Control of Macropore Structure of Hydrocracking Catalyst by Silica-alumina Particle Size and Influence on Hydrocracking Activity and Middle Distillate Selectivity
| Autor: | Seiji Togawa, Manabu Kobayashi, Hiroshi Yachi, Katsuaki Ishida |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Journal of the Japan Petroleum Institute. 50:278-282 |
| ISSN: | 1349-273X 1346-8804 |
| Popis: | Hydrocracking (HC) catalysts consisting mainly of silica-alumina and a small amount of ultra stable Y type (USY) zeolite were prepared with silica-alumina powders of different mean particle sizes, and the effects of particle size on the pore structure and HC catalytic performance were investigated. The structures of the macropores depended on the average particle size of the silica-alumina powder, with larger particle size resulting in larger mean pore diameter. The HC activities of prepared catalysts for straight run vacuum gas oil were also evaluated. Up to 300 nm, larger pore size led to higher HC activity, but pore size larger than 400 nm led to lower HC activity. These results suggest that there is an optimum macropore diameter for HC activity. Smaller macropore size provided higher middle distillate selectivity. This result suggests that the smaller macropores allow middle distillate oil molecules to escape easily, and avoid secondary cracking. These results indicate that selecting the optimum silica-alumina particle size for high diffusivity in HC catalysts is important to enhance catalytic activity without loss of middle distillate selectivity. |
| Databáze: | OpenAIRE |
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