradeep desulfurization of FCC diesel oil, in which the sulfur content is below 10 ppm, could be obtained under the optimal operation conditions: T = 360 °C, P = 5 MPa, LHSV = 1 h−1, and H2/oil = 600.