Catalytic Dehydrogenation and Cracking of Cyclohexane over Ni/Al<sub>2</sub>O<sub>3</sub> Solids

Sultan, E.A.; Ahmad, Abdel Kader S.; El-Shobaky, G.A.; Ayad, Sami Massalami Mohammed Elmassalami

doi:10.1177/026361749501200101

Cited by 2 publications

(1 citation statement)

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“…D'Ippolito et al [45] suggested that there is an optimum ratio of the acid sites to the metal activity characterized by Lewis acid to achieve the ring opening of cycloalkanes. Moreover, Sultan et al [46] concluded that a catalyst of Ni/Al 2 O 3 with Ni weight content of more than 7.9% exhibits cracking over cyclohexane. A similar trend also occurs for the carbon chain range of C 6 -C 12 by comparing the compositions at different pressures but in a much smaller magnitude.…”

Section: Gc-ms Analysismentioning

confidence: 99%

Moderate Hydrogen Pressures in the Hydrogenation of Alkenes Using a Reactor with Hydrogen Gas Self-Inducing Impeller

2022

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The non-oxygenated oil product of the pyrolysis of polypropylene cannot be used directly as an engine fuel due to its high content of alkenes. However, high pressure of hydrogen gas is commonly employed in the hydrotreatment of alkenes to produce alkanes. A semi-batch hydrogenation reaction using a hydrogen gas self-inducing impeller to internally recirculate the hydrogen gas has been implemented in the present work to provide small hydrogen gas bubbles so that the gas dispersion in the liquid phase is intensified. This technique is expected to improve the contact of hydrogen, oil, and the Ni/Al2O3 catalyst, which in turn alleviates high pressures of hydrogen gas. The hydrogenation reaction was performed at 185 °C with an impeller speed of 400 rpm. The pressure was varied from 2 to 8 bar. At the pressure of 2 bar, the main reactions are the hydrogenation of alkenes and cyclization of alkenes leading to cycloalkane formation, while at the pressures of 4, 6, and 8 bar, the main reactions are dimerization or oligomerization and hydrogenation of alkenes. The hydrogenation reaction shifts the carbon chain length in the oil towards the carbon chain length attributed to diesel fuel with more branching as the hydrogen pressure is increased. The gas inducement technique employed in the present work has succeeded in saturating almost all alkenes at moderate pressures (below 9 bar), lower than the pressures used by previous researchers, i.e., above 9 bar.

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Section: Gc-ms Analysismentioning

confidence: 99%