Dehydrogenation Of Methyl-cyclohexane Under A Multi-phase Reaction Condition

Hydrogen is regarded as a promising alternative fuel for automobile in the future. Although the R&D of the onboard fuel cell and the hydrogen internal-combustion engine have made great progresses in technology, a high efficient, safe and economical onboard hydrogen resource is in urgent need. In this paper, we studied the dehydrogenation process of methyl-cyclohexane on the "wet-dry multiphase" reaction condition.From the aspect of dynamic energy balance, this paper studied the multiphase dehydrogenation of methylcyclohexane (MCH) catalyzed by Raney-Ni in small glass equipment. The influences of reaction temperature (483K-573K), the amounts of reactant (0.2mL-4.0mL) and catalyst (2g-10g) on the conversion were investigated. During the reaction, the evolved gases were constantly separated through condenser from the system and collected in the 400ml measuring cylinder. Comparing the curves of dehydrogenation behavior of methyl-cyclohexane and the temperature changes on the catalyst surface, we found that the analyses and understanding of the phenomenon on catalyst surface at the initial reaction stage were critically important to the dehydrogenation of methyl-cyclohexane. The "wet-dry" multiphase condition formed on the catalyst surface was beneficial to dehydrogenation reaction, and closely connected with reaction temperature, the amounts of reactant and catalyst. Under the reaction conditions of 523K, 0.5mL MCH and 8g Raney-Ni, the dehydrogenation conversion was up to 65%.We also selected some hydrogen storage alloys, which behaved good catalysis activities for hydrogenation, as the dehydrogenation catalysts, and studied their catalysis activities for dehydrogenation of methyl-cyclohexane, and the characteristics of the topography and morphology of those hydrogen storage alloys were studied by means of SEM.