Titanium Modified USY Zeolite-based Catalysts for Hydrocracking Residual Oil (Part 1) Preparation and Activity Test of Molybdenum Supported Catalysts

• Published in: Journal of the Japan Petroleum Institute Vol. 46; no. 4; pp. 249 - 258
• Main Authors: HONNA, Kosaku, ARAKI, Yasuyuki, ENOMOTO, Toshiyuki, YOSHIMOTO, Masao, SHIMADA, Hiromichi
• Format: Journal Article
• Language: English
• Published: Tokyo The Japan Petroleum Institute 01.07.2003; Japan Science and Technology Agency
• Subjects: Hydrocracking; Mesopore; Molybdenum catalyst; Residual oil; Titanium modification; USY zeolite
• ISSN: 1346-8804; 1349-273X
• DOI: 10.1627/jpi.46.249

New USY zeolite-based hydrocracking catalysts were developed to meet the increasing demand for producing clean middle distillates from residual oil. Titanium modified USY zeolite was prepared by treatment with a titanium sulfate aqueous solution, followed by loading of molybdenum species with the equilibrium adsorption method. In the hydrocracking of Arabian Heavy Atmospheric Residue (AH-AR), molybdenum loaded Ti-modified zeolite catalysts gave higher conversion of residual fraction and higher selectivity to middle distillates than reference zeolite-based catalysts without Ti modification. The Ti-modified zeolite had larger mesopore volumes with diameters larger than 10 nm and lower acidity than the starting USY zeolite. Characterization results indicated that the Ti modification removed extra-framework Al-species but did not destroy the zeolitic framework. Transmission electron microscopy revealed that the Ti-modified zeolite contained TiO2 ultra-fine particles with diameters smaller than 10 nm, on which MoS2 clusters with 5-7 layers and lengths of several nm were loaded with edge-bonding. The higher performances of the Ti-modified zeolite-based catalysts were caused by the larger mesopore volumes and high synergy between the hydrogenation function catalyzed by the molybdenum sulfide on titania and the controlled hydrocracking function catalyzed by the zeolitic framework.